Case Report: Subcutaneous Buttock Nodule as Initial Presentation of Gout

Background: Gout is a chronic condition characterized by the formation of monosodium urate crystals that lead to inflammation and pain. Chronically high uric acid levels can form tophi, characterized by granuloma-like structures in the subcutaneous tissues causing inflammation and pain. Rarely, tophi can be the initial presentation of gout. Here we present the first case of a tophaceous buttock cyst as the initial presentation of gout. Case Presentation: A 41-year-old male presented with a subcutaneous fluid-filled cyst on the medial portion of the left buttock that became inflamed several times per month. He underwent excision of the lesion with dermatology, and subsequent dermatopathology revealed amorphous eosinophilic material within the dermis consistent with gout with granulomatous dermatitis. He then presented to the colorectal surgery department for persistent drainage from this cyst, and was found to have a sinus tract over the previous site of the cyst. He underwent anorectal exam under anesthesia and excision of left buttock sinus tract with primary closure. The patient recovered well without complications. Discussion: Tophaceous gout is typically seen in patients with poorly-controlled chronic gout. This case is representative of a growing number of patients with tophi as an initial presentation of gout. Potential risk factors for tophi as the initial presentation of gout can include chronic kidney disease and genetic risk factors linked to urate metabolism. Conclusion: This is the first reported case of initial presentation of gout as a tophus on the buttock, found on biopsy to be consistent with gout. Clinicians should be aware of gout in the workup of patients with subcutaneous nodules resembling tophi, including in unconventional anatomic locations such as the buttock and hip area.