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We report a case of unilateral polycystic disease of the parotid gland. Only eight cases of this disease have previously been published in the English language literature, and seven of them were bilateral. Thus, we are reporting the second case of unilateral involvement. The disease is apparently limited to the parotid gland and to women. Clinically, a fluctuating, long-standing, nontender parotid gland swelling is usually noticed in adulthood. Histologically, there are numerous epithelial-lined cysts, which appear to be derived from intercalated ducts. This disease probably represents a developmental condition. [ABSTRACT FROM AUTHOR]

Investigates the possibility that gastric mucosa-associated lymphoid tissue (MALT) is acquired in `Helicobacter pylori' infection and that this provides the necessary background in which MALT lymphoma might develop. Patients and methods; Results;Discussion.

Primary cutaneous anaplastic large cell lymphoma (ALCL) is the second most common cutaneous T-cell lymphoma after mycosis fungoides and belongs to the spectrum of cutaneous CD30+ T-cell lymphoproliferative disorders. Although primary cutaneous ALCL usually presents as a localized nodule or papule with or without ulceration, multifocal lesions may occur in up to 20% of cases. Histologically, primary cutaneous ALCL consists of a diffuse dermal infiltrate of medium to large anaplastic/pleomorphic cells with abundant amphophilic-to-eosinophilic cytoplasm, horseshoe-shaped nuclei, strong and diffuse expression of CD30, and with focal or no epidermotropism. The neoplastic infiltrate may show angiocentric distribution and may extend to the subcutis. Patients with localized or multifocal disease have a similar prognosis with a 10-year overall survival rate of 90%. Approximately 30% of primary cutaneous ALCLs harbor a DUSP22 (6p25.3) gene rearrangement that results in decreased expression of this dual-specific phosphatase, decreased STAT3 activation, and decreased activity of immune and autoimmune-mediated mechanisms regulated by T-cells.

In 1852, Owen, a prominent British anatomist, described the parathyroid glands. While dissecting a rhinoceros, he noted a small compact yellow body, attached to the thyroid. Virchow and later Remak described the human parathyroids around 1960, but credit for the first complete description goes to the Sandström in 1980. More than a decade later Gley, showed that it was the removal of the parathyroids that accounted for the tetany that followed thyroidectomy. The association of parathyroid pathology and skeletal abnormalities was made in 1914 by Erdheim and Schlagenhaufer, and Mandl, was the first surgeon to successfully treat a case of osteitis fibrosa by surgical removal of a parathyroid adenoma in 1925. The most extensive work on hyperparathyroidism was done in the 1930s by Albright form Boston, who described parathyroid hyperplasia, and differentiated between primary, secondary and tertiary hyperparathyroidism. Progresses in anatomy, physiology and surgery of the parathyroid glands, have contributed to various effective modalities of diagnosis and treatment., (Copyright: © 2022 Permanyer.)

Immunohistochemistry is an extraordinary and extensively used technique whereby antibodies are used to detect antigens in cells within a tissue section. It has numerous applications in medicine, particularly in cancer diagnosis. It was Albert Hewett Coons, Hugh J Creech, Norman Jones, and Ernst Berliner who conceptualized and first implemented the procedure of immunofluorescence in 1941. They used fluorescein isothiocyanate (FITC)-labelled antibodies to localize pneumococcal antigens in infected tissues. Since then, with improvement and development of protein conjugation, enzyme labels have been introduced, such as peroxidase and alkaline phosphatase. The history of immunohistochemistry (IHC) combines physiology, immunology, biochemistry, and the work of various Nobel Prize laureates. From von Behring who was awarded de first Nobel Prize in 1901 for his work on serum therapy to the 1984 Nobel Prize for the discovery of monoclonal antibodies by Milstein, Kohler, and Jerne, IHC is a story of cooperation and collaboration which led to the development of this magnificent technique that is used daily in anatomical pathology laboratories worldwide., (© 2022. Springer Science+Business Media, LLC, part of Springer Nature.)

