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Aims Methods and results Conclusions Recently, SOX17 has emerged as a promising biomarker for non‐mucinous Müllerian (ovarian and endometrial) carcinomas, demonstrating increased specificity in comparison to PAX8 while maintaining similar sensitivity. However, expression of SOX17 in mesonephric‐like adenocarcinoma (MLA), a carcinoma of the female genital tract with uncertain, but probably Müllerian histogenesis, remains unexplored. This study aims to address this gap.SOX17 immunohistochemistry was performed on whole tissue sections from 68 MLAs originating from the endometrium or ovary and seven cervical mesonephric carcinomas, as well as six mesonephric remnants/hyperplasias. Using a four‐tiered scoring system based on distribution and intensity of staining, 68% of MLA displayed a negative/low (< 10%) SOX17 expression pattern, which contrasts with the high expression observed in most Müllerian carcinomas. However, 22% of MLA demonstrated high SOX17 expression, similar to other endometrial and ovarian carcinomas. Similarly, five of seven (72%) mesonephric carcinomas of the cervix were SOX17‐negative, but two cases (28%) were positive. All mesonephric remnants/hyperplasias were SOX17 negative.The majority of MLA are negative or exhibit low SOX17 expression, in contrast to the diffuse and strong expression commonly seen in other types of Müllerian carcinoma. However, a subset of MLAs demonstrate high SOX17 expression. Therefore, absence of SOX17 staining is supportive for MLA when the differential includes another non‐mucinous Müllerian carcinoma. SOX17 may also be useful for differentiating mesonephric remnants/hyperplasias from Müllerian malignancies and benign Müllerian glandular lesions. [ABSTRACT FROM AUTHOR]

Thyroid tissue in teleosts is located mainly in the pharyngeal region, usually reaching other adjacent anatomical locations. Herein, a nodular lesion located in the left operculum of a Senegal seabream (Diplodus bellottii) was surgically excised and sent for microscopical evaluation. Microscopically, the lesion presented irregular borders and consisted in columnar epithelial cells arranged in a tubulopapillary pattern, surrounding a central lumen filled with acellular, acidophilic and homogeneous, material (‘colloid’). To determine the lesion's histogenesis, immunohistochemistry was performed employing antibodies for AE1/AE3, CK7, thyroglobulin and vimentin. The neoplastic cells presented low mitotic index and positive immunolabelling for CK7 and thyroglobulin. Therefore, a diagnosis of ectopic thyroid adenoma was made. Herein, the successful employment of antibodies classically used in mammals for accurate diagnosis of thyroid disorders is described. Proliferation of thyroid tissue in fish may reflect environmental and physiological imbalances, making the study and correct diagnosis of these tumours in this species important. [ABSTRACT FROM AUTHOR]

Lhermitte-Duclos Disease (LDD) is a rare condition characterized by a cerebellar mass composed of dysplastic ganglion cells. It is classified as a glioneuronal and neuronal tumor. The exact nature of LDD is still unclear, with debate over whether it is hamartomatous or neoplastic in nature. LDD is associated with Cowden syndrome (CS), a rare genetic disorder that increases the risk of certain cancers. The activation of the PTEN/AKT/mTOR pathway is believed to play a role in the pathogenesis of LDD. Diagnosis of LDD may prompt further screening for CS and associated malignancies. Surgical resection is the main treatment for LDD, and long-term follow-up is important for early detection of associated malignancies. [Extracted from the article]

Despite common histogenesis meningiomas have a wide morphologic spectrum, and the World Health Organization (WHO) recognizes 15 subtypes. They are the most common brain tumour in adults and typically have an extra‐axial location. Although there have been important advances in the molecular biology of meningiomas its diagnosis is based on histopathologic features. The great majority are benign WHO grade 1 tumours. There are specific criteria for assigning WHO grade 2 and 3 that can be applied to all meningioma subtypes. Regardless of these criteria, chordoid and clear cell morphologic subtypes are considered grade 2. WHO grade 3 tumours exhibit a very high mitotic index, frank anaplasia or specific molecular abnormalities. The impressive morphologic diversity shown by meningiomas makes them a diagnostic challenge, which can be even greater in intraoperative studies. The focus of this article is to describe and illustrate their main cytologic features, with emphasis on the most infrequent subtypes. [ABSTRACT FROM AUTHOR]

The current World Health Organization (WHO) classification of central nervous system (CNS) tumours includes several neoplasms that, while occurring in this location, are more frequently seen extracranially. These include mesenchymal, melanocytic and haematolymphoid neoplasms, as well as metastases. A few of these entities are exclusive of the CNS and have no extracranial counterpart. Despite their diverse histogenesis, these neoplasms share a peculiar predilection for involving meningeal structures. In fact, in the context of an intraoperative pathologic consultation of a meningeal tumour, virtually all these entities should be considered as potential diagnoses. Metastases in the CNS are very common. Most are carcinomas that cytologically resemble their site of origin. Loss of differentiation with cell dissociation and anaplasia and presence of accompanying fibrillary brain parenchyma can be a source of diagnostic problems. In this review, we intend to show the most relevant cytologic features of these tumours, and it is especially aimed at their analysis during intraoperative studies. [ABSTRACT FROM AUTHOR]

Background: Mainly known as a transcription factor patterning the rostral brain and governing its histogenesis, FOXG1 has been also detected outside the nucleus; however, biological meaning of that has been only partially clarified. Results: Prompted by FOXG1 expression in cytoplasm of pallial neurons, we investigated its implication in translational control. We documented the impact of FOXG1 on ribosomal recruitment of Grin1-mRNA, encoding for the main subunit of NMDA receptor. Next, we showed that FOXG1 increases GRIN1 protein level by enhancing the translation of its mRNA, while not increasing its stability. Molecular mechanisms underlying this activity included FOXG1 interaction with EIF4E and, possibly, Grin1-mRNA. Besides, we found that, within murine neocortical cultures, de novo synthesis of GRIN1 undergoes a prominent and reversible, homeostatic regulation and FOXG1 is instrumental to that. Finally, by integrated analysis of multiple omic data, we inferred that FOXG1 is implicated in translational control of hundreds of neuronal genes, modulating ribosome engagement and progression. In a few selected cases, we experimentally verified such inference. Conclusions: These findings point to FOXG1 as a key effector, potentially crucial to multi-scale temporal tuning of neocortical pyramid activity, an issue with profound physiological and neuropathological implications. [ABSTRACT FROM AUTHOR]

he 2014 World Health Organization classification identifies ovarian seromucinous tumors as one of the six categories of epithelial ovarian tumors. Ovarian seromucinous tumors encompass adenomas, atypical proliferating (borderline) tumors, and invasive carcinomas. These tumors are exceedingly rare, with benign instances accounting for a mere 1% and 25% of borderline cases among all atypical proliferating tumors. The rarity of seromucinous cancer means its prevalence has not been thoroughly investigated, which has resulted in this group of tumors remaining incompletely researched.

