Thumb-Sparing Surgery for Digital Papillary Adenocarcinoma: A Case Report

Abstract

Digital papillary adenocarcinoma (DPA) is a rare eccrine sweat gland tumor that often appears as a solitary, non-painful, gradually enlarging mass. Clinically, DPA presents considerable challenges due to its high likelihood of recurrence and its tendency to spread to the lymph nodes and lungs. This case report focuses on the surgical treatment of a unique case of DPA located on the dorsal thumb in a 46-year-old male. The patient initially underwent wide local excision with temporary wound coverage, and once final histopathological findings confirmed negative margins, a second procedure consisting of thumb interphalangeal joint fusion and first dorsal metacarpal artery flap coverage was performed. Eighteen months later, the patient continued to work in landscaping, performing the physically demanding tasks required by the job. This case demonstrates the feasibility of thumb preservation in the setting of soft tissue malignancy once negative margins are obtained.

Keywords: digital papillary carcinoma; hand tumor; thumb reconstruction; thumb-sparing surgery; wide local excision.

Figure 1. Clinical photographs

The left dorsal thumb mass had a soft consistency when palpated.

Figure 2. Imaging test results

A: Posteroanterior; B: Lateral X-ray of the left thumb; C: Axial; D: Sagittal T2 fat suppression MRI of the left thumb showing an exophytic mass centered at the level of the interphalangeal joint.

Figure 3. Incisional biopsy results

A: Gross characteristics of the tumor were consistent with numerous fragments of friable, tan to red soft tissue aggregates; B: Low-power hematoxylin and eosin stain of the completely excised digital papillary adenocarcinoma tumor.

Figure 4. Wide excision procedure details

A: Planned excision of the mass with 1 cm margins; B: Dorsal thumb after removal of the mass with complete excision of the extensor pollicis longus, dorsal capsule, and collateral ligaments; C: The excised mass with an orientation suture; D-E: Integra coverage of the dorsal thumb to prevent desiccation of the exposed phalanges, along with thumb interphalangeal joint pinning as the joint was unstable.

Figure 5. Second-stage reconstructive surgery

A: Once margins were confirmed to be negative, a second-stage reconstructive surgery involving thumb interphalangeal joint fusion and FDMA flap coverage was performed; B: Bolster in place over the index finger skin graft site and a viable thumb flap three days post-operatively; C: Radiographic appearance of the fusion construct. FDMA: first dorsal metacarpal artery.