Background: A basal cell adenocarcinoma (BCAC) is a low-grade malignancy of the salivary glands. A BCAC of the minor salivary gland is a rare disease, which is extremely rare in the maxillary sinus without invading from the palate and buccal mucosa. The histopathological characteristics of a BCAC are similar to those of a basal cell adenoma (BCA). However, BCAC can be differentiated from BCA based on its tendency to invade surrounding tissues. Surgical resection is the first-line treatment for BCACs. We report a case of a BCAC arising from the maxillary sinus minor salivary glands in an 82-year-old man.
Case presentation: In 2016, the patient presented with recurrent epistaxis, and he was referred to our department because a tumor was found in his left nasal cavity. Gross resection using the Denker operation was performed. Histopathological examination revealed no surrounding tissue invasion; therefore, BCA was diagnosed.
In 2017, the recurrent lesion was resected using endoscopy as much as possible, and the histopathologic findings again revealed a BCA.
In 2019, he developed diplopia, frequent epistaxis, and buccal swelling. The recurrence of maxillary sinus tumor was shown again with invasion of surrounding tissues, and we presumed a clinical diagnosis of a left maxillary carcinoma (suspected BCAC). When we performed partial maxillary resection by the Weber–Ferguson incision, we found that the tumor had partially invaded the bone of the orbital floor; thus, the floor of the orbit and orbital fat were partially resected. Finally, the tumor was diagnosed as a BCAC.
Conclusion: We report a BCAC arising from the maxillary sinus. This is an extremely rare sinus tumor, and differentiation of BCAC and BCA is important from a clinical or histopathological examination. A partial maxillectomy with a Weber–Ferguson incision was required for complete resection. When a malignancy is suspected in the recurrent maxillary sinus tumor, it is important to have a wider surgical field than that of the previous surgery to ensure complete resection.