An eosinophilic fibrohistiocytic lesion of bone marrow in a patient with Hodgkin's disease. A potential for morphologic confusion

The eosinophilic fibrohistiocytic lesion of bone marrow (EFLBM) is characterized by collections of elongated “ fibrohistiocytic” cells in association with lymphocytes, eosinophils, and plasma cells. The fibrohistiocytic cells are mast cells, and many investigators include this lesion (EFLBM) as a localized form of mastocytosis. The etiology and clinical significance of these lesions remains unclear. The morphologic features of these lesions point to a wide differential diagnosis that includes Hodgkin's disease. Currently, however, there are no recorded cases of well‐defined Hodgkin's disease with these lesions. A case of Hodgkin's disease in which such lesions complicated the interpretation of serial bone marrows is reported. This case illustrates how the presence of these lesions could potentially influence therapeutic intervention.