The case An 18-year-old male presented with a one-month history of a nonpainful right testicular enlargement. He had no family history of neoplasia, nor any relevant past medical history. The physical examination was only remarkable for an enlarged right testicle. A testicular ultrasound revealed a 2.5-cm tumor, and serum tumor markers revealed an elevated β-human chorionic gonadotropin (β-HCG), 22 mUI/L (normal, < 0.06 mUI/L); elevated alpha-fetoprotein (AFP), 329 ng/mL (normal, 0-9 ng/mL); and normal lactate dehydrogenase (LDH), 135 /L (normal, 179 U/L). A right radical inguinal orchiectomy was performed. Pathological examination revealed a 2.4 cm by 2 cm embryonal carcinoma with tumor invasion into the tunica albuginea. Postsurgical tumor markers obtained 3 weeks after orchiectomy were β-hCG, 100.5 mUI/L (normal, < 0.06 mUI/L); AFP, 1075 ng/mL (normal, 0-9 ng/mL); and LDH, 180 U/L (normal, 179 U/L). A chest, abdomen, and pelvis CT scan showed a 2.7-cm retroperitoneal lymph node enlargement, without visceral metastasis. Given the presence of node-positive disease with S2 serum markers, the diagnosis of a stage IIIB intermediate risk nonseminomatous germ cell tumor (NSGCT) was determined, and the patient underwent sperm banking. The patient was started on chemotherapy with 4 cycles of BEP (bleomycin, etoposide, and cisplatin), with a favorable tumor marker decline according to the Gustave-Roussy nomogram. After completion of the fourth chemotherapy cycle, serum tumor markers were negative, and 8 weeks after chemotherapy, the follow-up CT showed a 1.6-cm residual retroperitoneal lymph node conglomerate.

Breast implant-associated anaplastic large cell lymphoma (ALCL) is a distinctive type of T-cell lymphoma that arises around textured-surface breast implants. In a subset of patients, this disease can involve surrounding tissues, spread to regional lymph nodes, and rarely metastasize to distant sites. The aim of this study was to assess sequential pathologic specimens from patients with breast implant-associated ALCL to better understand the natural history of early-stage disease. To achieve this goal, we searched our files for patients who had breast implant-associated ALCL and who had undergone earlier surgical intervention with assessment of biopsy or cytologic specimens. We then focused on the patient subset in whom a definitive diagnosis was not established, and patients did not receive current standard-of-care therapy at that time. We identified a study group of ten patients with breast implant-associated ALCL in whom pathologic specimens were collected 0.5 to 4 years before a definitive diagnosis was established. A comparison of these serial biopsy specimens showed persistent disease without change in pathologic stage in three patients, progression in five patients, and persistence versus progression in two patients. Eventually, six patients underwent implant removal with complete capsulectomy and four underwent partial capsulectomy. Seven patients also received chemotherapy because of invasive disease, three of whom also received radiation therapy, two brentuximab vedotin after chemotherapy failure, and one allogeneic stem cell transplant. Eight patients achieved complete remission and two had partial remission after definitive therapy. At time of last follow-up, six patients were alive without disease, one had evidence of disease, one died of disease, and two patients died of unrelated cancers. In summary, this analysis of sequential specimens from patients with breast implant-associated ALCL suggests these neoplasms persist or progress over time if not treated with standard-of-care therapy., (© 2021. The Author(s), under exclusive licence to United States & Canadian Academy of Pathology.)

Anaplastic large cell lymphoma (ALCL) is a subtype of CD30+ large T-cell lymphoma (TCL) that comprises ~2% of all adult non-Hodgkin lymphomas. Based on the presence/absence of the rearrangement and expression of anaplastic lymphoma kinase (ALK), ALCL is divided into ALK+ and ALK-, and both differ clinically and prognostically. This review focuses on the historical points, clinical features, histopathology, differential diagnosis, and relevant cytogenetic and molecular alterations of ALK- ALCL and its subtypes: systemic, primary cutaneous (pc-ALCL), and breast implant-associated (BIA-ALCL) . Recent studies have identified recurrent genetic alterations in this TCL. In systemic ALK- ALCL, rearrangements in DUSP22 and TP63 are detected in 30% and 8% of cases, respectively, while the remaining cases are negative for these rearrangements. A similar distribution of these rearrangements is seen in pc-ALCL, whereas none have been detected in BIA-ALCL. Additionally, systemic ALK- ALCL-apart from DUSP22 -rearranged cases-harbors JAK1 and/or STAT3 mutations that result in the activation of the JAK/STAT signaling pathway. The JAK1/3 and STAT3 mutations have also been identified in BIA-ALCL but not in pc-ALCL. Although the pathogenesis of these alterations is not fully understood, most of them have prognostic value and open the door to the use of potential targeted therapies for this subtype of TCL.

