The pigmented "black" neuroendocrine tumor of the pancreas: a question of origin.

BACKGROUND: Pigmented neoplasms are extremely rare in the pancreas, and, when black pigment is identified, it often suggests the diagnosis of metastatic melanoma. The authors describe two patients with pigmented "black" neuroendocrine tumors of the pancreas. One patient had an incidental (0.5 cm) finding, and the second patient had a well-demarcated, 4.5-cm mass identified by computerized tomography that was consistent with an islet cell tumor. METHODS: The two neoplasms were resected surgically and studied by light microscopy using hematoxylin and eosin (H&E), Fontana-Masson, and iron stains. The neoplasms were examined immunohistochemically, and ultrastructural analysis was performed. RESULTS: H&E stains revealed nests of well-differentiated cells with small, round, centrally placed nuclei. The cytoplasm of the neoplastic cells was pink and granular and contained abundant brown-black pigment. Angiolymphatic and perineural invasion were identified in the larger neoplasm. Both neoplasms demonstrated a positive reaction with a Fontana-Masson stain, which was susceptible to bleaching, and a negative reaction to an iron stain. Immunohistochemical stains showed that neoplastic cells expressed chromogranin and synaptophysin but did not express HMB-45, S-100 protein, glucagon, or insulin. Ultrastructural examination revealed regular neurosecretory granules (100-150 nm) and large, irregularly shaped, electron-dense granules with small lipid inclusions consistent with lipofuscin. CONCLUSIONS: These pigmented pancreatic neoplasms are similar histologically and radiographically to the "black adenoma" of the adrenal gland. It is important to recognize these tumors, because they may mimic metastatic melanoma.

Langerhans cell histiocytosis of the thyroid: a report of two cases and review of the literature.

Langerhans cell histiocytosis (LCH) is a monoclonal disease of histiocytes that can involve many or very few organ systems. It is a relatively benign disorder with a 3% mortality in adults. LCH rarely involves the thyroid gland. We report two cases, both presenting in males with a goiter. Both patients were treated with subtotal thyroidectomy. The first patient also received radiotherapy to his thyroid bed and scalp. We summarize the prior reported cases of LCH involving the thyroid and review the current treatment modalities used for LCH.

Clinical significance of denuded urothelium in bladder biopsy.

PURPOSE: Although to our knowledge the significance of denuded urothelium in bladder biopsies has not been studied previously, it is thought to be a problem because benign urothelial cells are cohesive and not expected to shed into the urine. We correlated the pertinent clinical features of patients with denuded bladder biopsies and/or specific pathological features of denuded bladder biopsy specimens with patient outcome in regard to bladder lesions to help predict the subsequent likelihood of diagnosing bladder carcinoma in a patient with a nondiagnostic denuded biopsy. MATERIALS AND METHODS: We studied 51 denuded bladder biopsies from 44 patients in which the average extent of epithelial denudation was 90%. RESULTS: Of the 27 male (69%) and 17 female (31%) patients 22 to 86 years old (mean age 62) 34% had no history of bladder neoplasms. In remainder there were flat carcinoma in situ with or without other tumors (26%), high (20%) and low (14%) grade papillary tumors without carcinoma in situ and miscellaneous conditions (6%). Overall 31% of patients were diagnosed with carcinoma in situ within 24 months (median 5.5) after the denuded specimen was obtained. Parameters that did not correlate with the subsequent diagnosis of carcinoma in situ included cystoscopic impression, history of intravesical chemotherapy, sex, age, tissue inflammation, percent of tissue fragments with any denudation, number of denuded tissue fragments and percent of overall denuded epithelium. A history of carcinoma in situ before denuded biopsy predicted a diagnosis of carcinoma in situ within 24 months after denuded biopsy in 54% of patients in contrast to 19% of those without a history of carcinoma in situ (p = 0.03). Factoring in a history of other bladder tumor types in various combinations did not predict carcinoma in situ after denuded biopsy. The other predictive factor was cold cup biopsy. Carcinoma in situ developed within 24 months in 45% of patients in whom the denuded specimen was obtained by cold cup biopsy in contrast to none who underwent hot wire loop biopsy (p = 0.007). Cold cup biopsy and a history of carcinoma in situ were independently predictive. Carcinoma in situ developed within 24 months in 75% of patients with a history of that condition and a subsequent cold cup biopsy showing denuded epithelium. However, only 29% of those who underwent cold cup biopsy and had no history of carcinoma in situ were diagnosed with carcinoma in situ. CONCLUSIONS: In bladder biopsies obtained by a hot wire loop denudation most likely results from thermal injury when there is a low risk of subsequent carcinoma in situ. When the denuded biopsy sample was obtained by cold cup biopsy, particularly when associated with a history of carcinoma in situ, most cases represent neoplastic cell denudation and a high risk for subsequent carcinoma in situ.

