Sporotrichoid granuloma annulare-like dermatitis associated with systemic B-cell lymphoma

Importance: Granuloma annulare is typically a benign, self-limited disease. Atypical presentations have been reported in association with systemic disease, including malignancy. Such patients may require additional diagnostic studies to assess for underlying malignancy. We report a patient with extensive sporotrichoid granuloma annulare-like dermatitis in association with systemic B-cell lymphoma. Observations: An 83-year-old man with a three-year history of progressive sporotrichoid annular plaques and nodules on the arm developed ipsilateral retroauricular palpable lymphadenopathy, the latter consistent with B-cell lymphoma. Multiple skin biopsies of the plaques and nodules revealed granuloma annulare-like dermatitis. Lesions were unresponsive to intralesional and intramuscular corticosteroids, antibiotics, and antifungal agents, but rapidly improved following initiation of rituximab to treat his underlying lymphoma. Conclusions and Relevance: Atypical presentations of granuloma annulare including granuloma annulare-like dermatitis warrant evaluation for systemic malignancy in a subset of patients.