Carl von Rokitansky was one of the most important figures in pathological anatomy, and was largely responsible for the resurgence of Vienna as the great medical center of the world in the mid-19 th century. He was born in current Hradec Králové, studied medicine in Prague and Vienna and was graduated in 1828. He was greatly influenced by the anatomy, embryology and pathology studies of Andral, Lobstein and Meckel. At the Vienna School, he was Johann Wagner pathological anatomy assistant and became a pathology professor, where he remained until four years before his death. Rokitansky emphasized the importance of correlating patient symptoms with postmortem changes. It is possible that he had access to between 1,500 and 1,800 cadavers annually to be able to perform 30,000 necropsies; in addition, he reviewed several thousand more autopsies. In Handbuch der pathologischen Anatomie, published between 1842 and 1846, he made numerous descriptions: lobar and lobular pneumonia, endocarditis, diseases of the arteries, cysts in several viscera, various neoplasms and acute yellow atrophy of the liver. With his brilliant work on gross pathology, Rokitansky established the nosological classification of diseases, for which Virchow named him "the Lineé of pathological anatomy"., Carl von Rokitansky fue una de las figuras más importantes en la anatomía patológica y el responsable, en parte, del renacimiento de Viena como centro de la medicina a mediados del siglo XIX. Nació en la actual Hradec Králové, estudió medicina en Praga y Viena y se graduó en 1828. Tuvo gran influencia de los estudios de anatomía, embriología y patología de Andral, Lobstein y Meckel. En la escuela de Viena fue asistente de anatomía patológica de Johann Wagner y se convirtió en profesor de anatomía patológica, donde permaneció hasta cuatro años antes de su muerte. Rokitansky hizo énfasis en correlacionar la sintomatología del enfermo con los cambios post mortem. Es posible que haya tenido acceso a entre 1500 y 1800 cadáveres al año para que pudiera realizar 30 000 necropsias; además, revisó varios miles más de autopsias. En Handbuch der Pathologischen Anatomie, publicado entre 1842 y 1846, realizó numerosas descripciones: de la neumonía lobular y lobular, endocarditis, enfermedades de las arterias, quistes en varias vísceras, diversas neoplasias y de la atrofia aguda amarilla del hígado. Con su brillante labor de patología macroscópica, Rokitansky estableció la clasificación nosológica de las enfermedades, por lo cual Virchow lo llamó “el Linneo de la anatomía patológica”., (Copyright: © 2020 Permanyer.)

Solid pseudopapillary neoplasm of the pancreas is a rare tumor of uncertain histogenesis, described separately by Gruber and Frantz, that accounts for between approximately 1% and 3% of pancreatic neoplasms. It is characterized by a cystic and solid pattern of growth patterns with formation of pseudopapillae. It occurs primarily in young women, although cases in children and older patients and men have been reported. The tumor is of low-grade malignant potential, as the majority of the cases are cured by simple but complete surgical resection. Knowledge of the unique morphologic characteristics of this neoplasm is essential for the correct diagnosis. We review herein the pathologic and immunohistochemical features of this neoplasm and its differential diagnosis with other pancreatic tumors., (Copyright © 2019 Sociedad Española de Anatomía Patológica. Publicado por Elsevier España, S.L.U. All rights reserved.)

