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Int J Clin Exp Pathol 2012;5(3):254-259

Case Report
Pigmented adenoid cystic carcinoma of the ear skin arising from the epidermis: a case
report with immunohistochemical studies

Tadashi Terada

Department of Pathology, Shizuoka City Shimizu Hospital, Shizuoka, Japan

Received October 21, 2011; accepted March 12, 2012; Epub March 25, 2012; Published March 30, 2012

Abstract: Adenoid cystic carcinoma (ACC) in the skin is very rare; only about 60 cases have been reported. Herein presented is a case of
pigmented ACC arising from epidermis of the ear skin. An 85-year-old man presented black tumor of the right ear. Dermatologists’ diagnosis
was basal cell carcinoma (BCC). Large biopsy was obtained. The biopsy showed proliferation of atypical basaloid cells arranged in a
cribriform pattern. The tumor cells were continuous with epidermis, as if it arose from the epidermis. Focal areas show melanin deposition in
the tumor cells. Mucin stains showed that the tumor cells and tubular lumens contained acidic mucin. Immunohistochemically, the tumor cells
were positive for cytokeratin (CK) AE1/3, CK34BE12, CK5/6, CK7, CK14, p63, alpha-smooth muscle actin (ASMA), S100 protein, p53, Ki-67
(labeling 85%), KIT, PDGFRA and CD56. The tumor cells were negative for CK CAM5.2, CK8, CK18, CK19, CK20, EMA, desmin, CEA, HMB45,
CD10, CD34, neuron-specific enolase, chromogranin, synaptophysin, CDX2, MUC1, MUC2, MUC5AC and MUC6. HMB-positive and S100-
positive melanocytes were seen in a very few areas. Since characteristic cribriform pattern was recognized in the tumor and the tumor showed
epithelial markers, myoepithelial markers (CD14, p63, ASMA, S100 protein) and KIT, the pathological diagnosis of ACC was made. No distant
and lymph node metastasis is now seen. The patient will be treated by complete resection. The present cutaneous ACC was unique in that the
ACC arose from the epidermis, had melanin pigment, and occurred in ear skin.

Keywords: Adenoid cystic carcinoma, ear skin, pigmented, immunohistochemistry

Address all correspondence to:
Dr. Tadashi Terada
Department of Pathology, Shizuoka City Shimizu Hospital
Miyakami 1231 Shimizu-Ku, Shizuoka 424-8636, Japan.
Tel: 81-54-336-1111; Fax: 81-54-336-1315
E-mail: piyo0111jp@yahoo.co.jp