Pleomorphic adenoma, usually referred to as a ‘benign mixed tumor,’ is the ‘most prevalent’ salivary gland neoplasm. It typically arises in the parotid gland, one of the main salivary glands, and has a limited development potential. Pleomorphic adenoma can also occur in minor salivary glands located in the pharynx, oral cavity, and other areas. The purpose of this paper is to provide an overview of the histology, therapy, and clinical features of pleomorphic adenoma in a number of patients. This case series provides an overview of key characteristics, clinical presentation, diagnosis, and management of pleomorphic adenoma. A review of the update of histogenesis is also explored. Pleomorphic adenoma is typically characterized by its histological diversity. Early diagnosis, accurate imaging, and surgical intervention are crucial for effective management and avoiding potential complications. Regular surveillance following treatment helps ensure optimal patient outcomes. Pleomorphic adenoma can grow to large sizes, if untreated and hamper normal function. Hence early diagnosis and treatment are needed. The varied histopathological presentation of pleomorphic adenoma makes the diagnosis challenging in certain cases. Timely diagnosis and prompt treatment planning require a detailed history and clinical evaluation with radiographic and histopathological investigations. Thus, by documenting these instances, healthcare providers can enhance their ability to recognize and manage unusual presentations of the disease. This, in turn, helps in early diagnosis and appropriate treatment selection. [ABSTRACT FROM AUTHOR]

The present study focused on the histogenesis of the crop in quail embryos. The developmental sequence was recorded from day 10 of incubation to the hatching day (17th day) by gross anatomy, morphometric analysis and by using light and scanning electron microscope (SEM). Grossly, the crop was distinguished as an enlarged pouch of the cervical oesophagus on the 12th day of incubation. Histologically, the development of the crop began on the 10th day of incubation. The muscularis mucosae was observed as a small, thin layer of myoblast cells on the 10th day, then it appeared as longitudinally arranged smooth muscle fibres with progression of the developmental age till hatching day. The submucosal layer was also observed on the 10th day, while the lamina propria, muscular layer (inner circular and outer longitudinal layers of smooth muscle fibre) and glandular primordia were detected on the 12th day. The epithelial cells of crop revealed affinity for PAS stain and AB‐PAS on the 10th day of incubation till the 17th day, while the affinity for AB stain appeared on the 14th day of incubation. Additionally, the glandular cells showed the positive for AB, PAS and AB‐PAS on the 12th day of incubation. SEM sections showed variable sizes of the openings of the oesophageal glands. In conclusion, the present study provided a detailed overview of the histogenesis of the crop in quail embryos. [ABSTRACT FROM AUTHOR]

Testicular descent is a complex process that only occurs in mammals. The role of the gubernaculum during testicular descent has been explained mainly by its capacity for dilatation and contraction. This study tried to investigate the changes in the structure of the fibers and cells of the gubernaculum in different age levels of testicular descent in goat fetuses. Embryo samples were collected and grouped in such a way that 60 male goat fetuses were obtained from 100 pregnant does (Capra marghoz). The samples were classified based on the average length (CRL) of the used embryos into 6 age groups. Tissues of the gubernaculum were stained using Masson's Trichrome method to observe collagen fibers under light microscopy. In the present study, growth and orientation of collagen fibers of gubernaculum were observed from the age of 51 days in a manner that the arrangement and order of fibroblasts and collagens to be associated with the onset of testicular migration order and collagen fibers until the end of the third month. Further, changes in the cell arrays and strings were observed after the age of 111 days in such a way that near the birth date, the gubernaculum converted into atrophy tissue. It can be said that from the beginning of the period of testicular descent until its completion, the tissue of the gubernaculum undergoes cellular changes, such as deformation and increase and secretion in connective fibers. [ABSTRACT FROM AUTHOR]

The germination and post-seminal development of Arecaceae are notably complex due to the microscopic dimensions of the embryonic axis, the occurrence of dormancy, and the diversity of reserve compounds. In-depth information on this subject is still limited, especially in terms of the basal sub-family Calamoideae. Mauritiella armata is widely distributed in the Amazon region and is considered a key species in flooded ecosystems (veredas) in the Cerrado biome. We sought to describe histogenesis and reserve compound dynamics during the germination of M. armata, as well as the changes in incubated seeds over time. Seeds with their operculum removed (the structure that limits embryonic growth) were evaluated during germination using standard methods of histology, histochemistry, and electron microscopy. Evaluations were also performed on intact seeds incubated for 180 days. The embryos show characteristics associated with recalcitrant seeds of Arecaceae: a high water content (>80%), differentiated vessel elements, and reduced lipid reserves. Both the embryo and endosperm store abundant reserves of proteins, neutral carbohydrates, and pectins. The completion of germination involves cell divisions and expansions in specific regions of the embryo, in addition to the mobilization of embryonic and endospermic reserves through symplastic and apoplastic flows. Intact seeds show dormancy (not germinating for 180 days), but exhibit continuous development associated with cell growth, differentiation, and reserve mobilization. The anatomical and histochemical characters of M. armata seeds indicate an association between recalcitrance and dormancy related to the species' adaptation to flooded environments. [ABSTRACT FROM AUTHOR]

Serial sectioning and 3D image reconstruction methods were applied to elucidate the structures of the apices of root vascular cylinders (VCs) in taxa of the Poaceae: Zea mays "Honey Bantam", Z. mays ssp. mexicana, Hordeum vulgare and Oryza sativa. The primary and nodal roots were investigated. Observations were performed using high-quality sectioning and 3D image-processing techniques improved and developed by the authors. We found that a quiescent uniseriate plerome was located at the most distal part of each VC. Vascular initials were located immediately basipetally to the plerome as a specific uniseriate layer that could be classified into central and peripheral initials that produced all the cells in the VC. No supplying of cells from the plerome to the vascular initials was observed. Numerical analysis revealed a "boundary point" along the root axis where the rate of increase of the vascular cell number markedly declined, and the VC diameter, number of vascular cells, and number of late-maturing metaxylem vessels (LMXs) at that point showed a similar relationship among the taxa and the types of roots examined (primary vs. nodal). The plerome and vascular initials layer can be considered independent after seed germination in these taxa. A boundary point at which procambial cell proliferation sharply declined was identified. The diameters of the VCs, number of LMXs, and number of vascular cells at the boundary point were found to be strongly related to each other. [ABSTRACT FROM AUTHOR]

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterised by neuronal dysconnectivity which leads to impairment in language, behavioural and intellectual disability. The development of the autistic brain is presented as an initial neuronal overgrow which is followed by a rapid decline from adolescence to middle age. Although the exact cause still remains unknown, there are evidences involving apoptotic mechanisms in autism. Apoptosis occurs normally during normal histogenesis and organogenesis and has a crucial role maintaining a dynamic tissue equilibrium by regularly replacing mature cells of various organs. In the developing brain of infants with autism, there are deficiencies in apoptosis, while in childhood and adolescence autistic individuals there is an excess of "programmed cell, the proteins Brain-Derived Neurotrophic Factor (BDNF) and interleukin 1 beta (IL1β) could be involved in a new research direction aimed at investigating their roles in apoptotic processes in the autistic brain. In conclusion, based on the analyze of the scientific evidences, the apoptotic dysregulation is very important in the autistic brain as well as the interplay between proinflamatory citokines IL-1B and neurotrophic factors including BDNF. Future direction should establish more clearly the exact place of this phenomena which may have relevance with respect of therapeutic approaches. [ABSTRACT FROM AUTHOR]

