Spread of Squamous Cell Carcinoma From the Thumb to the Small Finger via the Flexor Tendon Sheaths

We report the development of metastatic squamous cell carcinoma at the tip of the small finger following the development of a thumb distal phalanx squamous cell carcinoma caused by chronic osteomyelitis. The spread of hand infections from the flexor tendons of the thumb to the small finger through a tendon sheath connection at the wrist is a well-described phenomenon. The evidence from this case suggests that the spread of the squamous cell carcinoma from the tip of the thumb to the tip of the small finger occurred in a similar fashion. This information is important in understanding how malignant tumors spread in the hand and wrist, and it might influence the management of such tumors.