Incidental discovery of desmoid-type fibromatosis encapsulating granular cell tumor in a neck mass

Multiple primary cancers are defined as primary malignant tumors of different histological origins in one person. Desmoid-type fibromatosis (DF) is an extremely rare, locally aggressive, connective tissue malignancy that can be rooted anywhere in the body with the most common sites being thoracic wall and extremities. In contrast, granular cell tumors are rare neoplasms derived from Schwann cells commonly found in the oral cavity, skin and gastrointestinal tract. Moreover, diagnosing a patient with two primary cell tumors has become more common and the challenge of treatment becomes the focus in clinical situations. However, findings of a mass containing DF encapsulated by a granular cell tumor. Currently, there are no established guidelines for this rare condition. This case report serves to raise awareness of these two uncommon primary tumors emerging in an idiosyncratic nature.