Primary small cell neuroendocrine carcinoma of the urinary bladder: a clinicopathologic, immunohistochemical, and ultrastructural evaluation.

Small cell neuroendocrine carcinoma (SCNEC) of the urinary bladder is a rare but aggressive neoplasm that usually exhibits neuroendocrine differentiation. Here, the authors report a case of SCNEC in an 80-year-old man. The patient had gross hematuria and nodular mass involving the wall of the urinary bladder. Total cystectomy was done. The tumor consisted of small, uniform, round, and spindled-shaped cells with chromatin dark nuclei and numerous mitotic figures. The cells were reactive for chromogranin, neuron-specific enolase (diffuse), and keratin (focal). Ultrastructural studies revealed neurosecretory granules and intermediate filaments. The diagnosis of SCNEC with focal high-grade urothelial component was established. No metastasis was found at the time of diagnosis and the patient refused further chemotherapy or radiotherapy. The histogenesis, differential diagnosis, and prognosis of SCNEC of the urinary bladder were discussed.

Phenotypic characterization of the infiltrating immune cells in normal prostate, benign nodular prostatic hyperplasia and prostatic adenocarcinoma.

BACKGROUND: Immune cell infiltrate is a constant feature in normal prostate, benign nodular prostatic hyperplasia and prostatic adenocarcinoma. This study elaborates on the cells of the immune system present in normal prostate, benign nodular prostatic hyperplasia and prostatic adenocarcinoma. HYPOTHESIS: Here, we hypothesized that "the development of benign nodular prostatic hyperplasia and prostatic adenocarcinoma is associated with numeric alterations of the immune cell infiltrate". MATERIALS AND METHODS: A total of 50 transurethral prostatic resection specimens, each entailing normal prostate, benign nodular prostatic hyperplasia and high grade prostatic adenocarcinoma were evaluated for the density and phenotype of the immune cells using immunohistological methods and mouse monoclonal antibodies decorating T cells (CD3), histiocytes (CD68) and B lymphocytes (CD20). RESULTS: Immune cell infiltrate was composed of T cells, histiocytes and B-lymphocytes. CD(+)3 T lymphocytes and CD68(+) cells were the predominant cell populations. We observed variations in the density of the immune cells among the normal prostate, benign nodular prostatic hyperplasia and high grade prostatic adenocarcinoma. Compared with normal prostate, benign nodular prostatic hyperplasia had a statistically significant high density of immune cells (3.4+/-0.4versus 13.5+/-1.0, P<0.00). In contrast, a significant decrease in the counts of these cells was observed in high-grade prostatic adenocarcinoma compared to benign nodular prostatic hyperplasia (13.5+/-1.0 versus 5.2+/-0.3, P<0.01). CONCLUSIONS: The increased density of immune cells (predominantly CD(+)3 T cells) in benign nodular prostatic hyperplasia suggests that the initial response to cellular damage is mediated by cell-mediated immunity. The decreased density of immune cells in high-grade prostatic adenocarcinoma may reflect immunosuppression. The underlying mechanisms of these numeric variations are open for further investigations.

Histological and ultrastructural features of gastrointestinal basidiobolomycosis.

Basidiobolus ranarum is a fungus found in the dung of amphibians, reptiles, and insectivorous bats. Its structural elements include both hyphae and zygospores. Patients with B. ranarum infection may present with subcutaneous, gastrointestinal, or systemic lesions. Here we report a case of gastrointesinal badidiomycosis in a 13-year-old male child who presented with acute abdomen. Exploration revealed a mass in the ascending colon. On histology, transmural granulomatous inflammation composed of abundant eosinophils, lymphocytes, histiocytes and giant cells was seen. Histochemical stains revealed broad, non-septate, hyphae-like structures surrounded by an eosinophilic sheath. On an ultrastructural level, fungal hyphae, spores, and macrophage-laden crystalloids were observed. The diagnosis of gastrointestinal basidiobolomycosis was established and the patient received antifungal treatment. This paper reviews the relevant literature regarding basidiomycosis, and discusses its diverse clinicopathological features, as well as distinguishing it from other diseases.