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Leydig cell nodular hyperplasia (LCNH) is a lesion that is less characterized than the familiar Leydig cell tumors. The paracrine effects of these lesions on adjacent gonadal stroma have not been widely documented. We present two cases of precocious puberty in pre-pubertal boys found to have a single LCNH with adjacent focal maturation of the seminiferous tubules. Blood tests showed elevated serum testosterone and dehydroepiandrosterone (DHEAS). Ultrasound revealed unilateral testicular enlargement with irregular echogenicity. Radical orchiectomy was performed. Histologically Leydig cell nodular proliferation without destruction of surrounding tubules was seen. Mature seminiferous tubules undergoing spermatogenesis were noted adjacent to the lesion, while away from the lesion seminiferous tubules were as expected in pre-pubescent boys. These cases emphasize the potential presence of both paracrine and endocrine effects in Leydig cell nodular hyperplasia. However, instances of the endocrine effects of hyperplastic Leydig cell lesions are more widely reported than the paracrine effects.

Noniatrogenic neonatal gastric perforation is a rare and life-threatening condition whose etiology is often unclear. Interstitial cells of Cajal act as gastrointestinal pacemaker cells and express the proto-oncogene c-Kit. Six new cases were identified at our institution which presented with no mechanical, pharmacologic, or otherwise medical-related intervention prior to rupture. The number of interstitial cells of Cajal in nonnecrotic muscularis propria from five random high-power fields per specimen was compared using immunohistochemical stains for c-Kit. The authors show that a lack of interstitial cells of Cajal in the stomach musculature may be implicated in the development of noniatrogenic gastric perforation (p = 0.008). Further large-scale studies, including molecular and genetic analysis, may help to better understand this phenomenon.

Epstein-Barr virus (EBV) may present few or no symptoms in immunocompetent individuals; however, in immunocompromised patients as in the case of AIDS and post-transplant patients, the virus occasionally stimulates neoplastic transformations. Epstein-Barr virus may play a role in the development of smooth muscle tumors (SMT). In the case of Epstein-Barr associated smooth muscle tumors (EBV+SMT), the virus is thought to be the leading factor to the tumorigenic pathway. We report two pediatric patients (6 and 13 years old) who underwent liver transplantation and developed EBV+SMT in the colon and orbit. These two cases represent rare locations for this kind of lesion.

Octamer4/3 is a POU transcription factor that regulates pluripotentiality in embryonic stem and germ cells and primordial germ cells. When expressed in post-embryonic life, Octamer4/3 may lead to malignant germ cell tumors (GCT). Thirty samples were selected for this study (26 GCT samples and 4 cryptorchid testes samples) and 16 non-GCT were used as controls. Samples were stained with an anti-Octamer4/3 antibody. All cases of GCT were positive for Octamer4/3, and the non-GCT were negative. This article focuses on pediatric populations where we found that Octamer4/3 immunostaining is a useful diagnostic tool in undifferentiated pediatric tumors.

Hepatic pulmonary fusion (HPF) is characterized by a fibrous connection between the liver and lung tissue. We present two cases of hepatic pulmonary fusion diagnosed with right diaphragmatic hernia and a third case with Pentalogy of Cantrell exhibiting complete agenesis of the diaphragm and finger-like projections of liver adhered to the right lung. It has been proposed that this anomaly is secondary to developmental failure of the mesoderm between days 14-18 after conception and is attributed to diaphragmatic maldevelopment. Understanding the molecular-genetic basis of diaphragmatic hernias may shed light on this unusual presentation and explain why other cases show no fusion.

Parasitic infections of the central nervous system (CNS) occur mostly in underdeveloped regions of the world. Neurocysticercosis (NC) occurs when the larval form of the T. solium tapeworm invades the CNS. Spinal cysticercosis is an extremely rare type of NC and occurs when the cyst occupies the subarachnoid space of the spinal column. Previous cases have been successfully treated through both surgical and medical means. The current case describes the symptoms, diagnosis, and treatment of a patient with this extremely uncommon manifestation of neurocysticercosis.

Rosai-Dorfman disease (RDD), or sinus histiocytosis with massive lymphadenopathy (SHML), is a rare idiopathic histiocytic disorder. The usual presentation of RDD is painless bilateral cervical lymphadenopathy. Extranodal RDD with lymphadenopathy occurs in almost 50% of patients but extranodal RDD, without lymphadenopathy, is very rare. Isolated RDD in the bone occurs in only 2% of patients but it is histologically similar to its nodal counterpart. There are only 14 previously reported cases of RDD in the bone without lymph node involvement in children. Here we describe two new patients--one with rib and lung involvement and the other with multi-osseous involvement.