Background: Diffuse large B-cell lymphoma (DLBCL) is classified into germinal center-like (GCB) and non-germinal center-like (non-GCB) cell-of-origin groups, entities driven by different oncogenic pathways with different clinical outcomes. DLBCL classification by immunohistochemistry (IHC)-based decision tree algorithms is a simpler reported technique than gene expression profiling (GEP). There is a significant discrepancy between IHC-decision tree algorithms when they are compared to GEP., Methods: To address these inconsistencies, we applied the machine learning approach considering the same combinations of antibodies as in IHC-decision tree algorithms. Immunohistochemistry data from a public DLBCL database was used to perform comparisons among IHC-decision tree algorithms, and the machine learning structures based on Bayesian, Bayesian simple, Naïve Bayesian, artificial neural networks, and support vector machine to show the best diagnostic model. We implemented the linear discriminant analysis over the complete database, detecting a higher influence of BCL6 antibody for GCB classification and MUM1 for non-GCB classification., Results: The classifier with the highest metrics was the four antibody-based Perfecto-Villela (PV) algorithm with 0.94 accuracy, 0.93 specificity, and 0.95 sensitivity, with a perfect agreement with GEP (κ = 0.88, P < 0.001). After training, a sample of 49 Mexican-mestizo DLBCL patient data was classified by COO for the first time in a testing trial., Conclusions: Harnessing all the available immunohistochemical data without reliance on the order of examination or cut-off value, we conclude that our PV machine learning algorithm outperforms Hans and other IHC-decision tree algorithms currently in use and represents an affordable and time-saving alternative for DLBCL cell-of-origin identification.

Hematoxylin is a basic dye derived from the heartwood of Palo de Campeche ( Haematoxylum campechianum), the logwood tree native to Mexico and Central America. Haematoxylum means "bloodwood" in reference to its dark-red heartwood and campechianum refers to its site of origin, the coastal city of Campeche on the Yucatan Peninsula, Mexico. Hematoxylin is colorless but it turns into the color dye hematein after oxidation (ripening). The dyeing property of logwood was well-known to the natives of the Yucatan Peninsula before the arrival of the Spaniards who brought it to Europe shortly after the discovery of the Americas. An important trade soon developed related to growing and preparing hematoxylin for dyeing fabrics. Pirates discovered that one shipload of logwood was equivalent to a year's value from any other cargo, and by 1563, more than 400 pirate vessels wandered the Atlantic Ocean and attacked Spanish galleons transporting gold, silver, and logwood from the Americas to Europe. Hematoxylin and eosin is a staining method that dates back to the late 19th century. In 1865 and 1891, Böhmer and Meyer, respectively, first used hematoxylin in combination with a mordant (alum). Later, with the use of anilines by Ehrlich, the repertoire of stains expanded rapidly resulting in the microscopic descriptions of multiple diseases that were defined by their stainable features. Today hematoxylin, along with eosin, remains the most popular stain in histology.

Introduction and Objective: Granular cell tumour (GCT) is a benign neoplasm of neural/schwannian origin, usually presenting as a single asymptomatic lesion, mainly located in the dermis and subcutaneous tissue or submucosa, although multiple tumours may occur. Microscopically, GCTs are composed of large cells with abundant eosinophilic, granular cytoplasm arranged in sheets, nests, cords or trabeculae. Based on the cytological characteristics and the presence of necrosis, three types are recognized: benign, atypical and malignant. We aim to present the cytological and immunohistochemical characteristics of 12 granular cell tumours., Materials and Methods: 12 cases of GCT were selected from the consultation files of one of the authors (COH) The paraffin embedded tissue was processed for immunostaining with S-100 protein, calretinin, CD68, α-inhibin, PGP9.5, CD57 (Leu7), CD63 (NKI / C3), Gap43 (growth-associated protein-43), SOX10, TFE-3 and Ki-67., Results and Conclusions: 6 male and 6 female patients, with an average age of 40, made up the study group. The most frequent location for the tumours was in the subcutaneous soft tissues of the arms. There were no malignant cases. All tumours were positive for S-100, CD57, SOX10, calretinin, CD68, PGP9.5, α-inhibin and TFE-3, with a low Ki-67 (1-5%). Additionally, we reported, for the first time, the positive immunoreaction to Gap43 (growth-associated protein-43) in GCT., (Copyright © 2018 Sociedad Española de Anatomía Patológica. Publicado por Elsevier España, S.L.U. All rights reserved.)

Myopericytoma is a soft-tissue tumor of perivascular cells (pericytes). It is slow-growing, usually asymptomatic, and generally benign, although a malignant variant has been described. The etiology is unknown, but it has been associated with local trauma. The most common location is on the distal extremities. Histologically, it is characterized by a well-circumscribed, non-encapsulated proliferation of spindle shaped cells similar to myofibroblasts with oval nuclei and eosinophilic cytoplasm, arranged in perivascular concentric rings. There are few mitoses and no necrosis is reported. The immunohistochemical analysis is positive for smooth muscle actin and negative or weakly positive for desmin. A low Ki-67 proliferation index is typical. Treatment is surgical excision with free margins. Recurrences after adequate excision are uncommon. We describe a 48-year-old woman with a myopericytoma in an unusual location (next to the inner corner of her left eye) who was treated with surgical excision; there has been no recurrence after 5 years of follow up.

