The Applicability of a Keratin 7 Monoclonal Antibody in Routinely Papanicolaou-stained Cytologic Specimens for the Differential Diagnosis of Carcinomas

Abstract

The monoclonal antibody OV-TL 12/30, which detects keratin 7, was tested for its usefulness in cytologic diagnosis by reincubating previously Papanicolaou-stained slides. For this purpose malignant effusions of 73 patients with histologically confirmed cancers of the colon, ovary, mesothelium, breast, lung, esophagus, pancreas, urinary bladder, stomach, kidney, and prostate were used. All malignant cells from ovarian adenocarcinomas were positive, whereas malignant cells from colonic adenocarcinomas and malignant mesotheliomas were negative. Adenocarcinomas of gastric, renal, pancreatic, esophageal, and mammary origin demonstrated variable staining. Transitional cell carcinomas were positive, whereas squamous and small cell lung carcinomas were negative. Because OV-TL 12/30 does not react with normal and atypical mesothelial cells in these preparations, this reagent is a valuable tool in distinguishing benign mesothelial cells and adenocarcinoma cells. The authors' results demonstrate that this antibody is an excellent tool in the differential diagnosis of malignant cells in effusions and can be used in routinely stained cytologic specimens to determine primary tumor localization. In addition to its ability to distinguish between ovarian and colonic adenocarcinomas, its negativity in mesotheliomas may prove helpful in several diagnostic considerations.

Adenocarcinoma in Females Detected in Serous Effusions

“…Most breast adenocarcinomas were found to be positive in both studies: Ramaekers et al 18 reported only 11.25% (9/80) negative reactions, whereas in our series, 67.6% (48/71) were positive. Ovarian adenocarcinoma was CK7 positive in the series by Ramaekers et al, 18 with paraffin-embedded samples, and Baars et al, 2 with cytologic smears, whereas, in the present series, 63.5% (40/63) of the cases were also CK7 positive.…”

“…2,14,18 However, these patterns do not show an absolute relationship. Several discrepancies among reports have been attributed to some epitope generally hidden under normal conditions and aberrantly expressed in sporadic neoplastic lesions.…”

Cytokeratins 20 and 7 in the differential diagnosis of metastatic carcinoma in cytologic specimens

“…Staining procedures for anti-CK 20 and anti-CK 7 antibodies in cytospins and routinely Papanicolaoustained cytologic specimens have been published elsewhere. 21,22 In the present series, the seven metastatic colon tumor specimens were all fine-needle aspirations; five from liver metastases, one from an abdominal lymph node, and one from a sacral bone lesion. In all of these specimens, the anti-CK 20 antibody showed cytoplasmic staining which was generally intense but seen in a minority of the tumor cells.…”

Cytokeratin 7 and Cytokeratin 20 Expression in Epithelial Neoplasms: A Survey of 435 Cases

“…Its expression is often seen in the major categories of adenocarcinoma, including adenocarcinoma of the breast, lung, ovary, endometrium, thyroid, salivary gland, pancreas, and bile duct (21,25,26). However, there are circumstances in which the determination of CK 7 positivity is useful.…”