Omental Inflammatory Myofibroblastic Tumor, Masquerading as Adnexal Pathology in a Child: A Case Report

Naveen Kumar; Priyanka Hegde; Vinay Prasad; Sundeep Kisku

doi:10.25259/KJS_22_2024

View/Download PDF

Buy Reprints

PDF

Translate this page into:

Case Report

2 (

); 25-27

doi:

10.25259/KJS_22_2024

Omental Inflammatory Myofibroblastic Tumor, Masquerading as Adnexal Pathology in a Child: A Case Report

Naveen Kumar^1,_{MCh (Paediatric Surgery)}, Priyanka Hegde¹_{MCh (Paediatric Surgery)}, Vinay Prasad¹_{MCh (Paediatric Surgery)}, Sundeep Kisku¹_{MCh (Paediatric Surgery)}

1Department of Paediatric Surgery, Christian Medical College, Vellore, India

*Corresponding author: Naveen Kumar, Department of Paediatric Surgery, Christian Medical College, Vellore, India nicksongerrald1129@gmail.com

Received: 2024-11-03, Accepted: 2024-12-09, Published: 2025-02-14

Licence

This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-Share Alike 4.0 License, which allows others to remix, transform, and build upon the work non-commercially, as long as the author is credited and the new creations are licensed under the identical terms.

How to cite this article: Kumar N, Hegde P, Prasad V, Kisku S. Omental Inflammatory Myofibroblastic Tumor, Masquerading as Adnexal Pathology in a Child: A Case Report. Karnataka J Surg. 2025;2:25–27. doi: 10.25259/KJS_22_2024

Abstract

An inflammatory myofibroblastic tumour (IMFT) is a rare neoplasm with unpredictable malignant potential occurring throughout the body. Omental IMFT is exceedingly rare, with fewer than 15 reported cases. We present a case of a 9-year-old female patient with a freely mobile pelvic mass, initially resembling an adnexal mass on imaging. The patient underwent tumour resection with omentectomy. Histopathological examination confirmed the diagnosis of omental IMFT. This case underscores the rarity of omental IMFT, particularly in paediatric patients, and its atypical presentation as an adnexal mass. The diagnostic challenges and implications for management are discussed.

Keywords

Children

Inflammatory myofibroblastic tumour

Pseudotumor

Show Related Articles from PubMed

INTRODUCTION

Inflammatory myofibroblastic tumour (IMFT), or Inflammatory Pseudotumor, is a rare neoplasm with variable malignant potential, primarily affecting children and young adults.^[1,2] IMFT has been reported in various locations, with a predilection for the lungs, mediastinum, and orbits. Intraabdominal IMFT typically involves the liver, stomach, bowel, and spleen. Exceptionally rare, omental IMFT has been documented in fewer than 15 global cases. Due to its rarity and nonspecific presentation, preoperative diagnosis poses significant challenges. We report a unique case of omental IMFT masquerading as an adnexal mass, highlighting diagnostic complexities and the crucial role of histopathological confirmation. This manuscript was prepared following the consensus-based clinical case reporting (CARE) guidelines.

CASE REPORT

A 9-year-old girl presented with a 4-month history of incidentally detected lower abdominal mass and loss of appetite without systemic symptoms. Clinical examination revealed a freely mobile, lower abdominal pelvic mass with no palpable lymphadenopathy. Laboratory tests, including haemoglobin, total leukocyte count, erythrocyte sedimentation rate (ESR), serum proteins, and tumour markers [CA-125, Alpha feto protein (AFP), and Beta human chorionic gonadotropin (HCG)], were within normal limits. Imaging studies (ultrasound and computed tomography (CT) showed a well-defined, heteroechoic, predominantly solid lesion (5.9 × 5.2 cm) in the left adnexal region [Figures 1 and 2]. Intraoperatively, a well-capsulated, vascularised, multilobulated hard tumour (4 × 5 cm) arose from the greater omentum [Figure 3] with mesenteric lymphadenopathy and minimal ascites. The histopathological evaluation confirmed IMFT, with immunohistochemistry (IHC) revealing diffuse strong staining for anaplastic lymphoma kinase (ALK) [Figure 4] and smooth muscle actin (SMA) [Figure 5], patchy moderate staining for desmin, and negativity for DOG1 and CD117. The patient underwent an omentectomy with tumour excision and mesenteric lymph node biopsy. Given the tumour’s benign nature, no further treatment was offered, and the patient is currently under surveillance.

Contrast-enhanced computed tomography—axial cut scan showing a well-defined, heteroechoic, predominantly solid lesion (5.9 × 5.2 cm) in the left adnexal region (white arrow).

Contrast-enhanced computed tomography—sagittal cut scan showing a well-defined, heteroechoic, predominantly solid lesion (5.9 × 5.2 cm) in the left adnexal region (white arrow).

