Low-grade Cribriform Cystadenocarcinoma: A Review of the Literature and Case Report.

Low-grade cribriform cystadenocarcinoma (LGCCC) is a rare tumor of the salivary gland that most often arises from the parotid gland. A 51-year-old man developed a small mass on the right parotid gland 5 years ago. A preoperative magnetic resonance image showed abnormal intensity, an atypical characteristic for such a tumor; therefore, the diagnosis was difficult. Thus, a superficial parotidectomy was performed as a total excisional biopsy to remove the tumor. Histopathological analyses revealed that the tumor was composed of a single cyst comprising cells containing mucosal fluid, with proliferation of large cells. Also, proliferation of the tumor epithelium showed a papillary cribriform pattern of proliferation with a partial ring form, and the tissue inside the tumor was replaced by a hematoma. Mild cellular atypia was observed. Immunostaining for S-100 was positive, and the Ki-67 ratio was <5%. These histopathological findings led to a diagnosis of LGCCC of the parotid gland. At 54 months after surgery, the patient has had no recurrence or facial palsy. LGCCC is a rare neoplasm of the salivary gland and is listed in the current World Health Organization classification (2005) as a variant of cystadenocarcinoma. This case suggests that a thorough preoperative examination can lead to better diagnosis of rare tumors, including LGCCC. Thus, if a plastic surgeon is to correctly diagnose and treat parotid grand tumors, including LGCCC, then a detailed preoperative examination, including imaging, a disease course review, a physical examination, and differential diagnosis, should be considered carefully.