Ganglion cysts, soft-tissue masses that commonly occur about the wrist, are often excised without imaging or biopsy. In this article, we report a series of incompletely excised soft-tissue sarcomas about the wrist and offer an algorithm for their evaluation. We describe a series of 4 consecutive patients who each presented after incomplete resection of a soft-tissue sarcoma mistakenly diagnosed as a ganglion cyst. We also retrospectively review the cases of 7 patients with incompletely excised sarcomas of the wrist. Three of the 4 patients with sarcomas mistaken for ganglion cysts did not have prior magnetic resonance imaging (MRI), 3 of the 4 did not have an attempted aspiration, and all 4 did not have transillumination. Common atypical characteristics included ulna-based lesions (3/4), symptoms for less than 6 months (3/4), and no appreciable fluctuation in size (3/4). Functional outcomes for all patients were poor because of multiple surgical procedures, re-excisions requiring flaps, and need for additional adjuvant therapies. Dorsal wrist masses with atypical characteristics should be approached with caution. Transillumination and aspiration are 2 accessible, cost-efficient methods for evaluating these masses. If either test is abnormal, an MRI should be performed.