The primordial anlage of sublingual gland was first noticed as a solid epithelial bud from oral epithelium at the 24th day of foetal development. The terminal buds were arranged in the form of clusters with undifferentiated epithelial cells and terminated in a bulb-like structure in the 30-day-old sheep foetus. On the 37th day, lumenization and branching of the main cord was noticed. The primary septa were observed from the 55th day onwards which resulted in the formation of lobulation on the 60th day. The capsule formation was initiated by aggregation of mesenchymal tissue on the 63rd day. On the 100th day, terminal tubules differentiated to form secretory end pieces. Tubular portions formed intercalated and striated ducts. Predominantly mucous type of acinar cells was seen from the 110th day onwards with myoepithelial cells. The number of lobules increased with increase in parenchyma from 130th day onwards. Micrometrical studies revealed that the mean diameter of acini, intercalated, striated and large ducts was increased with advancement of age and significant differences were observed between groups. Localization of acidic and neutral mucopolysaccharides were observed in mucous and goblet cells. Fine lipid droplets were observed in intralobular and interlobular connective tissue however, phospholipids were observed in cell membrane of acini and ducts. The current investigation provides microstructural standards for the organogenesis of the sublingual gland of miniature sheep and can lay the foundation for further studies in the morphological investigation of salivary gland development. [ABSTRACT FROM AUTHOR]

Background: A tibial defect greater than 4 cm is a common clinical entity, particularly among populations with sever acute trauma, infection sequalae, congenital pseudoarthrosis tibia, and following tumor resection. Segmental bone transport by using an Ilizarov external fixator has become the treatment of choice. The aim of this prospective study was to evaluate the results of using the Ilizarov fixator in the treatment of tibial defects, its advantages, and its complications. Methods: Our prospective study was conducted involving 44 cases with tibial defects (from 4 to 15 cm) of different causes. All patients are treated by segmental bone transport using an Ilizarov external fixator. All patients were operated on at Zagazig University Hospitals. Results: 44 patients were followed up from March 2018 to December 2021. Infection was eradicated in all cases, and union was achieved in all cases, with no cases of limb amputation. The infection was eradicated in all the infected cases without the need for prolonged antibiotics and without reactivation throughout the period of follow-up. The union was achieved in all cases. Conclusions: Distraction histogenesis is a good solution for segmental tibial defects. The Ilizarov technique is complicated and requires a great deal of expertise to perform successfully. Ilizarov’s bone defect reconstruction was less expensive and easier to perform. Bone graft at the docking site may be needed to enhance the union and shorten the time in fixation. [ABSTRACT FROM AUTHOR]

Internal granular progenitors (IGPs) in the developing cerebellar cortex of ferrets differentiate towards neural and glial lineages. The present study tracked IGPs that proliferated in response to valproic acid (VPA) to determine their fate during cerebellar cortical histogenesis. Ferret kits were used to administer VPA (200 μg/g body weight) on postnatal days 6 and 7. EdU and BrdU were injected on postnatal days 5 and 7, respectively, to label the post-proliferative and proliferating cells when exposed to VPA. At postnatal day 20, when the external granule layer was most expanded, EdU- and BrdU-single-labeled cells were significantly denser in the inner granular layer of VPA-exposed ferrets than in controls. No EdU- or BrdU-labeling was found in Purkinje cells and molecular layer interneurons. Significantly higher percentages of NeuN and Pax6 immunostaining in VPA-exposed ferrets revealed VPA-induced differentiation of IGPs towards granular neurons in BrdU-single-labeled cells. In contrast, both EdU- and BrdU-single-labeled cells exhibited significantly greater percentages of PCNA immunostaining, which appeared in immature Bergman glia, in the internal granular layer of VPA-exposed ferrets. These findings suggest that VPA affects the proliferation of IGPs to induce differentiative division towards granular neurons as well as post-proliferative IGPs toward differentiation into Bergmann glia. [ABSTRACT FROM AUTHOR]

Aims: This study aimed to better characterize the clinical and molecular features in invasive stratified mucin‐producing carcinoma (ISMC), an uncommon aggressive subtype of endocervical adenocarcinoma (EAC). Methods and Results: We recruited 59 ISMC for clinicopathological analysis, immunohistochemistry (n = 56), and targeted next‐generation sequencing (n = 17). Our cases contained 29 pure and 30 mixed‐type ISMC. Five patients developed local recurrence at 6–32 months (median: 13 months), and died of disease at 16–55 months (median: 16 months). Pure and mixed‐type ISMC showed no significant difference in overall survival and tumour relapse (P > 0.05) except larger tumour size in the pure‐type (P = 0.009). Compared to the usual‐type EAC (n = 217), ISMsC were more frequently associated with large tumour size (P = 0.003), advanced FIGO stage (P = 0.017), lymph node metastasis (P = 0.022), Silva pattern C (P < 0.001), and poor overall survival and short tumour recurrence. SOX2 expression was observed in 82.1% (46/56) ISMC, substantially higher than p63 expression (P < 0.001), while positive SOX17 was present in 3.6% (2/56) cases. PD‐L1 was positive in 41/56 ISMC (73.21%) (combined positive score: range: 1–92, median: 22). Three ISMC patients (17.65%) had PIK3CA mutations, while one each (5.88%) patient harboured an ERBB2, TP53, STK11, and PTEN mutation, respectively. Conclusion: We conclude that ISMC is clinically more aggressive than the usual‐type EAC. ISMC may originate from cervical reserve cells with bidirectional differentiation. PD‐L1 overexpression and the molecular profiles raise the possibility that a subset of ISMC patients may benefit from anti‐PD‐L1 immunotherapy and other targeted therapy, such as mTOR inhibitor and T‐DM1. [ABSTRACT FROM AUTHOR]

According to modern phylogenetic data, the monotypic subfamily Enkianthoideae is sister to all other subfamilies of the family Ericaceae s.l. Aiming to determine the peculiarities of development and structure of Enkianthus pericarp and to reveal the principal characters of its structure, which can be original for the Ericaceae, we have studied fruit anatomical structure at different stages of development in four species of the genus Enkianthus belonging to three sections: Meisteria , Enkiantella , Enkianthus. The pericarp of superior loculicidal capsule of Enkianthus is differentiated into three histogenetic zones: (i) one-layered exocarp, (ii) multilayered mesocarp differentiated into two histological zones: the peripheral parenchymatous one, and the inner sclerenchymatous one, and (iii) one-layered endocarp composed of tangentially elongated sclereids. It has been shown that the lignification of cells of the endocarp proceeds after the lignification of the inner zone of the mesocarp. Our investigation demonstrates that the superior loculicidal capsules of Enkianthus are capsules of Hamamelis type, which are recognized as the probable ancestral (plesiomorphic) fruit type for other subfamilies of Ericaceae. This fruit type is recognized as the original in several modes of morphogenetic transformations of fruit in Ericaceae family, from which other types of capsules, pyrenariums, and berries originated. [ABSTRACT FROM AUTHOR]

