T-cell-rich B-cell non-Hodgkin's lymphoma mimicking Hodgkin's disease.

We report on a patient with recurrent T-cell-rich B-cell lymphoma (TCRBCL), initially misdiagnosed as a lymphocyte-rich Hodgkin's disease. This case exemplifies the diagnostic problems of TCRBCL and the need for immunophenotypic analysis to differentiate TCRBCL from Hodgkin's disease, nodular paragranuloma and peripheral T-cell lymphoma. A rather unusual aspect is the long disease-free interval between the excision of the node in and the late relapse in 1996. The significance of the abundant T-cell infiltration in this B-cell neoplasm will be discussed and the concepts concerning antitumor response will be reviewed. Based on epidemiological data and the clinical behaviour TCRBCL does not seem to represent a distinctive pathological entity.

Carcinoid of the pancreas: clinical characteristics and morphological features.

The classical carcinoid tumour (WHO) of the pancreas is extremely rare and its diagnosis may puzzle physicians and pathologists. Here, 29 previously published cases of pancreatic carcinoid tumours, including one new case, are reviewed. Literature research was done using MedLine from 1966 to 1995. Pancreatic carcinoids produce an atypical carcinoid syndrome. Skin flushing was reported in only 34%. The main symptom was pain, followed by diarrhoea and weight loss. Elevated urinary 5-HIAA levels were found in 85% (17/20). The immunocytochemical sensitivity for serotonin was 100% (11/11). The diagnosis of pancreatic carcinoid tumour is based on the typical endocrine histological features together with increased serotonin metabolism. Generally, the slow growth rate and late invasion of adjacent organs render local resection possible, but the high incidence of distant metastases (69%) prevents long-term survival in the majority of patients. The possible role of the Octreoscan, a new radionuclide imaging technique, is discussed with regard to this tumour entity.

Primary malignant mixed Müllerian tumor (metaplastic carcinoma) of the female peritoneum. A clinical, pathologic, and immunohistochemical study of three cases and a review of the literature.

BACKGROUND: Malignant mixed mesodermal tumors (malignant mixed Müllerian tumors [MMMT]) occur rarely in extragenital sites. METHODS: The authors analyzed the clinical, pathologic, and immunohistochemical features of three cases of primary MMMT of the female peritoneum. RESULTS: The neoplasms occurred in 60-, 64- and 84-year-old women and arose from pelvic peritoneum. Two patients died with disseminated disease 8 and 24 months postoperatively. The third died of cardiac failure 12 months postoperatively with questionable metastatic disease. Microscopically, two tumors were of the heterologous type, containing foci of rhabdomyosarcomatous (case 1) and chondrosarcomatous (case 3) differentiation. Immunohistochemically, coexpression of keratin and vimentin was observed focally in both carcinomatous and sarcomatous components in all three neoplasms, whereas coexpression of low molecular weight cytokeratin, vimentin and actin was observed focally in case 2. Rhabdomyosarcomatous areas were positive with desmin and actin, and chondrosarcomatous areas for S-100 protein. Both epithelial and mesenchymal components were positive for alpha-1 antichymotrypsin in all cases. CONCLUSIONS: On the basis of the present cases and a review of 15 reports from the literature, primary MMMT of the female peritoneum proved to be a rare but highly malignant neoplasm occurring in elderly postmenopausal women. Of 15 patients with available follow-up, 12 died with disease, mostly within 1 year, regardless of the initial tumor stage, histology (homologous versus heterologous MMMT) or treatments attempted. The tumor developed within pelvic peritoneum in half the cases. Histogenetically, peritoneal MMMT are thought to represent "metaplastic" carcinomas originating from the secondary Müllerian system.