Elham Mirzaian - Department of Pathology, Shariati Hospital, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
Shafighe Asgarikarchekani - Department of Pathology, Shariati Hospital, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
Ashkan Abdoli - Department of Pathology, Shariati Hospital, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran

Acinic cell carcinoma (ACC) is a low or intermediate-grade malignant epithelial neoplasm of the salivary glands that generally shows an indolent behavior. Most cases arise in the major salivary glands, especially the parotid gland. ACC is usually known as a low-grade malignant tumor; however, poorly differentiated and high-grade transformed variants have been reported and may have a tendency for late recurrence and metastasis.Our case was a ۴۹-year-old woman with a history of a right parotid rapidly growing mass lesion, which was cytologically diagnosed as monomorphic adenoma on fine-needle aspiration (FNA). Finally, the diagnosis of ACC with dedifferentiated components was reported followed by parotidectomy. After ۳۰ sessions of radiotherapy, she presented with hemifacial paresis. An imaging examination of the brain showed intracranial hemorrhage, and she underwent a craniotomy. We performed histopathological and immunohistochemistry (IHC) examinations and diagnosed metastatic ACC with the dedifferentiated components.Few studies have reported ACC cases with dedifferentiated components and aggressive behavior, and to the best of our knowledge, this is the first published English report from the Persian population.

Acinic cell carcinoma, Dedifferentiation, Metastasis, Neoplasm, Salivary Gland