Primary diagnosis of Whipple's disease in bone marrow.

Whipple's disease (WD) is a chronic systemic inflammatory disease of infectious origin caused by Tropheryma whipplei (TW). Abdominal pain and recurrent diarrhea are usually the main symptoms leading to the suspicion of a primary bowel disease. Systemic manifestations can mimic hematologic disorders. A 49-year-old man presented with fever, weight loss, long-standing arthralgia, and diarrhea. A duodenal biopsy was unremarkable. Bone marrow histology provided no evidence of a malignant hematological disorder but revealed noncaseating granulomas. TW was detected in the bone marrow trephine by polymerase chain reaction. This is the first report to describe TW-associated granulomatous myelitis as the initially recognized organ manifestation of WD, proven at the molecular level. This observation is relevant for the differential diagnosis of patients with systemic symptoms and granulomatous diseases affecting the bone marrow, emphasizing that WD should be considered in cases of unexplained granulomatous myelitis, even when small bowel biopsy specimens are negative.