Value of P63 and CK5/6 in distinguishing squamous cell carcinoma from adenocarcinoma in lung fine-needle aspiration specimens.

The current FDA-approved standard of care for nonsmall cell lung cancer is Carboplastin/Taxol/Avastin based upon an impressive survival benefit; however, patients with squamous carcinoma (SQCC) cannot receive Avastin because of a 30% mortality rate due to fatal hemoptysis. In this study we evaluated the role of cytomorphology and immunohistochemistry in differentiating SQCC from adenocarcinoma (ADC) in lung FNA specimens. The case cohort included 53 FNA cases of nonsmall cell lung carcinoma with surgical pathology follow-up. All FNA specimens were reviewed independently by a panel of cytopathologists to differentiate between SQCC and ADC. The cell block material was available in 23 cases (11 ADC and 12 SQCC) to perform immunohistochemical stains for TTF-1, CK7, CK20, P63, and CK5/6. On surgical resection, 35/53 (66%) cases were diagnosed as ADC and 18/53 (34%) as SQCC. The number of cases classified correctly on the basis of cytomorphology was 66% for ADC and 53% for SQCC (combined accuracy 60%). By immunohistochemical staining, 14/23 (61%) cases expressed TTF-1. Nine cases were TTF-1 negative; eight of the TTF-1 negative cases (89%) were SQCC. Twenty-three cases expressed CK7 (87%); one ADC case (4%) showed focal CK20 positivity. Both P63 and CK5/6 expression was seen in 9/12 (75%) SQCC cases; none of the ADC cases showed this dual expression. Cytomorphology alone may not be able to stratify all cases of nonsmall cell lung carcinoma into ADC and SQCC in FNA specimens. The immune-panel of TTF-1, CK7, CK20, P63, and CK5/6 is useful in differentiating SQCC from ADC.

Endoscopic ultrasound-guided biopsies of pancreatic masses: comparison between fine needle aspirations and needle core biopsies.

Endoscopic ultrasound-guided fine needle aspiration (EUS-guided FNA) is a highly sensitive and specific method for diagnosing pancreatic masses. Alternatively, EUS-guided needle core biopsies (NCB) have also been introduced. We sought to determine efficacies of pancreatic EUS-guided FNAs and NCBs. Records of consecutive EUS-guided FNAs received over a 24-mo-period were reviewed. Cases with concurrent NCBs were selected for the study. The diagnoses from the two modalities were compared and designated concordant (CC) or discordant (DC). Of 252 cases, 52 had concurrent NCBs. The final diagnoses included primary and secondary tumors. Of the 52 cases, 29/52 (55.8%) were CC and 23/52 (44.2%) were DC. The sensitivities for FNAs and NCBs were 95.0% and 67.6%, respectively. Both modalities were 100% specific. Direct comparison between EUS-guided FNAs and NCBs demonstrated that the former are more sensitive for diagnosing pancreatic neoplasms, both primaries and metastases. There was no correlation between CC/DC cases and type of neoplasm.

Utility of CD138 (syndecan-1) in distinguishing carcinomas from mesotheliomas.

CD138 (Syndecan-1) is a transmembrane heparan sulfate proteoglycan present on the surface of plasma cells and epithelial cells. CD138 is also expressed in some hematopoietic neoplasms and has recently been observed in carcinomas. We characterized CD138 expression in cell-block preparations of fluids/effusions, focusing on the distinction between carcinoma and mesothelioma. One hundred formalin-fixed, paraffin-embedded cell-block sections of fluids/effusions consisting of 58 metastatic carcinomas, 24 mesotheliomas, 11 reactive mesothelial cell proliferations, 3 lymphomas, 3 metastatic sarcomas, and 1 metastatic melanoma were stained with a monoclonal antibody against CD138. CD138 staining was observed in 32/58 (55%) metastatic carcinomas and 2/24 (8%) mesotheliomas; all reactive mesothelial cells, lymphomas, sarcomas, and melanoma were negative. CD138 is a highly specific marker in the differential diagnosis of carcinoma vs. mesothelioma. Distinct membranous staining without background staining of most inflammatory cells makes CD138 an ideal marker for cell-block preparations of fluids/effusions. It should be an integral component of the epithelial-mesothelial antibody panel.