Apocrine sweat gland carcinoma C44.-

The apocrine sweat gland carcinoma is an extremely rare tumor entity, of which about 50 cases have been described, about 14 of them with distant metastases (Wauer U et al. 2017). The tumour is closely related embryologically to hair follicles and sebaceous glands.

All sweat gland carcinomas together account for about 0.005% of all malignant skin tumours (Floros P et al. 2014).

Mainly in the axillary region

Painless soft tissue node of varying size (2.0-3.0 cm) in the axilla, which is clinically diagnosed as an epidermoid cyst or enlarged lymph nodes and is ultimately a random finding.

It is often difficult to differentiate between apocrine cutaneous carcinoma and skin metastasis of apocrine breast cancer because both tumor entities have similar histological characteristics and overlapping immunohistochemical profiles. For example, all apocrine sweat gland carcinomas express the marker GCDFP15, a glycoprotein that is otherwise typical for breast carcinomas. Furthermore, CEA and the EGF receptor. Further markers are adipophilin (36% of cases), the androgen receptor and cytokeratin 5/6. The detection of oestrogen or progesterone receptors plays a role for a possible anti-hormonal therapy approach with tamoxifen.

In the metastasized state, systemic chemotherapy with carboplatin and paclitaxel (Miller DH et al. 2015) or epirubicin and cyclophosphamide i.v. followed by fluorouracil. In the case of proven positive estrogen receptor status, treatment with tamoxifen. Larger tumour volumes can be irradiated percutaneously. If a mutation in the PTCH1 gene is detected, Vismodegib, a so-called hedgehog signaling pathway inhibitor, can be treated in the same way as in advanced basal cell carcinoma (Wauer D et al. 2017).

Local resection of the primary tumor with wide tumor-free resection margins. If necessary, follow-up radiation with a target volume of 50.4Gy (5x1.8Gy/week)

Apocrine sweat gland carcinomas typically have an aggressive course with an early tendency to lymphogenic metastasis. Late metastasis occurs in bone, lung pleura and rarely in visceral organs. The median survival decreases from 55 to 33 months in case of detection of lymph node metastases and from 55 to 33 months in case of distant metastases to 14.5 months (Miller DH et al. 2015).

1. Floros P et al (2014) A rare case of pectoral hidradenocarcinoma and brief review. Internet J Surge 26: 1-4
2. Miller DH et al (2015) Management of Metastatic Apocrine Hidradenocarcinoma with Chemotherapy and Radiation. Rare tumors 7: 6082.
3. Wauer U et al. (2017) Apocrine sweat gland carcinoma of the axilla with atypical course. A very rare malignant tumor entity and its interdisciplinary treatment. Dermatologist 68: 831-834