A 9-y-old Mangalarga Marchador gelding was referred to a veterinary hospital because of a swelling on the upper right side of the neck. Ultrasound examination revealed a multilocular structure adjacent to the thyroid gland with low echogenic content suggestive of fluid. The mass was removed surgically. Histologically, the cystic cavities in the surgical sample were filled with abundant eosinophilic secreta and lined by cuboidal, segmentally ciliated, columnar epithelium with interspersed goblet cells. Segmental crowding of the multilayered lining of the cyst was noted. Immunohistochemistry suggested the presence of both C cells and follicular cells, given the positivity of the immunomarkers calcitonin and TTF-1, respectively. The histogenesis of ultimobranchial cysts is uncertain. Based on clinical, histopathologic, and immunohistochemical identification, the cystic structure in this case is compatible with an ultimobranchial body cyst. [ABSTRACT FROM AUTHOR]

Malignant Brenner tumor (MBT) of the ovary is exceedingly rare, and studies of MBT have been limited to case reports and small case series. MBT shares similar clinical and radiological presentations with other ovarian epithelial malignancies, and the diagnosis of MBT is predominantly based on histopathologic evaluation. Recently, relatively large retrospective studies have advanced understanding of their histogenesis and malignant transformation, as well as on the clinical management of this rare subtype of ovarian carcinoma. In this article, we review the published English literature on MBT, with an emphasis on the histopathologic evaluation, molecular biology, and clinical management of MBT.

Background: Transformation of endometriosis to malignancy is a rare occurrence. Clear cell ovarian cancer and endometrioid ovarian cancer are the two histotypes most consistently linked to endometriosis. The exact pathways leading to malignant transformation of endometriosis remain elusive. Case presentation: A 41-year-old woman presented to our hospital with a ten days history of abdominal pain which was not responsive to medication. Pathological examination revealed an unexpected finding of bilateral endometriosis associated with distinct malignancies: a clear cell carcinoma in the right ovary and a well-differentiated endometrioid carcinoma in the left ovary. Molecular analysis indicated a shared somatic driver mutation in ING1 in the eutopic endometrium and the bilateral ovaries while simultaneously exhibiting specific genetic alterations unique to each carcinoma. Notably, several common mutation sites were also identified, including previously reported common oncogenes (KRAS, PIK3CA, ARID1A). This finding prompts the hypothesis of a possible monoclonal origin of the two tumours. Conclusion: This case represents an exceedingly rare occurrence of two different histotypes of ovarian endometriosis-associated cancer manifesting simultaneously in bilateral ovaries. Based on genetic analysis, we hypothesize that these malignancies may have a monoclonal origin, providing insights into understanding the different biological mechanisms underlying carcinogenesis. [ABSTRACT FROM AUTHOR]

The expansion of human and non-human primate central nervous system structures has been a paramount question for classic and contemporary studies in comparative vertebrate neuroanatomy. These studies can benefit from framing data analysis within the Prosomeric Model, which defines a common Bauplan for all vertebrate species, including mammals. According to this model, the vertebrate nervous system is composed of several Fundamental Morphological Units (FMUs) that are defined and delineated by characteristic gene expression profiles. Thus, the expansion of neural structures can be traced back to heterochronic neurogenesis, cell lineage specification, and axon growth in their corresponding FMUs. In the present article, we exemplify the use of the Prosomeric Model as the proper theoretical framework for analyzing the expansion of the cerebral and cerebellar cortices, the pontine nuclei, the striatum, the nigrostriatal dopaminergic system, the thalamus, and the amygdala in primates compared to rodents. We describe the quantitative (volume and neuron number) and qualitative (cytoarchitectonic and cell type differences) expansion of these structures in primates versus rodents and define different expansion modes. Then, we relate these modes to the developmental primary events of specification and secondary events of histogenesis, like neurogenesis. We conclude that the systematic analysis of the molecular regulation of primary and secondary developmental events in each FMU in rats, primates, and other mammals could provide the necessary insight to identify the causal mechanisms of the expansion modes described in the present article. [ABSTRACT FROM AUTHOR]

Hybrid odontogenic tumours occur rarely in the oral cavity. The basic histogenesis of these lesions is not clear. Hybrid odontogenic tumours characteristically exhibit two or more distinct morphological features that may lead to a diagnostic dilemma. Unicystic Ameloblastomas (UA) are the second most common odontogenic tumour. Ameloblastic Fibro-dentinoma (AFD) is a rare mixed odontogenic tumour. Both UA and AFD commonly occur in the second decade of life, may be asymptomatic with a slight female predilection, and predominantly occur in the mandibular posterior region. Herein, the authors report a rare case of a 15-year-old female patient complaining of swelling in the right lower posterior jaw region in the last two months. The lesion was surgically enucleated and sent for histopathological examination. On histopathological examination, the lesion exhibits areas of both UA and AFD, representing a rare occurrence of a hybrid odontogenic tumour. The present case report highlights the unique combination of two odontogenic tumours of different origins. [ABSTRACT FROM AUTHOR]

Introduction: The thymus is located in the superior mediastinum and anterior part of the inferior mediastinum. It plays a crucial role in the development, differentiation, and clonal expansion of T lymphocytes. In forensic cases involving foetal death, accurate estimation of foetal age is essential. When the foetus is extensively damaged, other organs can be used to estimate age. The thymus, being retrosternal and well-protected, is easily accessible during dissection. Therefore, studying the gross features and histogenesis of the thymus can be helpful in estimating gestational age in cases of severely mutilated foetal specimens. Aim: To examine the morphological features and histogenesis of the thymus in aborted and stillborn foetuses from normal pregnancies. Materials and Methods: A pilot study was conducted using a cross-sectional design at the Department of Anatomy, BLDEDU's Shri BM Patil Medical College, Vijayapura, Karnataka, India, from May 2016 to April 2018. The dimensions and histogenesis of the thymus were studied in a total of 50 human foetal thymus specimens, collected from normal pregnancies across different gestational age groups ranging from 12 to 40 weeks. The specimens were obtained from the Department of Pathology and the Department of Obstetrics and Gynaecology. The dimensions and weight of the thymus were recorded during autopsy. Slides were prepared, stained with Haematoxylin and Eosin (H&E), and examined under a compound microscope. The histogenesis of the thymus was studied to observe its maturation. Results: Foetal weight increased from 134.6±58.3 g at 12 weeks to 1942±598 g at 40 weeks. The weight of the thymus ranged from 0.2 g at 12 weeks to 5.9 g at 40 weeks. Crown rump length varied from 10.7 cm to 29.9 cm. The length of the thymus measured between 0.5 cm and 3.3 cm, breadth between 0.4 cm and 2.3 cm, and height between 0.2 cm and 0.9 cm from 12 to 40 weeks of gestation. Microscopic features observed in the present study at different gestational ages included a well-formed thick capsule at 17 weeks, lobulation starting at 19 weeks, cortico-medullary differentiation beginning at 17 weeks, appearance of epithelial cells around 19 weeks, and initial appearance of Hassal's corpuscles at 17 weeks, with more numbers observed later on. Conclusion: The thymus can be used in forensic investigations to estimate the gestational age of mutilated foetuses. It exhibits varying features at different gestational ages, which can aid in thymectomy procedures. Additionally, these findings can be considered during prenatal imaging studies. [ABSTRACT FROM AUTHOR]

