Aggressive digital papillary adenocarcinoma
ADPA; digital papillary carcinoma; aggressive papillary adenoma (older term — now obsolete; all are now considered carcinomas)
Aggressive digital papillary adenocarcinoma is a rare sweat-gland adenocarcinoma virtually confined to the volar surfaces of the distal fingers, toes, palms and soles of middle-aged and elderly adults. Despite a deceptively benign clinical appearance — typically a slowly enlarging, painless, skin-coloured nodule — it has marked metastatic potential, with up to 40% of cases recurring locally and 15–40% developing pulmonary metastases (the lung is by far the commonest distant site). Wide local excision or ray/distal-phalanx amputation with histological clearance plus sentinel-lymph-node biopsy and surveillance imaging of the chest are the cornerstones of management. The 2000 series by Duke and colleagues abolished the previous distinction between "adenoma" and "adenocarcinoma" — all such tumours are now considered carcinomas because of their metastatic risk; Suchak and colleagues (2012) subsequently questioned the prefix "aggressive".
Clinical features
- Slowly enlarging, painless, skin-coloured to red dermal/subcutaneous nodule.
- Almost always on the volar (palmar/plantar) surface of a digit (~80%) — most often the finger, then thumb, toe and palm.
- Median age 50; M:F ~2:1.
- Often misdiagnosed as ganglion, epidermoid cyst, foreign-body granuloma or fibroma — diagnostic delay common.
- May ulcerate or fix to deeper structures (tendon, joint, bone) when long-standing.
Histology
- Multinodular dermal proliferation of glandular and tubulo-papillary structures with intraluminal papillary projections.
- Cystic spaces with eosinophilic secretion.
- Variable cytological atypia, mitoses and necrosis.
- Lymphovascular invasion is a particularly adverse feature.
- Immunohistochemistry: CK7+, EMA+, CEA+; S100 variable.
- Differential: metastatic adenocarcinoma (lung, breast, GI) — clinical history and imaging essential.
Management
- Wide local excision with ≥1–2 cm margins is rarely feasible on a digit; ray amputation or distal phalanx amputation is the most common definitive procedure.
- Sentinel lymph node biopsy strongly recommended given metastatic risk.
- Imaging — CT chest at diagnosis and at 6-monthly intervals for at least 2 years; MRI of the digit to assess deep extension.
- Adjuvant radiotherapy considered for incomplete margins or extensive disease where amputation declined.
- Pulmonary metastasectomy can be curative for oligometastatic disease — refer to thoracic MDT.
- Systemic therapy for widely metastatic disease — limited evidence; carboplatin/paclitaxel and immunotherapy reported.
Prognosis
Local recurrence 30–50% with conservative excision; ray amputation reduces this to <10%. Pulmonary metastasis 15–40% — most common cause of disease-specific death. Long-term surveillance for at least 10 years is essential, including 6–12-monthly chest CT for the first 2 years.
References
- Duke WH et al. Aggressive digital papillary adenocarcinoma — review. Am J Surg Pathol; 2000.
- Suchak R et al. Cutaneous digital papillary adenocarcinoma — clinicopathologic study. Am J Surg Pathol; 2012.
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