Transsphenoidal surgery can achieve a good long-term outcome in patients with thyrotropin-secreting pituitary adenomas if surgery is performed before these become larger, invasive tumors. In the authors' experience, thyrotropin-secreting adenomas are fibrous and firm, which makes it difficult to achieve surgical remission. In addition, even satisfactory resection of the tumor sometimes results in recurrence of SITS or hyperthyroid symptoms due to coexistent primary hyperthyroidism. It is emphasized that a careful follow-up review is necessary after surgery, especially in patients with a long preoperative history of hyperthyroidism.

This is a case report of a 20-year-old woman who had primary angiosarcoma of the left breast, with metastases to the spleen and ovary. Eight months after detecting a mass in her breast, she underwent mastectomy with biopsy of the ipsilateral axillary lymph nodes, splenectomy and bilateral oophorectomy. Five months after the operation, the patient succumbed to lung metastases. Angiosarcoma of the breast is a rare condition with a poor prognosis, and there are no established chemotherapeutic regimens as yet. Immunohistochemical staining for endoglin, known to be expressed mainly on the surface of endothelial cells, was positive. This suggests the possibility of treating angiosarcoma with anti-endoglin monoclonal antibodies.

Immunoperoxidase analysis was performed to evaluate the phenotypic expression of eight renal differentiation antigens in five nephroblastomas, one clear cell sarcoma of the kidney (CCSK), one rhabdoid tumor of the kidney (RTK), and four related tumors. A total of 19 fetal and pediatric kidneys, including two 6th-week mesonephric tissues, were comparatively studied. All the specimens were fixed in formalin and embedded in paraffin. Neural cell adhesion molecule (NCAM), a marker of the nephrogenic zone of the developing kidney, was consistently expressed in the epithelial and blastematous components of nephroblastomas of the common type. The epithelial components also commonly expressed NK1 and Leu 7 (CD57), and the findings may reflect that both were positive in immature proximal tubules directly differentiating from the NCAM-positive immature fetal tubuloglomerular buds. In two cases, the epithelial component was immunoreactive for CD10 and WT1 gene product (WT1-GP). Leu M1, epithelial membrane antigen and CA15-3 were only focally expressed in nephroblastomas. Rhabdomyoblasts in the stroma were positive for WT1-GP. CCSK was featured by the expression of NCAM and CD10. In RTK, focal epithelial differentiation was discerned, with focal positivity of WT1-GP and negativity of NCAM. In congenital mesoblastic nephroma, the stromal spindle cells were strongly immunoreactive for WT1-GP, while WT1-GP was not expressed in solitary multilocular cyst of the kidney. Pancortical nephroblastomatosis was featured by the diffuse subcapsular reappearance of immature metanephric tissue. Nephroblastomas and related conditions thus offer an adequate model for studying human nephrogenesis.

Poorly differentiated small cell neuroendocrine (NE) carcinoma of the colon and rectum is a rare primary epithelial malignancy at this location. A case of a highly aggressive NE tumor of small cell type, combined with non-invasive well-differentiated papillary adenocarcinoma in villous adenoma is reported. The patient died rapidly with massive and progressive liver metastasis. The tumor cells were argyrophilic and diffusely immunoreactive for neuronspecific enolase and synaptophysin. Ultrastructural analysis disclosed NE-type cored granules in most of the small tumor cells. NE tumors of the colon and rectum are briefly reviewed.

method has been employed widely to demonstrate apoptotic cells in routinely prepared paraffin sections. Because the apoptotic cells were reactive with the antibody to singlestranded DNA, we attempted to enhance the TUNEL positivity by pretreatment with single-stranded DNA digestion enzymes, S1 nuclease, and mung bean nuclease. When mung bean nuclease (5 Ul50 pllsection) was incubated at 37°C for 30 min, the TUNEL reaction was most effectively enhanced. Pretreatment with S1 nuclease (0.25 Ul50 pl/sec-