We present a case of lung carcinoma with a unique biphasic feature. The patient was a 67‐year‐old male smoker with idiopathic pulmonary fibrosis (IPF). A subpleural tumor in the left lower lobe, embedded in fibrotic tissue, was resected. Histologically, the tumor consisted of major and minor components of mucoepidermoid carcinoma (MEC) and surrounding conventional lepidic adenocarcinoma, respectively. Both components had the same TP53 somatic mutation (p.V157F) but not Mastermind‐like 2 (MAML2) gene rearrangement. The two components may have developed from an identical origin. The tumor could be trans‐differentiating from lepidic adenocarcinoma to MEC, possibly promoted by IPF‐induced tissue damage. The final diagnosis was "adenosquamous carcinoma with mucoepidermoid‐like features (that may originate from lepidic adenocarcinoma)." This case has implications for the potential histogenesis of peripheral lung MEC. Over time, the MEC would expand and outgrow the lepidic adenocarcinoma, making it impossible to distinguish between fake and true MEC. The present case suggests that peripheral MEC could differ from proximal MEC in its histogenesis and molecular genetics. Thus, careful examination is necessary to diagnose peripheral lung MEC, particularly in patients with interstitial lung diseases. [ABSTRACT FROM AUTHOR]

The concept of "stem cell pathology" is to establish the role of the stem cells by exploring their contribution to lesion development. The somatic stem cells are present in the body. Malignant fibrous histiocytoma (MFH; recently named "undifferentiated pleomorphic sarcoma") includes pluripotential undifferentiated mesenchymal stem cells as a cell element. An antibody (A3) generated by using rat MFH cells as the antigen labels somatic stem cells such as bone marrow stem cells and immature endothelial cells and pericytes, as well as immature epithelial cells in epithelialization. By using A3 and other antibodies recognizing somatic stem cells, it is considered that myofibroblasts appearing in rat fibrotic lesions are developed partly from immature hepatic stellate cells in hepatic fibrosis, immature pancreatic stellate cells in pancreatic fibrosis, pericytes/endothelial cells in neovascularization in injured tissues, as well as via the epithelial-mesenchymal transition. These progenitors may be in the stem cell lineage. In this review, the author introduces the histogenesis of MFH and the characteristics of myofibroblasts appearing in fibrosis, based mainly on the author's studies. [ABSTRACT FROM AUTHOR]

Leiomyoadenomatoid tumors of the epididymis are exceedingly rare biphasic tumors composed of an adenomatoid component in the form of gland-like structures lined by single flat or cuboidal cells admixed with smooth muscle. Radiological and gross findings cannot distinguish leiomyoadenomatoid tumors from the more common classic adenomatoid tumors or leiomyomas, and careful microscopic examination is critical in the identification of this esoteric variant. The histogenesis of this entity remains ambiguous. Common hypotheses include a collision tumor, a variant of an adenomatoid tumor with a smooth muscle component, or an adenomatoid tumor arising in the background of reactive smooth muscle hyperplasia. We present 2 cases of leiomyoadenomatoid tumors with diffuse nuclear WT1 positivity in both the adenomatoid and smooth muscle components, supporting the mesothelial origin of these tumors. [ABSTRACT FROM AUTHOR]

With the current reassessment of the phylogeny of Hamamelidaceae, the problem of revealing the apomorphies and plesiomorphies in this group arises and peculiarities of histogenesis of the reproductive structures deserve recognition. With the aim to fill in the gap in the data on fruit structure in Hamamelidaceae, we focused on investigating the processes of fruit organogenesis and histogenesis of the fruit wall in Loropetalum. The fruit of L. chinense is an almost inferior dimerous syncarpous loculicidal (dorsoventrally dehiscent) capsule with the mature fruit wall differentiated into epicarp, mesocarp and endocarp. The main tissue of the epicarp and the peripheral zone of the mesocarp are composed of thin-walled cells with scattered brachysclereids, whereas the inner zone of the mesocarp consists of fibre-like sclereids. The endocarp finishes its differentiation at the young fruit stage and is represented in mature fruit by several layers of thin-walled cells. The fruit of L. chinense represents capsules of the Forsythia type, which have not been previously described for Hamamelidaceae, and it differs from capsules of the Hamamelis type described for Hamamelis , Corylopsis and Fothergilla. The revealed characters of L. chinense fruits indicate the possibility of transformation of the explosive capsule into a pyrenarium. [ABSTRACT FROM AUTHOR]

Sebaceous carcinoma (SC) is a rare carcinoma classified as ocular or extraocular. Ocular SC is believed to arise from the meibomian glands or the glands of Zeis. However, the origin of extraocular SC is controversial because there is no evidence of carcinoma arising from pre-existing sebaceous glands. Several hypotheses about the origin of extraocular SC have been proposed, including one suggesting an origin from intraepidermal neoplastic cells. Although extraocular SCs have been shown to occasionally comprise intraepidermal neoplastic cells, no study has investigated whether intraepidermal neoplastic cells possess sebaceous differentiation. The present study analyzed the clinicopathological features of ocular and extraocular SC, with an emphasis on the presence of in situ (intraepithelial) l esions. It retrospectively reviewed the clinicopathological features of eight patients with ocular and three patients with extraocular SC (eight women and three men; median age, 72 years), respectively. In situ (intraepithelial) lesions were observed in four of the eight ocular SC cases and one of the three extraocular SC cases and an apocrine component was noted in one patient with ocular SC (seboapocrine carcinoma). In addition, immunohistochemical analyses showed that the androgen receptor (AR) was expressed in all ocular SCs and two of the three extraocular SC cases. Adipophilin expression was observed in all ocular and extraocular SC. In situ lesions of extraocular SC showed positive immunoreactivity for both AR and adipophilin. The present study is the first to demonstrate sebaceous differentiation in in situ lesions of extraocular SC. The possible origin of extraocular SC is speculated to be the progenitor cells present in the sebaceous duct or interfollicular epidermis. The results of the present study and reported cases of SC in situ indicate that extraocular SC also arises from intraepidermal neoplastic cells. [ABSTRACT FROM AUTHOR]

Introduction: Salivary gland tumors are complex and diagnosing them remains a challenge due to their varied histomorphology attributed to the ability of cell to differentiate from its cell of origin and transform into various morphological patterns. Aim: The present article is aimed at reviewing the current concepts in tumorogenesis of salivary gland lesions emphasizing on the aspect of histogenesis and morphogenesis. Materials and Method: The relevant article was collected and reviewed Discussion: The current concepts of histogenesis and morphogenesis in the development of tumor may help the pathologists to differentiate the salivary gland tumors and to diagnose at the earliest. Conclusion: Understanding the insight of histogenesis of salivary gland will help to set criterias for classification of tumors based on cell of origin and the morphological patterns. [ABSTRACT FROM AUTHOR]

Central granular cell odontogenic tumors (CGCOTs) are rare, benign, slowly growing odontogenic neoplasms. Due to their uncertain histogenesis, CGCOTs are still not included as a distinct entity in the WHO classification (2017) of odontogenic tumors. We report a case of CGCOT involving the right side of maxillary anterior region of a 39-year-old white female. Immunohistochemical staining showed that granular cells positively expressed CD68 and vimentin, and negatively expressed S-100 protein. Meanwhile, we searched PubMed, Google Scholar, and Scopus databases to summary the clinico-pathological features of 51 reported cases of CGCOT. The results showed that the granular cells of 28.6% cases were immunopositive for vimentin and CD68, and odontogenic epithelial cells were positive immunoreactivity for cytokeratin. These findings reinforced the mesenchymal origin of granular cells and the odontogenic nature of epithelium islands. [ABSTRACT FROM AUTHOR]