Intraoperative image showing tumour arising from omentum (white arrow).

Histopathology—spindle cell populations with plasma cell infiltrate with the tumour cells showing cytoplasmic anaplastic lymphoma kinase (ALK) positivity (H&E, 10X).

Histopathology—spindle cell populations with plasma cell infiltrate with the tumour cells showing cytoplasmic smooth muscle actin (SMA) positivity (H&E, 40X).

DISCUSSION

IMFT is a rare, intermediate-biology tumour characterised by variable clinical presentations, posing significant diagnostic challenges.^[1] Initially considered benign, IMFT’s potential for recurrence and metastasis is well-documented, emphasising the need for accurate diagnosis and optimal management. IMFT can occur in various extrapulmonary locations, including the abdomen, liver, and omentum, and presents with nonspecific symptoms such as fever, weight loss, abdominal pain, and palpable masses. Abdominal IMFTs are frequently mistaken for malignant tumours, including peritoneal carcinomatosis, sarcoma, or lymphoma. Laboratory findings are nonspecific, and radiologic features overlap with malignant lesions.^[3] Histology and IHC are crucial for diagnosis. Histologically, IMFT is characterised by diffuse inflammation, prominent plasma cells, and positivity for actin and vimentin on IHC.^[4] The tumour’s cellular composition and immunophenotypic features are crucial for distinguishing IMFT from other malignant entities, such as sarcomas, lymphomas, and peritoneal carcinomatosis.^[5,6] Prognosis is influenced by features such as multifocality, retroperitoneal location, incomplete excision, and tumour size, while ALK positivity predicts lower metastasis risk.^[7] Treatment involves complete surgical excision of the tumour, which is the primary therapeutic approach. The role of radiotherapy and chemotherapy is limited, and their effectiveness is not well established. Regular follow-up is essential for detecting late recurrences, which can occur even years after initial treatment. Overall, IMFT’s rarity and nonspecific presentation underscore the importance of histopathological diagnosis and multidisciplinary management to ensure optimal patient outcomes.

CONCLUSION

Omental IMFT’s rarity and nonspecific presentation pose diagnostic challenges. Accurate histopathological diagnosis is crucial for optimal management and patient outcomes.

Author contributions

NK: Manuscript drafting and proof checking, read and approved; PH: Provided critical input, read and approved; VP: Data collection, read and approved; SK: Proof checking, read and approved.

Ethical approval

The Institutional Review Board has waived the ethical approval for this study.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

Use of artificial intelligence (AI)-assisted technology for manuscript preparation

The authors confirm that there was no use of artificial intelligence (AI)-assisted technology for assisting in the writing or editing of the manuscript and no images were manipulated using AI.

REFERENCES

Da M, Qian B, Mo X, Xu C, Wu H, Jiang B, . Inflammatory Myofibroblastic Tumors in Children: A Clinical Retrospective Study on 19 Cases. Front Pediatr. 2021;9:543078.
[CrossRef] [PubMed] [PubMed Central] [Google Scholar]
D’Cunha A, Jehangir S, Thomas R. Inflammatory Myofibroblastic Tumor of Common Bile Duct in a Girl. APSP J Case Rep. 2016;7:28.
[CrossRef] [PubMed] [PubMed Central] [Google Scholar]
García IV, Gutierrez AS, Guzmán SB, Viveros BA. Inflammatory Myofibroblastic Tumor in Pediatric Patients: Challenges in Diagnosis, Multidisciplinary Management, and Surgical Strategies. Egypt Pediatr Assoc Gaz. 2024;72:26.
[Google Scholar]
Gupta CR, Mohta A, Khurana N, Paik S. Inflammatory Pseudotumor of the Omentum: An Uncommon Pediatric Tumor. Indian J Pathol Microbiol. 2009;52:219-21.
[Google Scholar]
Kim SJ, Kim WS, Cheon JE, Shin SM, Youn BJ, Kim IO, . Inflammatory Myofibroblastic Tumors of the Abdomen as Mimickers of Malignancy: Imaging Features in Nine Children. AJR Am J Roentgenol. 2009;193:1419-24.
[Google Scholar]
Singhal M, Ramanathan S, Das A, Singh E, Bagga R, Khandelwal N. Omental Inflammatory Myofibroblastic Tumour Mimicking Peritoneal Carcinomatosis. Cancer Imaging. 2011;11:19-22.
[CrossRef] [PubMed] [PubMed Central] [Google Scholar]
Treissman SP, Gillis DA, Lee CL, Giacomantonio M, Resch L. Omental-Mesenteric Inflammatory Pseudotumor. Cytogenetic Demonstration of Genetic Changes and Monoclonality in one Tumor. Cancer. 1994;73:1433-7.
[CrossRef] [PubMed] [Google Scholar]