Recurrent Inflammatory Myofibroblastic Tumor of Sternocleidomastoid Muscle

Abstract

Introduction- Inflammatory myofibroblastic tumour (IMT) is a rare intermediate grade mesenchymal lesion with low metastatic potential and a high propensity for recurrence. Most commonly affected sites are lungs, abdomen and pelvis. Head and neck IMTs account for 5% of all IMTs with IMT of sternocleidomastoid muscle being exceptionally rare.

Case report - A 35 year old female presented with a nodular mass lesion over skin in the left infra auricular area. She had a previous history of swelling at the same site with excision done, and histopathological report revealed inflammatory myofibroblastic tumour. Radiological evaluation was suggestive of neoplastic etiology. Intraoperatively mass was seen over the sternocleidomastoid muscle infiltrating overlying skin.  Excision of mass was done along with superficial parotidectomy. Histopathological examination revealed ALK positive inflammatory myofibroblastic tumour of sternocleidomastoid infiltrating the superficial parotid gland.

Discussion - Inflammatory myofibroblastic tumours are extremely rare in head and neck region and have a tendency to recur. Complete resection is the treatment of choice and histopathological examination with IHC is confirmatory for diagnosis.