The β subunit of human chorionic gonadotropin lacks specificity for malignant cells in serous effusions

Abstract

The cytologic diagnosis of malignancy is frequently straightforward. For difficult cases, multiple immunostains and immunostain panels have been investigated without consensus. b-human chorionic gonadotropin (hCG) has been reportedly expressed in malignancies, but not in normal tissue. HCG also has been reported as a specific marker of metastases in serous fluids when detected with laboratory assays. We investigated the clinical utility of hCG in this cytologic setting. A total of 97 cases of benign and malignant effusions were studied. Each case was immunostained with monoclonal hCG using the avidin-biotin technique and diaminobenzidine as a chromogen. Additionally, a mucicarmine stain was performed on most cases. Cases were evaluated for hCG expression and mucin in a blinded fashion. After the cases were reviewed, the diagnoses were unblinded and staining patterns were evaluated. Of the 47 benign cases studied, 23 (49%) exhibited immunoreactivity to hCG in at least 5% of mesothelial cells present. In contrast, 28 of 44 (64%) adenocarcionomas exhibited a similar degree of immunostaining. In all, 21 (48%) of the adenocarcinomas were also positive for mucin; five of these mucin-positive cases were negative for hCG. The combination of mucin and hCG detected 33 of 44 (75%) adenocarcinomas. We conclude that hCG lacks the specificity for malignant cells to be of clinical use in effusion cytology.

Serum β-human chorionic gonadotropin as a tumor marker for malignant mesothelioma

“…Considering that nontrophoblastic tumors might stain positive for β-hCG in up to 20% of the patients [ [3], our case is the first case in whom serum β-hCG levels increased with disease progression and the peritoneal mesothelioma stained positive for β-hCG. This is possibly related to the sarcomatoid component of the tumor.…”

“…Moreover, in their report concerning 201 cancer patients including four cases with malignant mesothelioma, Zimmerman et al, reported that serous effusions from two out of four mesothelioma patients (50%) and twenty-eight patients out of forty-four adenocarcinoma patients (64%) stained positive for hCG and mucin. They concluded that β-hCG was not clinically useful for effusion cytology because of a low specificity [7]. In another study by Ugurman et al, pleural and serum β-hCG levels and their ratio were evaluated for discriminating benign and malignant pleural effusions.…”

“…In some studies, it was shown that β-hCG could also be used as a marker for tumors other than germ cell and trophoblastic origins. In a comprehensive review published in 1987, high β-hCG levels were detected in 20% of cancer patients whose tumors were not of trophoblastic or germ cell origin [3].…”

nm23 is expressed in reactive mesothelium and is not useful for detection of malignant cells in serous effusions

“…One hundred cases were selected from the archives of the Presbyterian Medical Center and the Hospital of the University of Pennsylvania from 1998 to 2003. Many of these cases have been reported previously (16)(17)(18)(19). Forty-four cases were diagnosed as benign reactive mesothelium; the remaining 56 cases were malignant.…”