Neuroendocrine metastatic tumors of the liver resembling hepatocellular carcinoma

Certain neuroendocrine tumors (NET) metastasized to the liver can resemble hepatocellular carcinoma (HCC) in cytological needle biopsy. Experience concerning the histologic characteristics of metastatic NET resembling HCC in core needle hepatic biopsies has been scarce. The aim of this study is to describe the histological criteria in seven metastatic NET that resembled HCC in core needle hepatic biopsy. From a total of 285 needle biopsies with primary or metastasized hepatic neoplasms, seven cases were selected originally diagnosed as HCC or HCC vs. NET metastasized to the liver. Fourteen needle biopsies of hepatocellular carcinomas were also studied for comparative purposes. In all of these neoplasms the diagnosis of endocrine tumor was confirmed by immunohistochemical studies and the following information was recorded: age, sex, radiological alterations, primary site of the NET, and follow-up. The following histological data were also recorded: fibrotic stroma associated or not with the neoplastic cells, growth pattern, form of the cells, cellular size, mitotic figures, nucleomegaly, apparent nucleoli, chromatin in salt and pepper, plasmacytoid cells, intranuclear inclusions, and biliary pigment.In conclusion, these characteristics were common in metastasized neuroendocrine tumors: extensive stro-mal fibrosis, slight to moderate atypia, hyperchromatic nuclei, plasmacytoid cells, and thin delicate strands of fibrovascular tissue supporting larger acinar groups of net cells. HCC had a more infrequent fibrotic stroma, moderate to marked atypia, and in some biopsies biliary pigment, intranuclear inclusions, and clear cells

Low grade urothelial carcinoma mimicking basal cell hyperplasia and transitional metaplasia in needle prostate biopsy

ABSTRACT Purpose The vast majority of urothelial carcinomas infiltrating the bladder are consistent with high-grade tumors that can be easily recognized as malignant in needle prostatic biopsies. In contrast, the histological changes of low-grade urothelial carcinomas in this kind of biopsy have not been studied. Materials and Methods We describe the clinicopathologic features of two patients with low-grade bladder carcinomas infiltrating the prostate. They reported dysuria and hematuria. Both had a slight elevation of the prostate specific antigen and induration of the prostatic lobes. Needle biopsies were performed. At endoscopy bladder tumors were found in both cases. Results Both biopsies showed nests of basophilic cells and cells with perinuclear clearing and slight atypia infiltrating acini and small prostatic ducts. The stroma exhibited extensive desmoplasia and chronic inflammation. The original diagnosis was basal cell hyperplasia and transitional metaplasia. The bladder tumors also showed low-grade urothelial carcinoma. In one case, the neoplasm infiltrated the lamina propria, and in another, the muscle layer. In both, a transurethral resection was performed for obstructive urinary symptoms. The neoplasms were positive for high molecular weight keratin (34BetaE12) and thrombomodulin. No metastases were found in either of the patients, and one of them has survived for five years. Conclusions The diagnosis of low-grade urothelial carcinoma in prostate needle biopsies is difficult and may simulate benign prostate lesions including basal cell hyperplasia and urothelial metaplasia. It is crucial to recognize low-grade urothelial carcinoma in needle biopsies because only an early diagnosis and aggressive treatment can improve the prognosis for these patients