Lesions of the Distal Phalanx: Imaging Overview

Abstract

Lesions of the distal phalanx often pose a radiological dilemma as the differential diagnosis is potentially broad. Particularly for lytic lesions, there is a concern whether an underlying primary tumor or a metastatic deposit is present. Bone tumors of the hand are infrequent when compared to soft tissue tumors, and those involving the distal phalanx are very rare. Lesions of the distal phalanx may arise secondary to benign or malignant pathologies and may reflect primary or secondary tumors. The most common benign lesion is an enchondroma while the most frequent primary malignant lesion is chondrosarcoma. Inflammatory, metabolic, autoimmune, and traumatic pathologies may also present with a wide spectrum of radiological changes involving the distal phalanx. It is these tumor-like mimics which can further complicate diagnosis. We hope to highlight distinguishing features between these entities, allowing the radiologist to generate a clinically useful differential diagnosis. Even though most lesions are benign, it is crucial to differentiate them as some may be the first presentation of more a systemic condition.