Primary Cutaneous Apocrine Adenocarcinoma of the Axilla in Klinefelter’s Syndrome: A Case Report

Abstract

Background: Primary Cutaneous Apocrine Adenocarcinoma (PCAA) is a rare cutaneous malignancy that arises from areas rich in apocrine glands, particularly the axilla. There are less than 200 cases described in the literature. However, none has been reported in patients with Klinefelter syndrome, who are known to have an increased risk of breast cancer, Case Presentation: We present a 66-year-old man with a significant family history of breast cancer who developed a right axillary mass initially thought to be hidradenitis suppurativa. On physical examination, he had bilateral gynecomastia. Laboratory workup was significant for hyper-gonadotrophic hypogonadism. Mammography showed bilateral gynecomastia with no radiologic evidence of malignancy in the breast, while magnetic resonance imaging of the breast revealed two suspicious masses seen in the right breast. Excision biopsy of the right axillary mass revealed a high-grade invasive adenocarcinoma involving the dermis and subcutis; the cells had prominent nucleoli vesicular chromatin pattern and voluminous eosinophilic cytoplasm consistent with primary cutaneous apocrine adenocarcinoma. Immunohistochemistry was positive for GATA-3, GCDFP-15, E-cadherin, ER Positive, PR negative, HER 2 by IHC 3 +, and androgen receptor-positive 100 %. Positron emission tomography showed mildly hypermetabolic asymmetric gynecomastia, right greater than left, but no abnormal hypermetabolic activity to suggest malignancy. Karyotype confirmed 47 XXY chromosomes which on. The patient underwent bilateral mastectomy due to his preference; excised breast tissue was negative for malignancy. Conclusion: We presented the first case report of PCAA of axillary in Klinefelter syndrome. Awareness of this association and differentiation from breast carcinoma should be undertaken.