Myofibroblastoma: report of a rare entity in the pediatric population

Clinicopathologic evaluation of myofibroblastoma: A study in two hospitals

OBJECTIVE

To report various anatomic locations and clinical characteristics of pathologically proven myofibroblastoma in Koran patients.

METHODS

Pathologic reports of patients who underwent surgeries at two centers between April 2003 and March 2016 were retrieved from the electronic medical record system of the hospital. Pathologic reports were included after performing a search using the keyword "myofibroblastoma".

RESULTS

The cohort consisted of 11 subjects and included eight female and three male individuals. The patients' ages ranged from 9 to 66 years. Tumors were located in the vagina in three patients and presented in the breast in seven patients. One case presented with an abdominal mass. The tumors ranged in mean size from 4.0 to 53.0 mm. Despite a relatively long-term follow-up, no case had evidence of tumor recurrence.

CONCLUSION

We evaluated the various anatomic locations of pathologically proven myofibroblastoma in Korean patients. As an extremely rare tumor, physicians should pay special attention to differential diagnosis. Surgical resection is the preferred method for a cure, and the recurrence rate is extremely low.

Mammary-type myofibroblastoma of the psoas

Mammary myofibroblastoma is a rare, benign, mesenchymal neoplasm that was first described in the breast in 1987. However, extra-mammary-type myofibroblastoma (MTMF) was not described until 2001 as a distinct entity. We report a case of extra-MTMF arising from the retroperitoneum, which was encountered in our clinic. We also completed a review of the literature using PubMed in patients with extra-MTMF.

Myofibroblastoma of the mandible in a 3-year-old child

Myofibroblastoma is a rare benign tumor of the head and neck region, which is characterized by a large, rapidly growing, and destructive mass. A 3-year-old boy presented with an 8-week history of a rapidly growing swelling of the right mandible. Examination revealed a firm 13-cm mass occupying the entire right body and ramus of the mandible. The clinical and radiological features were suggestive of a sarcoma. An initial biopsy taken in the referring hospital was inconclusive, and the second biopsy showed a myofibroblastic neoplasm consistent with a desmoplastic fibroma. Progressive tumor growth necessitated a tracheostomy. Right hemimandibulectomy was performed, and the defect was reconstructed with free microvascular fibula flap. Histopathology and immunocytochemistry revealed a myofibroblastoma. This entity differs from other myofibroblasts and fibroblast tumors such as inflammatory myofibroblastic tumor (IMT), myofibroma, and desmoplastic fibroma. The child has been followed up for 2 years.

CONCLUSION

Differentiation between myofibroblasts and fibroblastic tumors as well as some malignancies can be challenging. Myofibroblastoma can behave as a malignant neoplasm, and the clinical distinction of this entity lies primarily in its recognition as a benign neoplasm.