Histoplasmosis with tenosynovitis of the hand and hypercalcemia mimicking sarcoidosis

We report on an otherwise healthy 47-year-old male who developed subacute tenosynovitis of the hand associated with night sweats and inguinal lymphadenopathy. He had a past history of granulomatous mediastinal lymphadenitis with positive histoplasmosis serology 11 years previously. Carpal tunnel exploration with biopsy demonstrated granulomatous inflammation. Granulomatous inflammation, hypercalcemia, and an elevated serum angiotensin converting enzyme (ACE) level suggested the diagnosis of sarcoidosis, however histoplasmosis infection could eventually be diagnosed. This unusual presentation of histoplasmosis underscores the fact that the diagnosis of sarcoidosis requires careful exclusion of other causes of granulomatous inflammation, particularly infectious agents. Even in the setting of an elevated ACE level and hypercalcemia, the possibility of an infectious etiology must be considered before establishing a diagnosis of sarcoidosis.