Immunohistochemical Characterization of Cardiac Myxoma, Glandular Variant, in a 75-Year-Old Man
Year: 2012
Type: article
Study design: Case Report
Abstract: Although cardiac myxomas are very rare (incidence, 0.5/million population/year), they accounts for 50% to 70% of primary cardiac tumors. Only 1% to 2% of these show glandular differentiation, a potential pitfall for practicing pathologists to misdiagnose it as metastatic adenocarcinoma. We report a case of a 75-year-old man who was scheduled for elective coronary artery bypass grafting owing to unstable angina. Preoperative transesophageal echocardiogram revealed a right atrial mass, which was removed at the same surgery. The specimen obtained is a right atrial mass, measuring 2.5 × 2.3 × 2 cm. The mass was fixed in formalin and processed for routine H&E sections. A battery of immunohistochemical and special stains were performed, with appropriate positive and negative controls, to characterize the tumor. Microscopically, the tumor on H&E sections showed rings, cords, and nests of glands (1%-2%) in the background of myxoid stroma (98%), with focal calcification and ossification. The glands were composed of ovoid cells with eosinophilic cytoplasm, indistinct borders, and round nuclei without atypia. These glands stained positively for pancytokeratin, CK&7, BerEP4, calretinin, and mucicarmine and were PAS-positive and diastase-resistant. The negative staining results of HMB-45, CK20, TTF-1, monoclonal CEA and PSA ruled out the differential diagnoses of melanoma and metastatic adenocarcinoma from colon, lung, or prostate. Glandular elements in a cardiac myxoma may mislead a pathologist to a malignant diagnosis of metastatic adenocarcinoma on a generally benign, curable tumor. Our extensive immunohistochemical characterization on glandular variant of cardiac myxoma with a review of the literature will aid practicing pathologists to correctly identify this entity and avoid misdiagnosis.
Authors: Seema Shroff, Ying Huang, Lucia Balos, Frank Chen
Institution: University at Buffalo, State University of New York
Language: English
Topic: Cardiac tumors and thrombi
Subfield: Cardiology and Cardiovascular Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2563379148