Immunohistochemical characterization of glandular elements in glandular cardiac myxoma: Study of six cases

Back ground: Glandular cardiac myxoma has varying clinical presentation with uncertain histogenesis and debatable immunohistochemical profile. Glandular epithelial differentiations are rare phenomenon known to be present as an intrinsic component of the tumor. The origin of the glands has been attributed to epithelial differentiation of a totipotent cardiomyogenic precursor cells or the entrapped foregut rests in the tumor. Materials and Methods: Retrospective study includes six cases of glandular cardiac myxoma collected over a perior of 4 years. Sections were examined to define the histogenesis, histological and immunohistochemical profile of the glandular elements. Results: Incidence of glandular cardiac myxoma was 6.6% with a male to female ratio of 1:2.Mean age was 49.9 years. Left atrium was the commonest site. Five were sporadic and one was familial. Chest pain and dyspnea were the commonest clinical symptoms. Histologically all myxoma showed well formed glandular structures with typical myxomatous area. No atypia, mitosis or necrosis was identified in the glandular elements. Markers in six cases of glandular cardiac myxoma were immunopositive for CK7, CK 19, EMA, CEA, focally for E-cadherin while immunonegative for CK20, Chromogranin, Synaptophysin, calretenin, vimentin, B-catenin, TTF-1 and GCDFP-15 favoring enteric differentiation. Conclusion: Glandular cardiac myxoma is a rare entity which shows characteristics similar to those of classical cardiac myxoma with benign glandular elements showing enteric differentiation. Complete surgical excision is the treatment of choice with good prognosis. It is important to recognize this entity to avoid an erroneous diagnosis of metastatic adenocarcinoma.