Association between Erdheim-Chester disease, Hashimoto thyroiditis, and familial thrombocytopenia.

A 28-year-old woman presented with progressive proptosis of the left eye. She had a history of familial thrombocytopenia and Hashimoto thyroiditis. CT of the orbits demonstrated a bilateral diffuse intraconal and extraconal infiltration. Biopsy from the left intraconal area revealed the typical histopathology of xanthogranuloma with a mixture of foamy histiocytes, Touton giant cells, and eosinophils. Systemic examination revealed a mediastinal and retroperitoneal infiltration with a focal lesion in the left kidney. A biopsy of the retroperitoneal area showed histopathology identical to that of the orbital lesion. A review of the literature indicated that the association between non-Langerhans histocytoses and immunologic dysfunctions is not uncommon. We hypothesize that Erdheim-Chester disease may be linked to an abnormal interaction between T-lymphocytes and macrophages similarly to the macrophage activation syndromes.