Search

von Hippel-Lindau disease (VHL) is an autosomal dominant familial syndrome that predisposes to the formation of tumors in multiple organ systems, including adrenal and extra-adrenal pheochromocytomas. However, fewer than 30% of VHL families develop pheochromocytomas. In recent years, this clinical heterogeneity has been correlated with missense mutations. The VHL patient requires vigilant, lifelong biochemical and radiographic screening for pheochromocytoma. Half of VHL pheochromocytomas present bilaterally, and there is a high incidence of recurrence after surgery. Because of the morbidity of bilateral total adrenalectomy with subsequent steroid replacement therapy, the recent therapeutic trend has been toward observation and minimally invasive adrenal-sparing procedures.

Purpose: We present preliminary clinical, histochemical and molecular findings for 5 patients with micropapillary transitional cell carcinoma of the bladder, a rare histological variant not widely recognized in the urological literature., Materials and Methods: The 5 patients were prospectively identified. In 3 cases immunohistochemical staining for expression of CD31, p53, E-cadherin, and alpha, beta and gamma-catenin was performed on paraffin embedded tissue. Sequencing was used to identify point mutations in exons 5 to 9 of p53, and exons 1 and 2 of H-ras., Results: Of the patients 2 died within 1 year of presentation to our institution with rapid local extension along the bladder serosal surface and ureteral sheaths. Another patient had progression to invasive disease within 22 months. In the 3 cases with immunohistochemical staining p53 was negative, despite positive staining of nonmicropapillary transitional cell carcinoma within the same specimen. Stains for the angiotrophic marker CD31 were negative. In all 3 cases normal membrane associated alpha, beta and gamma-catenin expression was present. Examination of p53 sequences revealed a single point mutation in exon 8 of 1 case. In 2 cases different mutations in exon 1 of H-ras were noted., Conclusions: Micropapillary transitional cell carcinoma is a rare and highly aggressive variant. Paradoxically, our study demonstrated no significant p53 abnormalities. The lacunar histological pattern did not appear to represent invasion of vascular spaces. Rather, these tumors seemed to have the ability to disrupt and replace the normal stromal matrix to achieve rapid nonendothelial extension. Thus, micropapillary histology may predict a lesser likelihood of surgical cure.