Purpose: Severe calcaneal malunion is a clinical conundrum for the difficulty of calcaneal reconstruction without soft tissue complications. The aim of this study is to introduce the treatment strategy and preliminary results of staged Illizarov distraction histogenesis and corrective reconstruction for severe malunion of calcaneal fractures. Methods: From June 2014 to May 2020, 14 patients with severe calcaneal malunion treated with the staged strategy were retrospectively analyzed. At the first stage, calcaneal osteotomy and external fixation with Ilizarov frame were performed. The restoration of the approximate configuration of calcaneus and the expansion of contractural soft tissue were achieved by gradual calcaneal distraction. At the second stage, corrective reconstruction was performed and autogenous iliac crest bone graft was used. Clinical and radiographic outcomes were evaluated at final follow-up. Results: The average time of Ilizarov distraction and total fixation was 21.4 days and 41.0 days at first-stage treatment. At a mean follow-up of 33.1 months, the average American Orthopaedic Foot and Ankle Society (AOFAS) ankle and hindfoot score increased significantly from 24.0 to 72.4 (p < 0.01). And the mean visual analogue scale (VAS) score had improved remarkably from 8.2 to 2.4 (p < 0.01). Radiographs showed that talocalcaneal height, calcaneal width, calcaneal tuberosity height, hindfoot alignment angle, and talar declination angle were improved to a great extent (p < 0.01). Only one patient had minor pin site infection at first-stage treatment and one got superficial wound infection after second-stage surgery. No wound dehiscence, skin necrosis, or deep infection occurred. Conclusion: Staged Ilizarov distraction histogenesis and corrective reconstruction is a safe and effective treatment strategy for reducing soft tissue complications and improving reconstruction results in surgical correction of severe calcaneal malunion. [ABSTRACT FROM AUTHOR]

Understanding how retinal progenitor cells (RPCs) give rise to the variety of neural cell types of the retina has been a question of major interest over the last few decades. While environmental cues and transcription factor networks have been shown to control specific cell fate decisions, how RPCs alter fate output over time to control proper histogenesis remains poorly understood. In recent years, the identification of "temporal identity factors (TIFs)", which control RPC competence states to ensure that the right cell types are produced at the right time, has contributed to increasing our understanding of temporal patterning in the retina. Here, we review the different TIFs identified to date in the mammalian retina and discuss the underlying mechanisms by which they are thought to operate. We conclude by speculating on how identification of temporal patterning mechanisms might support the development of new therapeutic approaches against visual impairments. [ABSTRACT FROM AUTHOR]

Evidence indicates that different pathways of malignant degeneration underlie the development of endometriosis-associated ovarian tumors of endometrioid and clear cell histotypes. The aim of this study was to compare data from patients affected by these two histotypes to investigate the hypothesis of a dichotomy in the histogenesis of these tumors. Clinical data and tumor characteristics of 48 patients who were diagnosed with either pure clear cell ovarian cancer and mixed endometrioid–clear cell ovarian cancer arising from endometriosis (ECC, n = 22) or endometriosis-associated endometrioid ovarian cancer (EAEOC, n = 26) were compared. A previous diagnosis of endometriosis was detected more frequently in the ECC group (32% vs. 4%, p = 0.01). The incidence of bilaterality was significantly higher in the EAOEC group (35% vs. 5%, p = 0.01) as well as a solid/cystic rate at gross pathology (57.7 ± 7.9% vs. 30.9 ± 7.5%, p = 0.02). Patients with ECC had a more advanced disease stage (41% vs. 15%; p = 0.04). A synchronous endometrial carcinoma was detected in 38% of EAEOC patients. A comparison of the International Federation of Gynecology and Obstetrics (FIGO) stage at diagnosis showed a significantly decreasing trend for ECC compared to EAEOC (p = 0.02). These findings support the hypothesis that the origin, clinical behavior and relationship with endometriosis might be different for these histotypes. ECC, unlike EAEOC, seems to develop within an endometriotic cyst, thus representing a window of possibility for ultrasound-based early diagnosis. [ABSTRACT FROM AUTHOR]

Background of Study: To assess the prenatal development of the human liver at gestation ages (GAs) 12-36 weeks using microscopic parameters and their correlation to predict the GA. The observation of microscopic features such as Kupffer cells (KCs), hematopoietic activity, stellate cells, glycogen granules, central vein (CV), and portal triad (PT) carries immense importance for its use in the estimation of fetal GA, detection of anatomical variations, and identification of congenital anomalies concerning branches such as anatomy, surgery, forensic sciences, radiology, pediatrics, and phytopathology. Materials and Methods: The present study was conducted in the department of anatomy on 33 normal fetuses of GA 12-36 weeks and classified them into 5 groups as A (12-16 weeks), B (17-21 weeks), C (22-26 weeks), D (27-31 weeks), and E (32-36 weeks). The general parameters were measured. Slides were prepared as per standard protocol and observed under a light microscope. Results: Microscopic observation reveals CV and PT in 15 weeks, dominant hematopoiesis till 21 weeks and then declines gradually, KC in 16 weeks, sinusoids in 19 weeks, glycogen granules deposition from 36 weeks, and hepatic lobule and portal lobule appears at 31 weeks. Conclusion: The knowledge of morphological features with respect to gestational age is a reliable reference help to prevent misdiagnosis of various pathological conditions of the liver such as cirrhosis, hepatomegaly, fetal anemia, intrauterine growth retardation, and congenital anomalies. [ABSTRACT FROM AUTHOR]

The quail (Coturnix coturnix, Linnaeus 1758), a notable model used in developmental biology, is a precocial bird species in which the processes of retinal cell differentiation and retinal histogenesis have been poorly studied. The purpose of the present research is to examine the retinogenesis in this bird species immunohistochemically and compare the results with those from previous studies in precocial and altricial birds. We found that the first PCNA-negative nuclei are detected at Stage (St) 21 in the vitreal region of the neuroblastic layer, coinciding topographically with the first αTubAc-/Tuj1-/Isl1-immunoreactive differentiating ganglion cells. At St28, the first Prox1-immunoreactive nuclei can be distinguished in the vitreal side of the neuroblastic layer (NbL), but also the first visinin-immunoreactive photoreceptors in the scleral surface. The inner plexiform layer (IPL) emerges at St32, and the outer plexiform layer (OPL) becomes visible at St35—the stage in which the first GS-immunoreactive Müller cells are distinguishable. Newly hatched animals show a well-developed stratified retina in which the PCNA-and pHisH3-immunoreactivies are absent. Therefore, retinal cell differentiation in the quail progresses in the stereotyped order conserved among vertebrates, in which ganglion cells initially appear and are followed by amacrine cells, horizontal cells, and photoreceptors. Müller glia are one of the last cell types to be born. Plexiform layers emerge following a vitreal-to-scleral gradient. Finally, our results suggest that there are no significant differences in the timing of different events involved in retinal maturation between the quail and the chicken, but the same events are delayed in an altricial bird species. [ABSTRACT FROM AUTHOR]

