Infantile inflammatory myofibroblastic tumor of the small bowel: a case report

Inflammatory myofibroblastic tumors are rare, solid, intermediate-grade mesenchymal neoplasms that predominantly affect children and adolescents. Infantile cases are exceedingly rare. A 6-month-old female infant was referred to our institution with a history of abdominal pain, repeated non-bilious vomiting and pallor, with an abdominal ultrasound that revealed the presence of a large (120✕76 mm) left sided abdominal mass. Apart from recurrent attacks of vague abdominal pain, there were no features of small bowel obstruction. Peripheral blood smear revealed normochromic anemia with moderate thrombocytosis. Other investigations, including random blood sugar, renal and liver function tests, serum electrolytes, and coagulation profile, were all within normal limits. Abdominal computed tomography confirmed the presence of a large (10✕10✕9 cm), solid heterogeneously enhanced mass in the left suprarenal region, crossing the midline, with the suggestion of neuroblastoma. Exploratory laparotomy revealed a large lobulated mass at the antimesenteric border of the mid-ileum. Complete surgical resection was performed with free intestinal margins. Histopathological examination revealed myofibroblastic spindle cell proliferation with mild atypia and low mitotic activity admixed with inflammatory (lymphocyte and plasma cell) infiltration, arranged in hyper- and hypocellular area with myxoid stoma, features in favor of inflammatory myofibroblastic tumor. Immunohistochemistry confirmed the specimen was negative for anaplastic lymphoma kinase. Following surgical excision, the patient received no further adjuvant therapy and remained asymptomatic, with normal ultrasound findings on four successive bimonthly postoperative visits. Although rare, inflammatory myofibroblastic tumors should be considered in infants who have large abdominal tumors and abdominal pain.