J Korean Surg Soc.  2012 Jun;82(6):380-384.

A case of inflammatory myofibroblastic tumor originated from the greater omentum in young adult

• Kye BH
• Kim HJ
• Kang SG
• Yoo C
• Cho HM

Abstract

Inflammatory myofibroblastic (IMF) tumor is a rare solid tumor that often affects children. IMF tumors occur primarily in the lung, but the tumor may affect any organ system with protean manifestations. A 22-year-old woman was evaluated for palpable low abdominal mass that had been increasing in size since two months prior. Abdominal computed tomography showed a lobulated, heterogeneous contrast enhancing soft tissue mass, 6.5 x 5.7 cm in size in the ileal mesentery. At surgery, the mass originated from the greater omentum laying in the pelvic cavity and was completely excised without tumor spillage. Histologically, the mass was a spindle cell lesion with severe atypism and some mitosis. Immunohistochemistry for anaplastic lymphoma kinase-1 revealed that the lesion was an IMF tumor. Because of its local invasiveness and its tendency to recur, this tumor can be confused with a soft tissue sarcoma. Increasing physician awareness of this entity should facilitate recognition of its clinical characteristics and laboratory findings.

Keyword

Inflammatory myofibroblastic tumor; Spindle cell tumor; ALK-1; Omental mass

MeSH Terms

Child
Female
Humans
Immunohistochemistry
Lung
Lymphoma
Mesentery
Mitosis
Myofibroblasts
Omentum
Sarcoma
Young Adult

Figure

• 

  Fig. 1 Contrast-enhanced computed tomography scan of the abdomen in axial (A) and coronal (B). A lobulated and heterogeneous contrast enhancing soft tissue mass (arrow) originating from the ileal mesentery is seen.

• 

  Fig. 2 Specimen consists of a portion of tan-colored tissue, measuring 7.5 × 7.0 × 5.0 cm. Arrow indicates feeding vessel originated from greater omentum.

• 

  Fig. 3 Tumor shows well-circumscribed, whorled growth pattern (H&E, ×40).

• 

  Fig. 4 Tumor is composed predominantly of spindle or stellate-shaped cells with prominent inflammatory cells. Occasionally, ganglion-like cells (arrow) present (H&E, ×400).

• 

  Fig. 5 Immunohistochemical staining (×400) result for anaplastic lymphoma kinase-1 shows strong positivity of tumor cytoplasm (arrow).

Reference

1. Coffin CM, Watterson J, Priest JR, Dehner LP. Extrapulmonary inflammatory myofibroblastic tumor (inflammatory pseudotumor): a clinicopathologic and immunohistochemical study of 84 cases. Am J Surg Pathol. 1995. 19:859–872.

2. Kim SJ, Kim WS, Cheon JE, Shin SM, Youn BJ, Kim IO, et al. Inflammatory myofibroblastic tumors of the abdomen as mimickers of malignancy: imaging features in nine children. AJR Am J Roentgenol. 2009. 193:1419–1424.

3. Stringer MD, Ramani P, Yeung CK, Capps SN, Kiely EM, Spitz L. Abdominal inflammatory myofibroblastic tumours in children. Br J Surg. 1992. 79:1357–1360.

4. Mergan F, Jaubert F, Sauvat F, Hartmann O, Lortat-Jacob S, Revillon Y, et al. Inflammatory myofibroblastic tumor in children: clinical review with anaplastic lymphoma kinase, Epstein-Barr virus, and human herpesvirus 8 detection analysis. J Pediatr Surg. 2005. 40:1581–1586.

5. Sawant S, Kasturi L, Amin A. Inflammatory myofibroblastic tumor. Indian J Pediatr. 2002. 69:1001–1002.

6. Pecorella I, Ciardi A, Memeo L, Trombetta G, de Quarto A, de Simone P, et al. Inflammatory pseudotumour of the liver: evidence for malignant transformation. Pathol Res Pract. 1999. 195:115–120.

7. Sodhi KS, Virmani V, Bal A, Saxena AK, Samujh R, Khandelwa N. Inflammatory pseudotumor of the omentum. Indian J Pediatr. 2010. 77:687–688.

8. Saleem MI, Ben-Hamida MA, Barrett AM, Bunn SK, Huntley L, Wood KM, et al. Lower abdominal inflammatory myofibroblastic tumor -an unusual presentation- a case report and brief literature review. Eur J Pediatr. 2007. 166:679–683.

9. Gupta CR, Mohta A, Khurana N, Paik S. Inflammatory pseudotumor of the omentum: an uncommon pediatric tumor. Indian J Pathol Microbiol. 2009. 52:219–221.

10. Coffin CM, Hornick JL, Fletcher CD. Inflammatory myofibroblastic tumor: comparison of clinicopathologic, histologic, and immunohistochemical features including ALK expression in atypical and aggressive cases. Am J Surg Pathol. 2007. 31:509–520.