Abstract Background Multiple kidney tumours are frequently seen in hereditary syndromes and familial diseases. Renal collision tumours (RCT) are characterized by the simultaneous existence of different and unrelated tumour types within the same location in the kidney, forming a single, heterogenous lesion. RCT are uncommon histological entities with distinctive features. The most frequent subtypes include clear cell renal cell carcinoma (CCRCC), papillary renal cell carcinoma (PRCC), chromophobe renal cell carcinoma (CRCC), and collecting duct carcinoma (CDC). Case presentation Here, we report three sporadic cases of RCT successfully treated by nephrectomy and confirmed by histological analysis. The first case was of a 64-year-old man diagnosed with RCT composed of a stage 2 nucleolar grade 3 CCRCC and a stage 1a nucleolar grade 2 type 1 PRCC. The second case was of a 68-year-old woman diagnosed with a combined nucleolar grade 2 type 1 PRCC and an angiomyolipoma (non-assessed stage), while the third case was of a 59-year-old woman diagnosed with a combined stage 1a nucleolar grade 3 CCRCC and a stage 1b CDC. Conclusions Due to the rarity of RCT, there are no standard guidelines for their management. Hence, the prognosis is considered to be associated with the most aggressive component, possibly the tumour with the highest nucleolar grade and stage. The histogenesis of RCT remains debated, and increase in knowledge regarding this can help enable the development of targeted therapies for advanced or metastatic tumours.

Primary bone lymphoma (PBL) is a rare neoplasm of malignant lymphoid cells presenting with one or more bone lesions without nodal or other extranodal involvement. It accounts for approximately 1% of all lymphomas and 7% of malignant primary bone tumors. Diffuse large B-cell lymphoma (DLBCL), not otherwise specified (NOS) represents the predominant histological type and constitutes over 80% of all cases. PBL may occur at all ages with a typical diagnosis age of 45–60 years and a slight male predominance. Local bone pain, soft tissue edema, palpable mass and pathological fracture are the most common clinical features. Diagnosis of the disease, which is frequently delayed due to its non-specific clinical presentation, is based on the combination of clinical examination and imaging studies and confirmed by combined histopathological and immunohistochemical examination. PBL can develop in any part of the skeleton, although it occurs most commonly in the femur, humerus, tibia, spine and pelvis. The imaging appearance of PBL is highly variable and unspecific. In terms of the cell-of-origin, most cases of primary bone DLBCL (PB-DLBCL), NOS belong to the germinal center B-cell-like subtype and specifically originate from germinal center centrocytes. PB-DLBCL, NOS has been considered a distinct clinical entity based on its particular prognosis, histogenesis, gene expression and mutational profile and miRNA signature. PBL carries a favorable prognosis, especially when treated with combined chemoradiotherapy. [ABSTRACT FROM AUTHOR]

Cribriform morular thyroid carcinoma (CMTC) is a rare malignant thyroid tumor with a peculiar growth pattern secondary to permanent activation of the WNT/β-catenin pathway. CMTC may be associated with familial adenomatous polyposis or sporadic; it shares morphological features with papillary thyroid carcinoma (PTC) and was considered a variant of PTC in the 2017 WHO classification of tumors of endocrine organs. The new 5th edition of the WHO classification of endocrine and neuroendocrine tumors considered CMTC an independent thyroid neoplasm of uncertain histogenesis. A thymic/ultimobranchial pouch-related differentiation in CMTC has been recently postulated. We, however, have used the pathological and immunohistochemical features of this case of CMTC with 2 novel oncogenic somatic variants (c.3428_3429insA, p.(Tyr1143Ter) and c.3565del, p. (Ser1189Hisfs*76) of the APC gene to propose an origin from follicular cells (or their endodermal precursors). As usual in CMTC, the morular component of this tumor was positive for CDX2. Given the fact that WNT/β-catenin signaling, through CDX2, activates large intestine and small intestine gene expression, we postulate that in CMTC, the tumor cells have their terminal differentiation blocked, thus showing a peculiar primitive endodermal (intestinal-like) phenotype negative for sodium-iodide symporter, thyroperoxidase, and thyroglobulin. Establishing the histogenesis of CMTC is very relevant for the development of appropriate therapies of redifferentiation, particularly in patients where the tumor cannot be controlled by surgery. [ABSTRACT FROM AUTHOR]

Introduction: Intracranial germ cell tumor (iGCT) is a rare disorder and often occurs during childhood and adolescence. iGCTs are frequently localized in pineal region and hypothalamic–neurohypophyseal axis (HNA). In spite of well-established clinical and pathological entity, histogenesis of iGCTs remains unsettled. Current theories of histogenesis of iGCTs include germ cell theory (from primordial germ cells (PGCs) of aberrant migration) and stem cell theory (transformed embryonic stem (ES) cells). In order to comprehend the histogenesis, we revisit the origin, migration, and fate of the human PGCs, and their transformation processes to iGCT. Discussion: In "germ cell theory," transformation of ectopic PGCs to iGCT is complex and involves multiple transcription factors. Germinoma is derived from ectopic PGCs and is considered a prototype of all GCTs. Non-germinomatous germ cell tumors (NGGCTs) develop from more differentiated counterparts of embryonic and extra-embryonic tissues. However, there is a distinct genomic/epigenomic landscape between germinoma and NGGCT. ES cells transformed from ectopic PGCs through molecular dysregulation or de-differentiation may become the source of iGCT. "Stem cell theory" is transformation of endogenous ES cells or primitive neural stem cell to iGCTs. It supports histological diversity of NGGCTs because of ES cell's pluripotency. However, neural stem cells are abundantly present along the subependymal zone; therefore, it does not explain why iGCTs almost exclusively occur in pineal and HNA locations. Also, the vast difference of methylation status between germinoma and NGGCT makes it difficult to theorize all iGCTs derive from the common cellular linage. Conclusion: Transformation of PGCs to ES cells is the most logical mechanism for histogenesis of iGCT. However, its detail remains an enigma and needs further investigations. [ABSTRACT FROM AUTHOR]

More than 50% cells isolated from the endometrial cavity scraping and the myometrium of the rudimentary horn of an underdeveloped uterus removed from a patient with uterine aplasia and maintained under culturing conditions normal for mesenchymal stem cells (MSC) expressed embryonic transcription factors Oct4 and Nanog, embryonic cell membrane sialyl glycolipid SSEA4, and MSC markers. After 2-3 passages, the cells lost the expression of the early embryogenesis markers, but retained MSC markers. The presence of dormant stem cells in the underdeveloped endometrium and in the uterus indicates that this tissue has a regenerative potential that can be activated and used for completion of organ morphogenesis. This task requires the development of methods of early diagnosis of morphogenesis impairment and tools for safe reactivation of the ontogenesis. [ABSTRACT FROM AUTHOR]

