Pathology Discovery ISSN 2052-7896 | Volume 2 | Article 6 Case report Open Access Salivary duct carcinoma: a case report with cytological and pathological features Kuniaki Hirai 1 , Naomi Kawaguchi 1 , Kyoko Nambu 1 , Asuka Sekiya 1 , Toshimasa Sakakima 2 , Masashi Matsuyama 1 , Fumimasa Etori 1 , Yoichi Yokota 3 , Hiromichi Shirato 3 , Naoki Watanabe 1 , Takafumi Naiki 2 , Tetsuya Yamada 4 and Takuji Tanaka 1,5* Abstract A 55-year-old Japanese man presented with rapidly growing tumor in the left parotid region without any symptoms. Based on the fine-needle aspiration cytology report of parotid epithelial malignant tumor (suggestive of salivary duct carcinoma), the left parotidectomy was performed. Histopathology and immunohistochemistry examinations revealed features of salivary duct carcinoma. Although salivary duct carcinoma comprising a small proportion of salivary gland tumors and is known to be aggressive, he is free from recurrence and metastases 36 months after the surgery and radiation therapy. Keywords: Salivary duct carcinoma, parotid gland, fine-needle aspiration cytology, histopathology, immunohistochemistry © 2014 Tanaka et al; licensee Herbert Publications Ltd. his is an Open Access article distributed under the terms of Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0). his permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Introduction Salivary duct carcinoma is a rare malignant epithelial tumor, which accounts less than 1% of epithelial salivary gland neo- plasms [1]. Seventy-five percent of salivary duct carcinomas occur in the parotid gland [1]. The peak incidence is in the seventh decade of life, and its occurrence in patients under age50 year is uncommon [1]. Because of similar histologic features, salivary duct carcinoma is often compared to ductal carcinoma [2], atypical ductal hyperplasia [3,4] of the breast, but the majority of patients are men. This malignancy is one of the most aggressive salivary gland malignancies [1]. Local invasion, frequent lymphatic and hematogenous metastasis, and poor prognosis characterize the biologic behavior of this malignancy. Because of its low incidence [1], the cytological and patho- logical features have not been elucidated sufficiently. This case report illustrates both the cytological and pathological features of salivary duct carcinoma that developed in a Japanese adult male. Case presentation On June 9, 2011, a 55-year-old man presented our hospital with a progressively growing tumor mass on the left side of whis neck. He had no history of diseases. Physical examination re- vealed a single painless, firm, and mobile 3 cm mass in the parotid area. Facial nerve function was intact. At presentation, the results of routine serum biochemistry tests were normal, with the exception of the level of total bilirubin (1.5 mg/dl), blood sugar (118 mg/dl). Computed tomography (CT) scan showed a tumor mass (2.4 cm in diameter) almost entirely replacing the left parotid gland (Figure 1). Fine-needle aspiration cytology from the parotid tumor showed many epithelial tumor cells. They are arranged in cohesive clusters, which have a cribriform architectural pattern (Figure 2a). Indivi- dual tumor cells are scattered at the periphery of the cellular clusters. Tumor cells are round to polygonal with abun-dant and finely granular cytoplasm. They have medium to large, mode- rately pleomorphic and hyperchromatic nuclei with granular chromatin (Figures 2b and 2c). Based on the cytological findings, we diagnosed this tumor as parotid epithelial malignant tumor (suggestive of salivary duct carcinoma). The left parotidectomy was performed in July 20, 2011. As shown in Figure 3a, a nodular tumor (2.8 cm in diameter re- placed the parotid gland. Cut-surface of the resected tumor was yellowish white, unencapsulated, and poorly circumscribed *Correspondence: takutt@gmhosp.gifu.gifu.jp 1 Department of Diagnostic Pathology and Research Center of Diagnostic Pathology, Gifu Municipal Hospial, 7-1 Kashima-cho, Gifu City, Japan. 2 Department of Central Laboratory, Gifu Municipal Hospial, 7-1 Kashima-cho, Gifu City, Japan. 3 Department of Otolaryngology, Gifu Municipal Hospial, 7-1 Kashima-cho, Gifu City, Japan. 4 Department of Diagnostic Pathology, Kizawa Memory Hospital, 590 Shimofurui, Frui-machi, Minokamo City, Japan. 5 Department of Tumor Pathology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu City, Japan. CrossMark ← Click for updates