Co-occurrence of apocrine adenocarcinoma and invasive mammary-type ductal carcinoma in extramammary Paget disease of the axilla

Extramammary Paget disease (EMPD) is an uncommon malignancy that occurs in apocrine gland-rich areas of the body. EMPD of the axilla is rare, but a few cases have been reported. Some cases of EMPD have been reported with underlying apocrine adenocarcinoma; rarely, mammary-type ductal carcinoma can accompany EMPD. Here, we report a very rare case of EMPD with apocrine adenocarcinoma and invasive mammary-type ductal carcinoma. A 55-year-old woman was referred with a brownish pigmented plaque accompanying an area of ulceration in the left axilla. A preoperative biopsy indicated Paget disease, and an additional evaluation was performed to determine whether it was of primary or secondary origin. A wide excision was made, and the axilla was reconstructed using a thoracodorsal artery perforator flap. The biopsy showed apocrine adenocarcinoma and invasive mammary-type ductal carcinoma with pagetoid spreading. The patient had no evidence of recurrence or other postoperative complications.