Background: Dermatofibromas (DFs) are benign fibrohistiocytic lesions that usually do not express CD34 protein. This study aimed to analyze the literature concerning the immunohistological and ultrastructural features of DFs. It also related these features to the histogenesis of these lesions. Methods: This study included a PubMed literature search for studies addressing the clinicopathological, ultrastructural, and immunohistochemical features of DFs. It also presented some current cases of CD34-negative DFs and a subset of these lesions with aberrant expression of this protein. Results: Analysis of the PubMed literature revealed that DFs with an aberrant expression of CD34 are rare tumors that commonly affect the extremities of adult females. Separating these tumors from dermatofibrosarcoma protuberans (DFSP, CD34-positive tumors) requires using a large panel of immunostains. Ultrastructurally, DFs are composed of diverse cell types, including cells with histiocytic, myofibroblastic, and fibroblastic features. An analysis of the DFs described by this study revealed that cases with an aberrant expression of CD34 protein had slightly high mean age and male sex predominance when compared to CD34-negative cases. The former commonly affected the extremities. There was no evidence of local recurrence or distant metastasis on follow-up. Conclusions: DFs have the potential to express CD34 protein, defining a rare aberrant phenotype, which was not associated with any differences in the outcome as compared to CD34-negative DFs. [ABSTRACT FROM AUTHOR]

Purpose of Review: The purpose of review is to provide a comprehensive review of the literature focusing on the recent advances in the diagnosis, molecular underpinning, and targeted therapy of olfactory neuroblastoma (ONB). Recent Findings: Studies focused on the molecular fingerprinting of ONB are critical to engage new promising treatment strategies. Molecular-based subtype classifications have been proposed (basal-like ONB and neural-like ONB) but are not widely used. The rationale for implementation of DNA methylation analysis and IDH2 sequencing in routine work-up for ONB is gaining recognition. Expression of somatostatin receptors (SSTR) in ONB open new avenues for both, diagnostic (especially metastatic disease) and new treatment protocols with somatostatin analogs. Olfactory carcinoma is proposed as a unifying diagnostic terminology pertinent to epithelial divergent differentiation in olfactory neuroblastoma. Summary: Molecular (genetic and epigenetic) efforts on olfactory neuroblastoma are promising; however further refinement is needed for employment of these biomarkers as clinical standard of care. Ongoing and future multi-institutional collaborative studies will contribute to further understanding of ONB biology and aid the development of targeted treatments for this disease. [ABSTRACT FROM AUTHOR]

In this review, the concept of fruit morphogenesis is treated in the context of implementation of the evo-devo approach in carpology. A new viewpoint on the fruit morphogenesis is proposed and justified, comprising the pre-anthetic, as well as post-anthetic periods of fruit development, id est, development of the gynoecium, and development of the fruit itself. It is proposed to recognize ontogenetical (individual) and evolutionary (historical) aspects of fruit morphogenesis, the first of them we can study directly, while the second aspect can be only hypothesized or treated as a theoretical model of fruit evolution in consequence of some presumed changes in the individual fruit morphogenesis. In this article these aspects are named as "ontomorphogenesis" and "phylomorphogenesis" of the fruit, correspondingly. Our concept of ontomorphogenesis of the fruit involves four components that could not be brought together, such as changes in the morphological structure of the gynoecium, abscission of the extragynecial floral parts and the style, histogenesis of the fruit wall and other fruit parts, and terminal stages of the fruit morphogenesis (dehiscence, splitting, or abscission). The current state of studies of these components in the individual and evolutionary contexts is discussed. By examining the patterns of fruit evolution, we should consider factors acting at both the post-anthetic and pre-anthetic periods of fruit ontomorphogenesis.

Published histologic studies of the hilar plate or entire biliary remnant at the time of Kasai portoenterostomy (KHPE) have not provided deep insight into the pathogenesis of biliary atresia, relation to age at surgery, prognosis or the basis for successful drainage. We report detailed histologic findings in 172 centrally reviewed biliary remnants with an average of 6 sections per subject. Active lesions were classified as either necroinflammatory (rare/clustered in a few subjects) or active concentric fibroplasia with or without inflammation (common). Inactive lesions showed bland replacement by collagen and fibrous cords with little or no inflammation. Heterogeneity was common within a given remnant; however, relatively homogenous histologic patterns, defined as 3 or more inactive or active levels in the hepatic ducts levels, characterized most remnants. Homogeneity did not correlate with age at KHPE, presence/absence of congenital anomalies at laparotomy indicative of heterotaxy and outcome. Remnants from youngest subjects were more likely than older subjects to be homogenously inactive suggesting significantly earlier onset in the youngest subset. Conversely remnants from the oldest subjects were often homogenously active suggesting later onset or slower progression. More data are needed in remnants from subjects

Composite mantle cell lymphoma and classical Hodgkin lymphoma is very rare and the actual origin of it is still unclear. Here we reported a new case of composite mantle cell lymphoma and classical Hodgkin lymphoma and analyzed its molecular changes. Eight mutations were identified in its Hodgkin component through next-generation sequencing. In addition, we reviewed the published cases of composite mantle cell lymphoma and classical Hodgkin lymphoma and summarized the molecular changes of reported cases as well as the current case to explore the possible pathway of histogenesis.

Basándonos en los antecedentes de estudios en el Sistema Nervioso Central (SNC) normal y patológico, realizados con técnicas argénticas y de inmunornarcación con peroxidasa-antiperoxidasa (PAP) para proteína gliofibrilar ácida (GFAP), nos propusimos comparar blastornas gliales con ambos métodos y extraer conclusiones. Ya que las sales de plata son importantes marcadores de estas células, analizamos si con ambas técnicas se logran imágenes semejantes, si son específicas para marcar gliofibrillas, y si alguno de los métodos marca mejor las células más anaplásicas. De estas conclusiones se desprende la necesidad de comparar las Clasificaciones de los Tumores Nerviosos, y en especial la de Del Río Hortega-Polak con respecto a otras existentes de difusión universal. Resumen El OBJETIVO de nuestro trabajo es comparar 2 métodos diagnósticos, y demostrar las semejanzas de las distintas Clasificaciones de los Tumores Gliales del Sistema Nervioso Central. Se realizaron técnicas de inmunomarcación para proteína gliotibrilar ácida (GFAP), e impregnaciones argénticas especiales para confrontar los hallazgos según las últimas Interpretaciones histogenéticas. Estudiamos 95 Gliomas con hematoxilina-eosina y técnicas argénticas, y en 58 casos tomados al azar realizamos además la técnica para GFAP. Con ambos métodos obtuvimos resultados iguales en el diagnóstico de tumores gliales cuyas células poseen gliofibrillas: Glioepiteliomas (Ependimomas). UI iuhlastornas, Astroblastornas y Astrocitumas. En los Oligodendrogliomas cuyas células no poseen gliofibrillas pero sí microtúhulos, las técnicas argénticas marcaron estas células y sus prolongaciones, no así la técnica para GFAP. Hay semejanzas al comparar la Clasificación de Del Río Hortcga-Polak con la de la OMS y la de otros autores, en lo relirentc a los Gliomas. Sólo hay diferencias en la nomenclatura de algunos tumores o en su interpretación histogenética, que no son sustanciales y están limitados al "Espongio-blastoma Polar' y al "Gliosarcoma". Por lo tanto, creemos que la revalorización de la Clasificación de Del Río l-lortega-Polak estújustíficada.