Lopez Jonathan J, Chen Beiyun, Ghosh Karthik, Peters Margot S
*Department of Dermatology, Mayo Clinic, Rochester, MN; †Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN; ‡Department of Internal Medicine, Mayo Clinic, Rochester, MN; and §Departments of Dermatology and Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN.
Am J Dermatopathol. 2016 Oct;38(10):e144-6. doi: 10.1097/DAD.0000000000000582.
Malignant proliferating tricholemmal tumor (MPTT) is a rare adnexal neoplasm most commonly located on the scalp. We a 62-year-old woman who presented to her local physician with a palpable but not visible nodule of the left breast, initially diagnosed as squamous cell carcinoma. Histopathological evaluation of the reexcision specimen incidentally revealed ductal carcinoma in situ. On referral to our institution, the skin biopsy specimen was reviewed and interpreted as a low-grade MPTT. This patient and 2 previously reported cases of MPTT involving breast skin highlight presentation of a rare tumor at an unusual site and the potential for misdiagnosis as squamous cell carcinoma. Reexcision provided the unexpected benefit for our patient of early diagnosis of ductal carcinoma in situ not revealed by imaging.
恶性增殖性毛鞘瘤（MPTT）是一种罕见的附属器肿瘤，最常见于头皮。我们报告一名62岁女性，她因左乳可触及但不可见的结节就诊于当地医生，最初被诊断为鳞状细胞癌。再次切除标本的组织病理学评估偶然发现原位导管癌。转诊至我们机构后，皮肤活检标本经复查被诊断为低级别MPTT。该患者以及之前报道的另外2例累及乳腺皮肤的MPTT病例，均凸显了这种罕见肿瘤在不寻常部位的表现以及被误诊为鳞状细胞癌的可能性。再次切除手术意外地使我们的患者得以早期诊断出影像学未显示的原位导管癌。
