Merkel cell carcinoma: a clinicopathological study of 11 cases.

OBJECTIVE: To report our 12-year experience with Merkel cell carcinomas (MCCs) from a clinical and pathological point of view. SUBJECTS AND SETTING: Eleven MCCs were diagnosed at our institution between 1991 and 2002. METHODS: A retrospective clinical, histopathological and immunohistochemical study was performed. Age, gender, location, size, stage, treatment and follow-up data were collected. Histopathological pattern and immunohistochemical study with CAM 5.2, cytokeratin 20 (CK20), CK7, Ber EP4, neurofilaments, synaptophysin, chromogranin, S100 protein, p53 protein, CD117, leucocyte common antigen (LCA) and Ki-67 were accomplished. RESULTS: Six females and five males with a mean age of 82 years were identified. Tumours were located on the face (n = 6), extremities (n = 3) and trunk (n = 1). At diagnosis, one patient was in stage Ia, six in stage Ib, three in stage II and one in stage III. All but one patient experienced wide surgical excision of the tumour. Additional treatment consisted of lymph node dissection in two patients, radiotherapy in four patients and systemic chemotherapy in one patient. Local recurrence developed in five patients. Three patients died because of MCC after 14 months of follow-up. Intermediate-size round cell proliferation was found in all cases. Additional small-size cell pattern and trabecular pattern were observed in seven and six cases, respectively. Eccrine and squamous cell differentiation were found in three cases. A dot-like paranuclear pattern was observed in all cases with CAM 5.2 and neurofilaments, and in 89% of cases with CK20. Seventy-five per cent of cases reacted with Ber EP4, chromogranin and synaptophysin, 70% with p53, 22% with S100 protein, 55% with CD117 and none with LCA. Ki-67 was found in 75% of tumoral cells on average. Fifty per cent of MCCs reacted with CK7 and showed eccrine differentiation areas. CONCLUSIONS: MCC is an aggressive neuroendocrine tumour of the elderly. Wide surgical excision is the recommended treatment. Lymph node dissection, adjuvant radiotherapy and chemotherapy decrease regional recurrences but have not been demonstrated to increase survival. Immunohistochemically, MCC is an epithelial tumour with neuroendocrine features.

[Testicular metastasis of renal adenocarcinoma. Report of a case]. / Metástasis testicular de adenocarcinoma renal. Presentación de un caso.

Metastatic tumors of the testis are extremely rare, if we exclude leukemias and lymphomas. The present article reports a case of renal adenocarcinoma metastatic to the testis that presented with paraneoplastic syndrome, hematuria and a palpable testicular mass. The literature on metastatic tumors of the testis is briefly reviewed.

[Muscle changes in chronic obstructive arteriopathy: a morphological, histochemical and morphometric study]. / Alteraciones musculares en la arteriopatía obstructiva crónica: estudio morfológico histoquímico y morfométrico.

Muscular alteration due to chronic obstructive arteriopathy in lower extremities was studied in 50 patients. An arteriosclerotic pure clinical picture was found in a 50% of them, while the other were associated to diabetes. Histopathological features present in both groups were quite similar and no substantial differences between diabetic and non diabetic patients were found. In patients with an acute clinical course, myopathic changes predominate in tibialis anterior muscle. However, neuropathic alterations were more frequently found in patients with a chronic clinical course. Although histological changes characteristic of chronic obstructive arteriopathy do not exist, this disease can be defined by a characteristic association of muscle lesions that will constitute the "chronic ischaemic myopathy" histological picture. Because of this, muscle biopsy examination in such patients will deliver important information to orient therapeutic attitudes and prognostic predictions.

Muscle fiber types in tetrapods. A comparative histochemical and morphometric study.

A comparative histochemical and morphometric study in two groups of homologous muscles from different tetrapods (rat, pigeon, lizard and frog) was performed. On the basis of their fiber diameters and oxidative enzyme activities, an initial correlation between fiber types of all animals is observed, although in the lizard and frog muscles, another fiber type does exists that could not be demonstrated in higher vertebrates. When more than one histochemical techniques are used for the identification of each tetrapod fiber types, the lack of correlation between them becomes obvious. Thus, different animals groups, each showing a characteristic muscle metabolic pattern, could be distinguished.

Benign schwannomas: a histopathological and morphometric study.

A conventional histopathological and quantitative morphometric study of 28 capsulated peripheral and spinal nerve benign schwannomas demonstrated linear and parabolic correlation between Antoni B tissue, vascularity and tumour size. The results support the endoneural connective tissue origin of Antoni B, and suggest a model of tumor growth that is partially limited by the growth potential of the Antoni B and/or the vascular component.

Focal fibrous disease of breast. A common entity in young women.

The study concerns a problem of practical importance in the daily routine work. 218 cases of focal fibrous disease of the breast were classified into three types with conventional methods of pathohistology and statistics. The peak incidence between 20 and 25 years is considerably lower than the incidence figures reported by other authors. The authors postulate the progressive evolutive nature of the lesion.