The histopathological diagnosis of dermal-based lymphoid infiltrates and proliferations is often challenging due to the vast list of biologically diverse entities that archetypally or occasionally center in the mid-dermis, especially because significant overlap exists in their clinical, histopathologic, and immunophenotypic features. The differential diagnosis includes reactive infiltrates in common and rare inflammatory dermatoses, benign conditions that may mimic lymphoid neoplasms (pseudolymphomas), and true clonal proliferations arising either primarily in the skin or rarely in extracutaneous tissues with secondary cutaneous dissemination. While numerous histopathological and immunophenotypic features have been reported to support a definitive diagnosis, no single ancillary test is sufficient for their distinction. Therefore, in this review we advocate a stepped histopathological approach for dermalbased lymphoid infiltrations, employing as key elements the general lymphocytic composition (relative B- versus T-cell ratio), coupled with the predominant cytomorphology (cell size) present. Following this strategy, the relative incidence of cutaneous involvement by each disease should always be considered, as well as the notion that a definitive diagnosis must be founded on a multiparameter approach integrating all clinical, histopathologic, immunophenotypic, and-in selected cases-molecular features., (©2018 Frontline Medical Communications.)

Anaplastic lymphoma kinase-positive (ALK+) anaplastic large-cell lymphoma (ALCL) is characterized by expression of oncogenic ALK fusion proteins due to the translocation t(2;5)(p23;q35) or variants. Although genotypically a T-cell lymphoma, ALK+ ALCL cells frequently show loss of T-cell-specific surface antigens and expression of monocytic markers. C/EBPβ, a transcription factor constitutively overexpressed in ALK+ ALCL cells, has been shown to play an important role in the activation and differentiation of macrophages and is furthermore capable of transdifferentiating B-cell and T-cell progenitors to macrophages in vitro. To analyze the role of C/EBPβ for the unusual phenotype of ALK+ ALCL cells, C/EBPβ was knocked down by RNA interference in two ALK+ ALCL cell lines, and surface antigen expression profiles of these cell lines were generated using a Human Cell Surface Marker Screening Panel (BD Biosciences). Interesting candidate antigens were further analyzed by immunohistochemistry in primary ALCL ALK+ and ALK- cases. Antigen expression profiling revealed marked changes in the expression of the activation markers CD25, CD30, CD98, CD147, and CD227 after C/EBPβ knockdown. Immunohistochemical analysis confirmed a strong, membranous CD147 (EMMPRIN) expression in ALK+ ALCL cases. In contrast, ALK- ALCL cases showed a weaker CD147 expression. CD274 or PD-L1, an immune inhibitory receptor ligand, was downregulated after C/EBPβ knockdown. PD-L1 also showed stronger expression in ALK+ ALCL compared with ALK- ALCL, suggesting an additional role of C/EBPβ in ALK+ ALCL in generating an immunosuppressive environment. Finally, no expression changes of T-cell or monocytic markers were detected. In conclusion, surface antigen expression profiling demonstrates that C/EBPβ plays a critical role in the activation state of ALK+ ALCL cells and reveals CD147 and PD-L1 as important downstream targets. The multiple roles of CD147 in migration, adhesion, and invasion, as well as T-cell activation and proliferation suggest its involvement in the pathogenesis of ALCL.

