Abstract
A 57-year-old woman presented with a tumor from childhood in the left postauricular region that increased gradually in size. She showed an elastic, hard, and moist red tumor in the left postauricular region at the first medical examination. Although it was diagnosed as syringocystadenoma papilliferum by biopsy, a sample taken at surgery showed atypical cells with acidophil cytoplasm as a solid nest or a papillary duct with necrosis. The patient was diagnosed with apocrine adenocarcinoma, and additionally with syringocystadenocarcinoma papilliferum because of pathologic similarity of syringocystadenoma papilliferum. Apocrine adenocarcinoma without a physiological apocrine gland is rare, and only 3 cases in the postauricular region have been reported in Japan. The frequency of recurrence and metastasis of apocrine adenocarcinoma is high, making continued observation important.[Skin Cancer (Japan) 2014 ; 29 : 201-205]
