An Algorithmic Approach to the Diagnosis of Malignant Mesothelioma

Course Author:
Henry D. Tazelaar, MD
Consultant, Mayo Clinic, Scottsdale, AZ

MOC^[?]: MK
Intended Audience: Pathologists, Residents, Pathologist Assistants

The incidence of malignant mesothelioma continues to rise and diagnosis remains extremely difficult. This eCourse presents criteria for making a diagnosis of epithelial and sacromatous malignant mesothelioma and related topics. Numerous papers are published annually that highlight the use of specific antibodies potentially helpful in separating mesothelioma from other malignant pleural lesions. Yet, small sample size, clinical presentations that overlap with lung cancer, rarity of the entity in routine surgical pathology practice and the potential legal overlay in many cases complicate the diagnosis of mesothelioma. This eCourse emphasizes a cost-effective, practical approach to the diagnosis of mesothelioma. It relies heavily on the H & E morphology for determining which immunoperoxidase stains are the most useful for diagnosis including CK 5/6, calretenin, keratin, CEA, MOC 31, TTF-1 and estrogen receptor protein. Discussion includes early and subtle examples of epithelial and sarcomatous mesotheliomas and risk factors for mesothelioma other than exposure to asbestos. The differential diagnosis of mimics including metastatic lung cancer, pleural sarcomas and synovial sarcoma are illustrated with examples. In the case of synovial sarcoma, the uses of other antibodies such as CD 31, CD 34 actin and PCR in differential diagnosis are shown.

The ASCP designates these educational activities for a maximum of 2 AMA PRA Category 1 Credits™. Physicians should only claim credit commensurate with the extent of their participation in the activities.

These activities meet MOC Part II Lifelong Learning requirements. These activities meet MOC Part II Self-Assessment Module requirements.