Distinguishing Malignant Mesothelioma from Other Conditions

Mesothelioma News

New Ways to Approach Mesothelioma Diagnosis

May 5, 2003 — British researchers compared biopsies from patients with cancerous or malignant mesothelioma with those from patients with benign, but similar–looking conditions such as reactive mesothelial hyperplasia (increased production of normal mesothelial cell tissue). The object was to find a marker based on the cell cycle that would better identify malignant mesothelioma. They chose to experiment with the protein antibody MCM2 (also known as minichromosome maintenance protein), which has also been the subject of studies involving cervical cancer cells (Eur J Biochem 2003 Mar; 270(6): 1089–101).

The study looked at 33 identified cases of malignant mesothelioma and 36 cases of reactive mesothelial hyperplasia and reactive pleural fibrosis (Histopathology 2003 May; 42(5): 498–502). Mesothelioma biopsy samples involved sarcomatoid cells (closely packed cells of connective tissue) and epithelial cells (cells from the outer mucous or skin–like covering). The samples were stained to indicate the presence of MCM2. MCM2 counts were higher in epithelial and sarcomatoid mesotheliomas compared with reactive mesothelial hyperplasia and reactive pleural fibrosis. The researchers concluded that MCM2 may prove useful in diagnosing malignant mesothelioma.

Distinguishing malignant mesothelioma from reactive mesothelial hyperplasia has long been a problem, especially in small pleural biopsies. Another study also tried to find appropriate markers for mesothelioma. Antibodies to epithelial membrane antigen (EMA), were used to compare epithelial malignant mesothelioma biopsy samples with benign reactive mesothelial hyperplasia samples (J Pathol 1999 Oct; 189(2): 251–7). The results were promising, providing higher staining of EMA in the malignant mesothelioma samples. However, some weak staining occurred in reactive hyperplasia samples. Similar prior studies have been inconclusive.