Context: - Colors are important to all living organisms because they are crucial for camouflage and protection, metabolism, sexual behavior, and communication. Human organs obviously have color, but the underlying biologic processes that dictate the specific colors of organs and tissues are not completely understood. A literature search on the determinants of color in human organs yielded scant information., Objectives: - To address 2 specific questions: (1) why do human organs have color, and (2) what gives normal and pathologic tissues their distinctive colors?, Data Sources: - Endogenous colors are the result of complex biochemical reactions that produce biologic pigments: red-brown cytochromes and porphyrins (blood, liver, spleen, kidneys, striated muscle), brown-black melanins (skin, appendages, brain nuclei), dark-brown lipochromes (aging organs), and colors that result from tissue structure (tendons, aponeurosis, muscles). Yellow-orange carotenes that deposit in lipid-rich tissues are only produced by plants and are acquired from the diet. However, there is lack of information about the cause of color in other organs, such as the gray and white matter, neuroendocrine organs, and white tissues (epithelia, soft tissues). Neoplastic tissues usually retain the color of their nonneoplastic counterpart., Conclusions: - Most available information on the function of pigments comes from studies in plants, microorganisms, cephalopods, and vertebrates, not humans. Biologic pigments have antioxidant and cytoprotective properties and should be considered as potential future therapies for disease and cancer. We discuss the bioproducts that may be responsible for organ coloration and invite pathologists and pathology residents to look at a "routine grossing day" with a different perspective.

Introduction: Castleman disease (CD) is a rare lymphoproliferative that comprises two distinct clinical subtypes (unicentric and multicentric) and has two basic histopathology patterns that are hyaline-vascular (HV) and plasma-cell (PC) type. Some cases of multicentric PC disease are associated with HHV-8 infection., Objective: To present the histopathologic and immunohistochemical characteristics of 39 cases of CD., Methods: A review of cases with the diagnosis CD from the files of the Department of Pathology of the ABC Medical Centre in Mexico City was performed. Thirty-nine cases of CD were identified, and a detailed paraffin immunophenotypic study of 9 of them was completed using desmin, cytokeratin OSCAR (CO) and Epidermal growth factor receptor (EGFR), to evaluate the dendritic cell population., Results and Conclusions: Of the 39 cases of CD, 24 were HV and 15 CP. All HV cases were unicentric and only one case of CP was multicentric. The most frequent localization in both subtypes was in lymph nodes; 21/24 cases in HV and 15 cases of CP. All cases were immunostained with CD20 that was expressed in the germinal centers (CGs), CD3 in the paracortical zone, and CD21 in follicular dendritic cells (CDF) within CGs, with expansion towards the area of the hyperplastic mantle zone (only in the HV variant). One case of CD CP was positive for HHV-8. Of the nine cases (6 HV and 3 PC cases) that were detailed with IHC, we found EGFR expression in FDC in all but one of the 9 cases studied and desmin was positive in fibroblastic reticulum cells (FRC) in all, but one of the cases of CD. CO was positive FRC in 3 of 6 cases of HV type and all (3) of the PC type. Clinical, histopathological and HIV and HHV-8 status markers, allow for the classification of CD into groups with markedly different outcomes and disease associations., (Copyright: © 2017 SecretarÍa de Salud)

A diagnostic approach of myeloproliferative neoplasms, according to the 2008 WHO classification system for hematological malignancies, has to consider clinical, molecular, and cytogenetic information as well as bone marrow histology. A diagnosis of chronic myeloid leukemia requires the presence of BCR-ABL-1, and the Philadelphia chromosome-negative (Ph-1-negative) myeloproliferative neoplasms constitute three main subtypes, including primary myelofibrosis, polycythemia rubra vera, and essential thrombocythemia. These three Ph-1-negative myeloproliferative neoplasms share many pathogenic characteristic such as JAK2 mutations; however, they differ in prognosis, progression to myelofibrosis, and risk of leukemic transformation. There are currently various major points of interest in bone marrow examination in myeloproliferative neoplasms. One is the morphology of megakaryocytes, which are the hallmark of Ph-1-negative myeloproliferative neoplasms and play a crucial role in separating the different subtypes of myeloproliferative neoplasms. Another is reticulin fibrosis or collagen fibrosis, which may only be detected on a bone marrow biopsy specimen by reticulin and trichrome stains, respectively, and immunohistochemistry and certain molecular techniques may be applied in bone marrow biopsies as supporting evidence of certain features of myeloproliferative neoplasms.

Jacob Henle was a great German anatomist and one of the most important histologists of all times. One of the most commonly used eponymous terms in renal histology is the loop of Henle, but many other anatomical and pathological findings are associated with his name. During his stay in Zurich he fell in love with Elise Egolff who worked as a maid and seamstress in the house of one of his friends. No one could ever imagine how the wide social chasm that separated the servant-girl and the professor could be bridged. Henle arranged for his sister Marie to educate Elise and give her social polish. In a short time Elise was transformed into a lady of the world. A year and a half later Jacob and Elise were married. This episode inspired the novelist Auerbach to write the novel "The Professor's Wife", and the play "Pygmalion" by George B Shaw.