Congenital infantile fibrosarcoma (CIFS) is a rare mesenchymal tumor that primarily presents in the soft tissue of the distal extremities and occasionally in unusual locations such as the lung and retroperitoneum. Herein, we report seven cases of unusual presentations of CIFS. These cases include three in the lungs, one in the retroperitoneum with cord compression, one in the posterior trunk, one in the heart, and one infratemporal involving the sphenoid bone. All tumors demonstrated CIFS's characteristic t(12;15)(p13;q25) and associated ETV6-NTRK3 gene fusion. One of the three lung cases was previously reported as primary bronchopulmonary fibrosarcoma (PBPF), but molecular analysis of the paraffin embedded tissue revealed the ETV6-NTRK3 gene fusion consistent with CIFS. We show that CIFS may occur in unusual sites including visceral locations, and we propose that neoplasms displaying the ETV6-NTRK3 gene fusion represent the visceral components of CIFS.

Three cases of congenital immature intracranial teratomas were examined by autopsy. The fetuses were diagnosed prenatally as macrocephalic and hydrocephalic due to skull-occupying lesions. These fetuses were born alive at 32, 31, and 36 weeks gestation, respectively, via Cesarean section. Intracranial teratoma in the first case was diagnosed by MRI and in the second and third cases by ultrasound. All tumors were deemed to be unresectable. Congenital CNS teratoma should be considered in the differential diagnosis of fetuses diagnosed with macrocephaly or hydrocephaly.

Previous studies have suggested that immune mechanisms contribute to lung injury in cystic fibrosis (CF); however, there have been no comprehensive studies of immunofluorescent staining patterns in CF lung tissue. We performed immunofluorescence (IF) studies for immunoglobulins, C3, and fibrinogen on autopsy frozen lung tissue from 21 CF patients. Results were compared with lung findings in patients without CF. In CF-derived lung tissue fibrinogen was ubiquitous along the alveolar wall, alveolar space, and interstitium. Free immunoglobulin G (IgG) and IgA coated the alveolar surface segmentally in 14 and 6 cases, respectively. Unequivocal interstitial deposits were infrequent and IgM was present in blood vessels in one patient only. Intra-alveolar and interstitial inflammatory cells demonstrated cytoplasmic IgG, IgA, and IgM, respectively, in 18, 14, and 6 patients. C3 was seen only segmentally along the alveolar wall in two patients and in blood vessels in one. Antinuclear antibody (ANA) staining of interstitial cells for C3 and immunoglobulins was seen in five patients, four of whom had interstitial pneumonitis. Insignificant amounts of alveolar or interstitial fibrinogen and immunoglobulins in inflammatory cells were seen in controls in the absence of lung inflammation. The IF patterns were similar in the inflammatory lesions of CF and control specimens. The IF patterns observed in CF lung tissue are consistent with nonspecific vascular leakage and chronic inflammation with little evidence of immune complex deposition in the interstitium or blood vessels. This study confirms previous reports of ANA activity in CF patients, although the significance of this finding is unknown.

An irnmunogold-silver stainingmethod wasused to identify Treponemapallidum spirochetes in formalin fixed tissue. In an indirect immunohistochemical procedure, the colloidal gold particles bound to the secondary antibody were visualized by a silver developing solution to create a brown-black reaction product. This brown-black staining is similar to the stain generated with a Warthin-Starry technique. This method was superior to such techniques as the avidin-biotin complex immunoperoxidase method and indirect immunofluorescence method with ammonium hydroxide treatment and could also beused to stain other spirochetes and antigens that are difficult to visualize with other immunohistochemical techniques. (The J Histotechnol 14:243, 1991)

From 1980-1986 intestinal mucosal lymphangiectasia was diagnosed histologically in eight patients (6 weeks to 16 years; four males/four females; seven white). The presenting features were diarrhea (six/eight), vomiting (four/eight), and growth deficit (seven/eight). Additional conditions in these patients included asthma, urinary tract infection, esophageal atresia, hydrops fetalis, inflammatory bowel disease, malabsorption syndrome, and thymic hypoplasia. Hypoalbuminemia and edema (four/eight) were more prominent in those patients under 5 years of age. Two had systemic lymphangiectasia and lymphopenia. The patients responded variably to hyperalimentation and dietary supplements, depending on the extent of their lymphangiectasia and the age at onset of symptoms. Dilated lymphatics were seen in the small intestinal mucosa under the surface epithelium. Lesions were often focal, requiring several biopsies or serial sections for detection. Other common findings were mild to moderate lymphoplasmacytic inflammation and mild to moderate villous injury with blunting and edema. Mild inflammation without lymphangiectasia was also present in esophageal, gastric, or colonic biopsies. Diagnosis should be made on the basis of endoscopic findings or in small-intestinal inflammatory conditions even in the absence of a classic clinical picture. Histologic confirmation may require more than one serially sectioned biopsy. This study confirms the diversity of disorders that may be associated with intestinal lymphangiectasia and shows that the disease in infants is more severe and generalized.