Recurrent infantile inflammatory myofibroblastic tumor of mesentery––Case report and review of imaging findings

Abstract

Inflammatory myofibroblastic tumors (IMT) are rare soft tissue tumors of intermediate malignant potential with tendency for local recurrence. Although they can occur at all age groups, occurrence in infants is extremely unusual and their imaging characteristics are not well described. A 3-month-old female infant presented with gradually progressive abdominal distention without any fever or weight loss. She had a large ill-defined homogenous hypodense lesion of size 8.4 × 11.4 × 11.3 cm (APxTraxSag) in the abdomen showing mild delayed post contrast enhancement. She underwent exploratory laparotomy with gross total excision of mesenteric mass, histopathology of which was suggestive of IMT. She had recurrence within 6 months of complete resection with a well-defined heterogeneously enhancing lesion of size 1.8 × 1.8 × 2.3cm (APxTraxSag) in right paravesical region abutting the bladder without invasion with a similar lesion of size 4.4 × 2.1 × 3 cm (APxTraxSag) in left subdiaphragmatic region abutting superior surface of spleen (no invasion). Since, surgery in our patient would have entailed splenectomy and partial cystectomy, systemic therapy with ceritinib (anaplastic lymphoma kinase [ALK] inhibitor) was planned for her with which she had a near complete response after 2 months. A high index of suspicion is required to differentiate IMT from other common causes of mesenteric masses in children and role of radiologist is quintessential in this regard. Local recurrence with abutment but without invasion of surrounding structures points to the intermediate malignant pathology of IMT and may provide a clue to diagnosis. Systemic therapy is effective in patients who are ALK positive and destructive surgery should be avoided.

Inflammatory myofibroblastic tumor of the bladder: Computed tomographic features

“…IMT is a rare tumor with intermediate biological potential. It is characterized by irregular proliferation of spindle cells in a mucoid to the collagenous stroma, inflammatory infiltration mainly composed of plasma cells and lymphocytes, and occasional mixing of eosinophils and neutrophils (12). Since the first description of IMT in 1939, the understanding of its biological and clinical characteristics has undergone significant changes (9).…”

Mesenteric inflammatory myofibroblastic tumor mimicking acute appendicitis: A case report

“…Other sites where IMTs may arise include the pelvis, head and neck region, trunk, extremities, and skin [ 4 , 5 ]. Majority of patients with such IMTs present with an abdominal mass without other symptoms, however, a few IMTs may present with an acute abdomen as described above and some may also present with features of systemic inflammatory response syndrome [ 9 ]. Generally, the masses are nodular or globular and often with a myxoid background on gross examination.…”

“…Thus, surgical treatment remains the cornerstone of management of various IMTs [ 13 ]. Despite this, incidence of local recurrence is reported to be 1 in every 4 cases ranging from 15 to 37% especially in the mesentery [ 9 , 14 ].…”

An extremely rare case of malignant jejunal mesenteric inflammatory myofibroblastic tumor in a 61-year-old male patient: A case report and literature review

“…Giant cells ( 6 ), ganglion-shaped tumor cells ( 29 ), and cells with elongated and globular nuclei ( 65 ) were significantly correlated with the recurrence of IMT. Furthermore, pleomorphism contributed to IMT recurrence ( 5 ). Two patients died following the recurrence of mesenteric IMT; in both cases, ganglion-shaped tumor cells were present.…”

“…IMT has been reported in almost all body and soft tissue visceral organs ( 3 , 4 ). Most recorded cases were in the lung, followed by the mesentery and the omentum ( 5 , 6 ). IMT has also been known as inflammatory pseudotumor, plasma cell granuloma, omental mesenteric myxoid hamartoma, and inflammatory fibrosarcoma.…”