A Case of a Second Intermetatarsal Space Gouty Tophus with a Presentation Similar to a Morton’s Neuroma

Abstract

Non-infectious soft tissue lesions of the foot and ankle are relatively rare clinically. These include benign and malignant neoplasms, as well as non-neoplastic or pseudotumoral lesions such as ganglionic, synovial and epidermoid cysts, intermetatarsal and adventitious bursitis, inflammatory lesions like gouty tophi and rheumatoid nodules, Morton’s neuroma, and granuloma annulare.A 48-year-old male with a history of medically treated tophaceous gout presented with left foot neuropathic pain and paresthesia, in the setting of a well-circumscribed soft tissue lesion of the second intermetatarsal space, suspected to be a Morton’s neuroma. Magnetic resonance imaging (MRI) showed a 4.1 x 2.7 x 2.6 cm heterogeneous soft tissue mass containing multiple cystic areas. Excisional biopsy was performed and histologic examination revealed well-circumscribed nodules of amorphous material containing needle-shaped clefts, rimmed by histiocytes, and multinucleated giant cells consistent with a gouty tophus.This is the first case reported in the literature of an intermetatarsal gouty tophus causing neuropathic pain and paresthesia. While Morton’s neuroma is the most common cause of this presentation, this case illustrates that other pseudotumoral lesions, such as a gouty tophus, may present similarly, and should be considered in the differential diagnosis. While most cases of tophaceous gout can be adequately treated with urate-lowering therapy, surgery may be indicated for tophi that do not resolve with medical treatment based upon symptom severity, compression of nearby structures, and functional impairment.

Unusual Case of Gouty Arthritis of the Second Distal Interphalangeal Joint (Second Toe)

“…The incidence of gouty arthritis occurring in the second distal interphalangeal joint is extremely rare, with only one case being reported of a case of intermetatarsal space gouty tophi [ 6 ]. However, other presentations in different joints have been previously reported as secondary gouty arthritis to other disorders.…”

Presurgical Perspective and Postsurgical Evaluation of Morton's Neuroma and Other Nerve Lesions

“…Likewise, the presence of gouty nodules should also be considered, especially in men. 14 They are inhomogeneous but also predominantly hypointense on T2-weighted MR images.…”