Neoplasm Mimics of Rheumatologic Presentations: Sialadenitis, Ocular Masquerade Syndromes, Retroperitoneal Fibrosis, and Regional Pain Syndromes

This article reviews a group of miscellaneous malignant conditions that may mimic rheumatologic diseases. Primary salivary gland cancer as well as lymphoproliferative conditions such as lymphoma and IgG4 related syndromes should be considered when evaluating a patient with sialadenosis. Primary intraocular lymphoma and melanoma in adults as well as leukemia and retinoblastoma in children may present as idiopathic ocular inflammation and require a high index of suspicion. Retroperitoneal fibrosis may mimic lymphoma or a solid malignancy and poses diagnostic challenges. Regional pain syndromes, such as complex regional pain and carpal tunnel syndromes, may be a manifestation of cancer and amyloidosis respectively. Awareness of these rare mimics may serve in guiding diagnostic investigations.