An 83-year-old male patient found a mass in his right axilla 1 year ago without redness, swelling, and ache. Until the tumor gradually increased to about 3cm in size, the patient went to the nearest hospital and underwent local tumor resection on October 26, 2020. Then he came to our hospital for further treatment. Imaging examinations such as CT, MRI and PET/CT showed no abnormal enhancement or mass in the breast, no enlarged lymph nodes in the right armpit, and no distant metastasis (Fig. 1). Postoperative pathology showed that there was a nodule with skin, 3cm in diameter. Histologically, poorly differentiated adenocarcinoma was found in subcutaneous fibrous tissue. The immunohistochemical staining of the infiltrative tumor cell showed positive immunohistochemical staining for anti-gross cystic disease fluid protein-15 (GCDFP-15), GATA-3, cytokeratin (CK), CK7, EMA, and negative for estrogen receptor (ER), progesterone receptor (PR), prostate specific antigen (PSA), CK20, CDX2, p504S, p63, P40, TTF-1, NapsinA, PLAP, Syn, CgA. The expression of HER2 was 2+ by immunohistochemistry and fluorescence in situ hybridization (FISH) showed no amplification, and Ki67 was 20% positive (Fig. 2). After combining the imaging examination, clinical physical examination and immunohistochemical index, the patient was finally diagnosed as accessory breast cancer.
Considering that the patient was old and had coronary heart disease and serious arrhythmia in the evaluation of cardiopulmonary function, no further lymphadenectomy and chemotherapy were performed. Finally, the patient was treated with intensity modulated radiation therapy (IMRT) with 6MV X-ray. The radiotherapy area included the right operation area, the right axillary lymph node drainage area and the right accessory breast area. The radiation dose 60Gy/30F in total. After more than 6 months of follow-up, the patient is healthy and free of symptoms.
A 66-year-old male patient was referred to the nearest clinic for further treatment because he accidentally found a 1.5cm mass in the left armpit, bulging and red in appearance, without pain and ulceration. After routine examination, left axillary tumor resection was performed on June 20, 2020 in the nearby hospital. When he came to our hospital, our imaging examinations demonstrated that there was no clear mass in bilateral mammary glands, no obvious enlarged lymph nodes in bilateral armpits, and no metastasis of other organs (Fig. 3). Histologically, the main component of this malignant tumor was adenocarcinoma cell, which tends to be sweat gland origin, co-existing with Paget’s cells. Strong positive immunostaining of GCDFP-15, GATA-3, CK, E-cadherin, P120-tcn and partial positive immunostaining of CK5/6, CK20, P53 were observed in sweat gland carcinoma and Paget's cells, whereas ER, PR, P53, Calponin, MelanA, S-100, HMB-45, MUC2 did not stain. The expression of HER2 was 2+ by immunohistochemistry and fluorescence in situ hybridization (FISH) showed amplification, and Ki67 was 20% positive. In addition, androgen receptor (AR) was 40% positive (Fig. 4). Based on these results, the patient was evaluated for evidence of sweat gland cancer associated with extramammary Paget’s disease.
Thirty days after local resection, the patient underwent extended resection of left axillary tumor and left axillary lymph node dissection. The pathology after operation displayed a small number of atypical cells under the mucosa of the left axillary tumor resection tissue, and no metastasis was found in the axillary lymph nodes (0/14). From September 4, 2020 to November 13, 2020, four cycles of TC (docetaxel and cyclophosphamide) regimen were used as adjuvant chemotherapy. So far, the patients were followed up in good health, no recurrence and metastasis.