Introduction: Perineurioma is an infrequent and benign cutaneous neoplasm characterized by proliferation of perineurial cells. It is classified into two main types: intraneural and the extraneural or soft tissue perineurioma, in which the sclerosing variant is included. Sclerosing perineurioma is more frequently found on acral skin. Clinically, they are well-circumscribed,skin colored, nodular tumors., Objective: Describe and communicate clinicopathologic findings from a case series of sclerosing acral perineurioma., Material and Methods: This is a clinical, morphological and immunohistologic case study of eight patients with the diagnosis of sclerosing perineurioma., Results: It included five men and five women, with ages ranging between nine and 66 years. All of them had lesion on acral skin. At microscopy study, the lesions showed a proliferation of epithelioid and spindle-shaped perineurial cells, arranged in small aggregates and short fascicles between thickened collagen bundles. Immunohistochemistry studies revealed that the proliferating cells expressed EMA, Claudin-1 and Glut-1, and were negative for S-100 protein., Conclusions: It is important to report these infrequent skin tumors, so they can be taken into account in the differential diagnoses of acral lesions.

Introduction: Pseudolymphomatous folliculitis (PLF) is a rare benign cutaneous lymphoid hyperplasia that most commonly occurs in the facial region as a dome-shaped or flat elevated nodule., Materials and Methods: We studied the clinicopathologic and immunohistochemical characteristics of 19 cases of PLF., Results: The patients comprised 11 females and eight men (mean age 44.9; age range 9-77 years). All cases were solitary except one case with multiple lesions. The lesions were located in the facial region except one that was located in the back. Histologically, there was a diffuse or nodular lymphoid infiltrate with hyperplastic and distorted hair follicles and occasionally enlarged eccrine units with a clear nuclear morphology. Immunohistologically, three cases showed predominantly B-cells, eight cases predominantly B-cells with numerous T-cells, six cases predominantly T-cells with numerous B-cells, and two cases predominantly T-cells. All lesions showed increased numbers of perifollicular dendritic cells expressing anti-S-100 protein and CD1a., Discussion: PLF is a rare, benign, cutaneous lymphoid hyperplasia that may resemble cutaneous lymphoma. It has characteristic clinical and pathologic features showing abundant periadnexal S-100/CD1a -positive dendritic cells with dilated and activated pilosebaceous units. The lesion may resolve with complete excision or present spontaneous regression.

Hybrid schwannoma/perineurioma is a recently characterized benign nerve sheath tumor, most commonly affecting the lower limb and limb girdle. Hybrid tumors located in the subcutis of the trunk have not previously been reported to affect the pleura. We describe a 52-year-old man with dyspnea and thoracic pain due to a large mass in the right pleura, histologically composed of densely packed, S-100-positive spindle cells, intermixed with cells containing slender nuclei positive for epithelial membrane antigen, Glut-1, and claudin-1. To our knowledge, this is the first report of hybrid schwannoma/perineurioma in the pleura., (Copyright © 2014 The Japanese Respiratory Society. Published by Elsevier B.V. All rights reserved.)

We present 2 cases of blastic plasmacytoid dendritic cell neoplasm (BPDCN) showing unusual histological features. One patient, a 73-year-old male, presented with a nonpruritic macular erythema of the skin on the anterior and posterior chest wall, the biopsy of which was originally diagnosed as malignant melanoma. The neoplastic cells were negative for S100 and HMB45 and strongly positive for CD45, CD4, CD56, and CD123. The final diagnosis was a BPDCN associated with abundant melanin pigment and numerous melanophages. The second patient was a 73-year-old male with a 5-month history of small, slowly enlarging, bruise-like plaques on his limbs and chest. Histologic examination of the skin biopsy revealed an atypical cellular/myxoid infiltrate with numerous macrophages, which was originally diagnosed as consistent with lepromatous leprosy. The atypical cells were immersed in an alcian blue-positive myxoid matrix at pH 2.5. The Fite-Faraco stain was negative. Positive immunoreactivity was demonstrated for CD4, CD56, and CD123. Based on the histopathology and immunohistochemistry findings, a diagnosis of BPDCN with prominent myxoid matrix was rendered.

