[Xanthogranulomatous cystitis: report of a case]. / Cistitis xantogranulomatosa: presentación de un caso.

OBJECTIVE: To report a case of xanthogranulomatous cystitis, a rare disease especially in the western countries (12 of the 16 cases reported were Japanese and Korean). METHODS: A case of xanthogranulomatous cystitis in a 34-year-old female is presented. Patient evaluation included histological, histochemical and immunohistochemical studies. RESULTS/CONCLUSIONS: The lesion was localized to the bladder dome, anatomically related with the urachus. It consisted of collections of histiocytes with lymphoplasmocytic infiltrate. The adhesions observed in the omentum in this case indicate a possible relationship with a previous inflammatory process. Surgery is advocated in most of the cases with good results.

Embolization of mesothelial cells in lymphatics: the route to mesothelial inclusions in lymph nodes?

AIMS: To provide evidence that lymphatic embolization is the mechanism for mesothelial inclusions in lymph nodes. METHODS AND RESULTS: A 60-year-old man with alcoholic cirrhosis and ascites had an umbilical hernia resected. The herniorrhaphy specimen contained numerous dermal and submesothelial lymphatic vessels filled by cells similar to the cells that lined the hernia sac. Most of the cells in lymphatics were submesothelial reactive cells, whose cytoplasm stained with antibodies against cytokeratins (AE1-AE3; 8, 18), smooth muscle actin, vimentin, desmin and tissue polypeptide antigen (TPA). Some cells seemed to be superficial mesothelial cells, being positive with high molecular weight anticytokeratin antibody 34 beta E12. On ultrastructural study submesothelial cells with intermediate cytoplasmic filaments, rough endoplasmic reticulum and primitive cell junctions, and scanty superficial mesothelial cells with microvilli, tonofilaments and desmosomes were found in the lymphatics. CONCLUSIONS: Lymphatic dissemination of mesothelial and submesothelial cells is an uncommon and not well known phenomenon. Lymphatic dissemination is probably the route by which the mesothelial cells reach the lymphatic nodes. These cells may be mistaken for malignant cells.

[Squamous carcinoma of the esophagus with extensive pagetoid dissemination]. / Carcinoma escamoso de esófago con extensa diseminación pagetoide.

A case of squamous carcinoma of the esophagus with pagetoid spreading in a 59-year-old male in presented. Signs of glandular differentiation (PAS-diastase, Alcian blue) and CEA were negative in the Paget-like cells. Pagetoid spreading of squamous carcinoma and true Paget's disease are very similar histologically and very rare in the esophagus (only 6 cases reported) and they must be differentiated from each other. Paget's disease demonstrates glandular differentiation and the cells are CEA positive. The absence of glandular differentiation in the Paget-like cells of pagetoid spreading versus Paget's disease may be a good criteria to differentiate these diseases.

[An undifferentiated neuroendocrine carcinoma of the rectum with cervical metastases]. / Carcinoma indiferenciado neuroendocrino de recto con metástasis cervicales.

Sigma undifferentiated carcinoma of the rectum is a neuroendocrine tumor embracing less than 1% of all primary malignant epithelial tumors in this location. Recent studies have demonstrated that these tumors are biologically aggressive neoplasias with early metastatic extension. We present one case of loco-regional invasion at the time of the intervention and with distal metastasis within a period of time shorter than one year. We perform a clinical, histological and immunohistochemical study and we comment on the histogenesis of these tumors, their prognosis and treatment, stressing the need of an early diagnosis, an aggressive treatment and an adequate follow-up.

[Congenital mesoblastic nephroma in an adult: immunohistochemical study]. / Nefroma mesoblástico congénito en el adulto: estudio inmunohistoquímico.

A case of congenital mesoblastic nephroma in a 60-year-old female patient is described. The clinical onset was gross hematuria of 48 hours evolution and pain in the right renal fossa which irradiated to the iliac fossa of the same side. A routine pathological analysis was carried out on the surgical specimen including an extensive immunohistochemical analysis which was highly positive for keratin in the epithelial lining of the tubular and cystic structures and for desmine and vimentin in the fusocellular stroma of the tumor. The different histogenetic hypotheses are discussed. The importance of a precise anatomopathological diagnosis in order to institute adequate treatment is underscored.

Thymic carcinosarcoma associated with a spindle cell thymoma: an immunohistochemical study.

A case of thymic carcinosarcoma associated with a spindle cell thymoma in a 71-year-old woman is reported. Histological and immunohistochemical studies of the carcinosarcoma showed two quite different components: the sarcomatous component included cells with myoid differentiation which stained for desmin and muscle specific actin, and some isolated cells which stained positively for low molecular weight cytokeratin, while the carcinomatous component, which formed less than 10% of the tumour, showed an epithelial phenotype, being positive for low and high molecular weight cytokeratin and epithelial membrane antigen. The thymoma cells showed epithelial markers, and a few cells were also positive for desmin and muscle specific actin. The rarity of this tumour and its possible histogenesis are discussed.

[Undifferentiated small-cell carcinoma of the urinary bladder]. / Carcinoma indiferenciado de células pequeñas de vejiga urinaria.

We report a case of undifferentiated small cell carcinoma of the urinary bladder in a 64-year-old male patient. Microscopically the tumor was similar to the intermediate type of small cell carcinoma of the lung, with some foci of transitional papillary carcinoma, adenocarcinoma and carcinoma in situ. Small cell carcinoma is seldom encountered in the urinary bladder. It is more aggressive and must be distinguished from poorly differentiated transitional cell carcinoma.