Apocrine tubular adenoma on the palm: A case report

Rationale:Tubular apocrine adenoma (TAA) is a very rare benign neoplasm of the apocrine gland. The typical anatomical locations are mostly hair-bearing areas, where normal apocrine glands are abundant.Patient concerns:We report the case of a 40-year-old patient with a tubular apocrine adenoma on a non-hair-bearing area.Diagnoses:Ultrasonography showed a 0.4-cm-sized hypoechoic nodule in the subcutaneous plane of the left palm at the fourth carpometacarpal joint level.Interventions:Surgical resection was performed and histopathological examination revealed lobules of well-differentiated dilated tubular structures at the dermis level.Outcomes:At 1 year of postoperative follow-up, the patient was completely recovered without signs of recurrence.Lessons:Diagnosis of TAA can be misleading due to its unusual location and inconspicuous appearance. Immunohistochemistry for epithelial membrane antigen and gross cystic disease fluid protein-15 is crucial for the proper diagnosis. Complete excision is recommended to prevent recurrence.