Systemic mastocytosis following mediastinal germ cell tumor: an association confirmed.

A 24-year-old man had a mediastinal embryonal carcinoma containing yolk sac foci. Combination chemotherapy with cisplatin, bleomycin, etoposide, and vinblastine was given, and the residual mass was then resected. Histology showed only necrotic cells. No other treatment was given. Two years later the patient presented with episodes of flushing and syncopes related to a systemicmastocytosis. Bone marrow examination showed a diffuse infiltration with large, atypical mast cells often with multilobulated nuclei. The patient suffered several episodes of cardiovascular collapse and died during one of these episodes, 8 months after the diagnosis of systemic mastocytosis and 40 months after the diagnosis of mediastinal tumor. Autopsy findings included the absence of mediastinal tumor and a diffuse liver and spleen mast cell infiltration. This was the second case with the similar clinicopathologic picture of two rare diseases being associated. This fact supports the hypothesis of a distinct entity, part of the mediastinal germ cell tumor/hematologic malignancy syndrome. The hypothesis of a cytokine secretion induced by mediastinal germ cell tumor supporting mast cell proliferation may be considered.