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Metastatic hidradenocarcinoma with demonstration of Her‐2/neu gene amplification by fluorescence in situ hybridization: potential treatment implications
Author(s) -
Nash Jason W.,
Barrett Terry L.,
Kies Merrill,
Ross Merrick I,
Sneige Nour,
Diwan A. Hafeez,
Lazar Alexander J. F.
Publication year - 2007
Publication title -
journal of cutaneous pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.597
H-Index - 75
eISSN - 1600-0560
pISSN - 0303-6987
DOI - 10.1111/j.1600-0560.2006.00570.x
Subject(s) - pathology , fluorescence in situ hybridization , medicine , breast cancer , cytokeratin , immunohistochemistry , biology , cancer , biochemistry , gene , chromosome
A 44‐year‐old man was referred for a right chest nodule of 3 months duration. A ‘benign’ nodule had been excised from this location 8 years prior. On examination, palpable nodes were noted in the right axilla. Radiographic studies were significant only for right axillary lymphadenopathy. Histologically, a nodular dermal proliferation composed of poorly differentiated epithelioid cells in nests and focally forming ducts with pseudopapillary architecture comprised the primary tumor. Features of a clear cell hidradenoma were noted focally. Immunohistochemical (IHC) analysis revealed reactivity for HMW cytokeratins, CK5 and CK7, p53, p63, CEA (focal), androgen receptor, EGFR, estrogen receptor (ER), MUC5AC, and strong/diffuse membranous staining for Her‐2/ neu . Negative stains included villin, TTF‐1, CDX2, S‐100 protein, vimentin, gross cystic disease fluid protein 15 (GCDFP‐15), mammoglobulin, and MUC2. A wide local excision and axillary node dissection was performed. Metastatic tumor involved nine of 28 nodes. Interphase fluorescence in situ hybridization (FISH) demonstrated chromosomal amplification of the Her‐2/neu locus within the tumor and a nodal metastasis. The patient has completed adjuvant and radiotherapy, including trastuzumab, and is asymptomatic. We believe this to be the first demonstration of Her‐2/neu amplification in a malignant skin adnexal tumor. In analogy to breast carcinoma, these findings suggest the applicability of trastuzumab for patients with metastatic adnexal carcinomas demonstrating Her‐2/neu amplification.