Ductal eccrine carcinoma of the axilla: a diagnostic pitfall

Abstract

Ductal eccrine carcinoma (DEC) is a rare sweat gland carcinoma with ductular differentiation. Clinically, it is characterized by a slowly growing, hardened plaque or nodule predominantly located on the head and neck. Histologically, DEC shares similar features to invasive breast carcinoma, thus causing great diagnostic challenges. We report a 69-year-old woman who presented with a hardened plaque on the axilla. A skin biopsy was performed and metastatic invasive breast carcinoma could not be ruled out. Complete excision and further workup were subsequently conducted, leading to the diagnosis of estrogen receptor positive DEC with associated axillary lymph node metastases. The patient received adjuvant radiotherapy to the left axilla and was started on oral letrozole. She is disease-free 14 months after initial diagnosis.

Metastatic Ductal Eccrine Adenocarcinoma with Excellent Response to Immunotherapy

“…Of these, the cerebral metastasis proved more overt clinically, resulting in significant symptom burden and requiring two operative decompressions and adjuvant stereotactic radiotherapy. In the previous literature on DEA, high rates of distant metastasis have been reported, occurring in 40–50% of cases [2, 4]. These figures are higher than, but generally comparable to, the prognostic data for other eccrine carcinomas and for MCATs more generally [6].…”

“…Eccrine carcinomas typically present as slow-growing nodules, plaques, or ulcerative lesions, with the most common sites of disease the being lower extremities, head and neck and trunk. DEA appears to have a predilection for the head and neck [2, 4]. The diagnosis of eccrine carcinoma relies on histopathological analysis of biopsy or excision specimens.…”

“…In addition, regional and distant metastasis rates as high as 30% have been reported for these tumours [6]. For DEA specifically, while data are limited, the prognosis appears particularly unfavourable, with a 70–80% risk of local recurrence and 40–50% risk of distant metastasis [2, 4].…”

“…This involves either wide local excision or Mohs micrographic surgery to achieve negative resection margins [5]. Regional lymph node dissection is recommended only if there is clinical suspicion of nodal disease [2]. Radiotherapy is often utilised as an adjunct to resection in high-risk cases such as large tumours, close resection margins, or lymphovascular or perineural invasion [5].…”

Asymptomatic erythematous hardened plaque on the scalp

“…Clinical benefit with tamoxifen in hormone receptor positive DEC has been documented. Regarding prognosis, local recurrence is common (up to 80%) while metastases are rare . Our patient underwent complete excision and 6 months of tamoxifen therapy, and after 9 months of follow‐up, there was no evidence of recurrence.…”