Abstract

Gout is characterized by dysregulation of urate production and excretion, leading to deposition of monosodium urate crystals in skin and joints. Gout may be primary or secondary. Etiology of primary gout is multifactorial, with genetic susceptibility and environmental factors playing a role. Secondary gout has many causes, most common being impaired urate excretion in chronic kidney disease. Increased hematopoietic cell turnover may also lead to urate elevation, rarely manifesting as secondary gout. Herein, we describe a subacute presentation of tophaceous gout as a harbinger for underlying myeloproliferative neoplasm with profound thrombocytosis and JAK2 V617F mutation – an association that has not previously been reported in the literature. A 65-year-old patient with no prior history of gout presented to Dermatology clinic with several subcutaneous painful nodules on the fingers that appeared abruptly and were growing over several weeks. X-ray was negative for calcinosis but showed non-specific soft tissue swelling and possible joint erosion. Skin biopsy of a subcutaneous nodule was performed for definitive diagnosis and revealed intradermal crystal deposition, consistent with gout. Baseline blood work showed elevated urate and platelet count greater than 1,000,000/uL. The patient was referred to Hematology/Oncology and underwent bone marrow biopsy, which revealed hypercellular marrow with maturing trilineage hematopoiesis and erythroid/granulocytic dysplasia, consistent with myeloproliferative neoplasm. Genetic testing further identified a JAK2 V617F mutation. This interesting case highlights the importance of considering secondary causes of gout, including hematologic malignancy, in newly diagnosed or treatment refractory cases.