Search

The diagnostic value of glypican 3 (GPC3) immunostaining on needle biopsy specimens has not been well assessed. In this study, 120 liver needle biopsy specimens, including 46 from cirrhotic livers and 74 hepatocellular carcinomas (HCCs), were immunohistochemically examined for expression of GPC3. The results showed strong cytoplasmic and membranous staining in 36 HCCs (49%), among which 20 cases (56%) showed diffuse immunoreactivity. None of the 46 cirrhotic livers exhibited positive GPC3 immunostaining. The nonneoplastic liver tissues (cirrhotic or noncirrhotic) that were present in the majority of the HCC cases were also completely negative for GPC3 expression. These data demonstrate that GPC3 is a reliable immunohistochemical marker for the diagnosis of HCC on needle biopsy specimens when positive. However, the detection rate in our series seems lower than that reported in studies using resection specimens as the study materials. Our findings emphasize that GPC3 immunoreactivity can be focal and that negative staining should not be viewed as evidence to exclude the diagnosis of HCC in challenging needle biopsy specimens. [ABSTRACT FROM AUTHOR]

Germ cell tumors (GCTs), rare malignancies that occur in a wide range of locations and display variable histologic patterns, may pose diagnostic challenges. Glypican 3 (GPC3), a membrane-bound heparan sulfate proteoglycan, has been shown to be a novel diagnostic marker in testicular GCT. However, GPC3 expression in ovarian and extragonadal GCT has not been reported. We evaluated GPC3 immunoreactivity in GCTs from 63 patients (57 children and 6 adults), including 14 ovarian and 20 extragonadal primary GCTs and 8 metastases along with 21 primary testicular GCTs for comparison. All 33 yolk sac tumors (YSTs) and both choriocarcinomas were immunoreactive for GPC3. In contrast, a minority of immature (4/10) and mature (4/35) teratomas were positive. No positivity was seen in 6 embryonal carcinomas or 5 germinomas. GPC3 is differentially expressed in ovarian and extragonadal GCTs, with expression predominantly observed in YSTs and choriocarcinoma. [ABSTRACT FROM AUTHOR]

Genetic alteration of the von Hippel-Lindau (VHL) tumor suppressor gene has been linked to hereditary and sporadic clear cell renal cell carcinomas (RCCs). Inconsistent data on immunodetection of the VHL gene product (pVHL) in normal tissues and tumors have been reported. We immunohistochemically reevaluated the usefulness of a specific rabbit polyclonal anti-pVHL antibody in 531 cases of renal and nonrenal neoplasms and normal tissues. Positive immunostaining was observed in nearly 100% of primary renal neoplasms, 95% of metastatic RCCs, and 90% of clear cell carcinomas of the ovary and uterus. In normal tissues, positive immunoreactivity was observed only in renal tubules, exocrine pancreas, islets, and bile ducts. Western blot and reverse transcription-polymerase chain reaction confirmed the immunostaining results. These data indicate that this anti-pVHL antibody is a useful marker in assisting diagnosis of metastatic RCC and may serve as a diagnostic marker for clear cell carcinomas of the ovary and uterus. [ABSTRACT FROM AUTHOR]