Synovial sarcoma (SS) arises primarily in the lower extremities with a predilection for sites in proximity to large joints, such as the knee. It rarely occurs in the head and neck region, and the tonsil is an unusual site for the tumor, with only eight previously published cases in this anatomical site. We present a case of a primary monophasic SS arising in the right tonsil in a 63-year-old male. His medical history was noncontributory. Immunohistochemistry showed that cytokeratin OSCAR, EMA, Bcl-2, vimentin, PGP 9.5, and TLE1 were diffusely positive. A molecular analysis using RT-PCR indicated that the patient was positive for the SYT/SSX1 fusion transcript. A diagnosis of monophasic synovial sarcoma of the tonsil was made.

Human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma has been identified as a distinct entity within squamous cell carcinoma of the head and neck. In contrast to carcinomas associated with alcohol and/or tobacco, this subtype occurs at younger age, with frequent absence of classic risk factors, correlation with oral sexual habits, strong predilection for the palatial tonsils and the base of the tongue (lingual tonsils), basaloid or lymphoepithelial differentiation, higher degree of radiosensitivity, and overall better survival. We report two cases of lymph node, metastatic, poorly differentiated squamous cell carcinoma that were positive by immunohistochemistry for p16 with detection of HPV-16 and HPV-45 by PCR.

Mixomas are the most common primary cardiac tumors with an estimate incidence of 0,5-1 per 10(6) individuals per year. These tumors have generated interest due to their unique location (left side of the atrial septum near the fossa ovalis), variable clinical presentation and undefined histogenesis. Most cardiac myxomas occur sporadically while approximately 10% of diagnosed cases develop as part of Carney complex. This neoplasm is of uncertain histogenesis, however, endothelial, neurogenic, fibroblastic, and cardiac and smooth muscle cells differentiation has been proposed, and rarely glandular differentiation has been observed. Recently, due to the expression of certain cardiomyocyte-specific factors, an origin of mesenchymal cardiomyocytes progenitor cells has been suggested. Histologically cardiac myxomas are mainly composed of stellated, fusiform and polygonal cells, immersed in an amorphous myxoid matrix. Immunohistochemically some endothelial markers, such as CD31, CD34, FVIIIAg, are present. Positive staining has also been reported for S-100 protein, calretinin, vimentin, desmin, smooth muscle myosin, CD56, α1 antitrypsin and α 1antichymotrypsin. Surgical resection is currently the only treatment of choice. We present in this article a histopathological and immunohistochemical review of cardiac myxomas., (Copyright © 2012 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.)

Non-Hodgkin lymphoma comprises a heterogeneous group of haematological malignancies, classified according to their clinic, anatomic-pathological features and, lately, to their molecular biomarkers. Despite the therapeutic advances, nearly half of the patients will die because of this disease. The new diagnostic tools have been the cornerstone to design recent therapy targets, which must be included in the current treatment guidelines of this sort of neoplasms by means of clinical trials and evidence-based medicine. In the face of poor diagnoses devices in most of the Mexican hospitals, we recommend the present diagnose stratification, and treatment guidelines for non-Hodgkin lymphoma, based on evidence. They include the latest and most innovative therapeutic approaches, as well as specific recommendations for hospitals with limited framework and therapy resources.

A 33 year-old woman presented with numerous 3- to 5-mm red-brown and yellow-brown dome-shaped nodules, primarily located on the scalp, dorsal aspects of the forearms, and lower extremities (Figure 1 and Figure 2). Her lesions started to appear 5 years prior to her consultation with increasing number and without spontaneous regression. Findings from a previous biopsy revealed epithelioid dermatofibroma. The remainder of the physical examination was unremarkable. There were no familial cases of this condition (both the mother and two older sisters were examined).

Involvement of the tongue by a synovial sarcoma (SS) is an extremely rare event; there have only been 13 cases previously reported. The authors present herein a case of monophasic SS arising in the tongue in a 32-year-old woman. The neoplasm expressed cytokeratins AE1-3, OSCAR, and EMA as well as Bcl-2 and TLE1. Molecular analysis indicated that the patient tested positive for the SYT/SS2 fusion transcript.