Coexistent choriocarcinoma and malignant mixed mesodermal tumor of the uterus.

OBJECTIVE: The purpose of this article is to report a case of coexisting uterine choriocarcinoma and uterine malignant mixed mesodermal tumor (MMMT). The relevant literature is reviewed and possible pathogenesis discussed. METHODS: The clinical course and histopathology of the case were reviewed and a Medline literature search for other cases was performed. RESULTS: The patient's uterine tumor contained syncytiotrophoblastic and cytotrophoblastic cells that stained positively for the beta subunit of human chorionic gonadotrophin consistent with uterine choriocarcinoma. Pathology also revealed a second distinct neoplasm composed of adenocarcinoma admixed with sarcoma, compatible with a uterine MMMT. The patient experienced metastatic choriocarcinoma to her lungs, lymph nodes, and brain. She suffered a complicated clinical course and died 7 months after her initial diagnosis. The literature search revealed that various gynecologic and nongynecologic carcinomas with trophoblastic differentiation have been described, but an association with uterine MMMT has not been previously reported. CONCLUSIONS: Trophoblastic differentiation and choriocarcinoma associated with gynecologic and nongynecologic tumors is rare. We document the presence of uterine MMMT coexisting with uterine choriocarcinoma that followed an aggressive clinical course and review the possible pathogenesis of this lesion.

Pseudohyperplastic prostatic adenocarcinoma on needle biopsy and simple prostatectomy.

Prostatic adenocarcinoma resembling benign hyperplastic glands architecturally is a recently recognized entity. In the only prior study on this entity, 100 needle biopsies were studied and only two contained carcinoma with pseudohyperplastic features, which occupied a small percentage of the cancer. The current study investigates histologic attributes of pseudohyperplastic prostatic adenocarcinoma on needle biopsy and simple prostatectomy in which the pseudohyperplastic regions represent the majority of the cancer. The authors reviewed outside cases received in consultation by one of the authors (J.I.E.) and the surgical pathology files of Johns Hopkins Hospital from January 1991 to August 1998 and identified 20 cases of needle biopsy and simple prostatectomy in which > or =60% of the cancer had benign architectural features. The majority (19 of 20) were consult cases. Of the 20 cases studied, 16 were needle biopsies, two were transurethral resections of the prostate, and two were enucleations. Cancer involved one core in 75% of the needle biopsies. In 13 of the 20 cases (65%), > or =90% of the cancer had pseudohyperplastic features. Benign features included papillary infoldings in all cases, large atypical glands in 95% of cases, branching in 45% of cases, and corpora amylacea in 20% of cases. The extent of pseudohyperplastic cancer ranged from 1.0 to 10.0 mm (average, 3.7 mm). Within the pseudohyperplastic foci, features helpful in establishing a malignant diagnosis were nuclear enlargement in 95% of cases, pink amorphous secretions in 70% of cases, occasional to frequent nucleoli in 45% of cases, and crystalloids in 45% of cases. Other features associated with malignancy (mitoses, blue-tinged mucin, adjacent high-grade prostatic intraepithelial neoplasia, and perineural invasion) were seen infrequently. Immunohistochemical stains for high-molecular weight keratin showed an absence of basal cells in the pseudohyperplastic areas in all 20 cases, confirming the diagnosis of cancer. It is critical to recognize pseudohyperplastic prostatic adenocarcinoma and the features needed to establish a malignant diagnosis so these carcinomas are not misdiagnosed as benign.