Clinical Image

Gastric leiomyosarcoma: A common tumor in an uncommon location

Muhammad B Malik¹

Kanish Mirchia²

Prateek Harne³

¹ Internal Medicine, SUNY Upstate Medical University, Syracuse, New York, USA

² Pathology, SUNY Upstate Medical University, Syracuse, New York, USA

³ Internal Medicine, SUNY Upstate University Medical University, Syracuse, New York, USA

Address correspondence to:

Muhammad B Malik

750 E. Adams St., Syracuse, New York 13210,

USA

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Article ID: 101136Z01MM2020

doi: 10.5348/101136Z01MM2020CI

How to cite this article

Malik MB, Mirchia K, Harne P. Gastric leiomyosarcoma: A common tumor in an uncommon location. Int J Case Rep Images 2020;11:101136Z01MM2020.

ABSTRACT

No Abstract

Keywords: Gastric leiomyosarcoma, Gastroenterology, Oncology, Tumor

Case Report

A previously healthy 51-year-old female presented with gradually worsening, 10/10 non-radiating epigastric abdominal pain associated with nausea, bilious vomiting, and weight loss. Computed tomography (CT) of the abdomen with intravenous contrast showed a large 10.7 × 9.5 cm exophytic mass in the antrum/body of the stomach (Figure 1A). An upper endoscopic evaluation revealed a large fungating, infiltrative, and ulcerated mass in the gastric body (Figure 1B). Histopathology of the biopsied mass was notable for spindle cells with a fascicular pattern, moderate nuclear atypia, abundant eosinophilic cytoplasm, and numerous mitotic figures. Immunohistochemistry analysis revealed that the tumor was diffusely positive for smooth muscle actin (SMA) (Figure 2A), desmin (Figure 2B), and calponin (Figure 2C). Ki-67 stain (Figure 2D) showed a high labeling index of 60% indicating a high-grade leiomyosarcoma. There was a complete lack of reactivity with DOG-1 and CD-117 (c-KIT) which excluded the diagnosis of a gastrointestinal stromal tumor (GIST). No evidence of metastatic disease and no lymph node involvement were noted in the head, abdomen, or thorax on the respective CT scans which were done for staging. Due to the large size of the tumor, the patient was started on a neoadjuvant chemotherapy regimen consisting of doxorubicin, ifosfamide, and mesna to reduce tumor burden with a future plan for surgical excision.

Figure 1: (A) Computed tomography of the abdomen showing the exophytic mass in the antrum/body of the stomach. (B) Upper endoscopy showing large fungating, ulcerative mass in the gastric body.

Figure 2: (A) Immunohistochemistry stain diffusely positive for smooth muscle actin. (B) Immunohistochemistry stain diffusely positive for desmin. (C) Immunohistochemistry stain diffusely positive for calponin. (D) Immunohistochemistry stain diffusely positive for Ki-67 with a high labeling index.

Discussion

Leiomyosarcoma of the stomach is an extremely rare malignancy that accounts for fewer than 1% of gastric tumors [1]. Gastrointestinal stromal tumors were misdiagnosed as leiomyomas and leiomyosarcomas up until the early 2000s. An exophytic gastric tumor has broad differentials and diagnosis can be difficult to determine with radiology or histopathology alone [2]. Since the advent of KIT immunohistochemistry, primary gastric leiomyosarcoma can be distinguished from GIST due to the presence of CD117 (c-KIT) and DOG-1 in GIST cases and the presence of desmin, SMA, calponin in leiomyosarcomas [3].

Conclusion

Differentiation between GIST and leiomyosarcoma is of great clinical importance as the therapeutic approach is vastly different. Gastrointestinal stromal tumor usually responds to KIT-directed immunotherapy and is intrinsically resistant to many chemotherapeutic drugs.

REFERENCES

Sato T, Akahoshi K, Tomoeda N, et al. Leiomyosarcoma of the stomach treated by endoscopic submucosal dissection. Clin J Gastroenterol 2018;11(4):291–6. [CrossRef] [Pubmed] Back to citation no. 1

Hasnaoui A, Jouini R, Haddad D, et al. Gastric leiomyosarcoma and diagnostic pitfalls: A case report. BMC Surg 2018;18(1):62. [CrossRef] [Pubmed] Back to citation no. 1

Mehta V, Rajawat M, Rastogi S, Phulware RH, Mezencev R. Leiomyosarcoma of the stomach with metastasis to the liver: A case report with review of the literature. Future Sci OA 2017;4(2):FSO264. [CrossRef] [Pubmed] Back to citation no. 1

SUPPORTING INFORMATION

Acknowledgments

Harvir Singh Gambhir, MD, attending mentor.

Author Contributions

Muhammad B Malik - Substantial contributions to conception and design, Drafting the article, Revising it critically for important intellectual content, Final approval of the version to be published

Kanish Mirchia - Interpretation of data, Drafting the article, Final approval of the version to be published

Prateek Harne - Interpretation of data, Drafting the article, Final approval of the version to be published

Consent For Publication

Written informed consent was obtained from the patient for publication of this article.

Data Availability

All relevant data are within the paper and its Supporting Information files.

Competing Interests

I hereby certify that, to the best of my knowledge: (1) the work that is reported on in said manuscript has not received financial support from any pharmaceutical company or other commercial interest except as described below, and (2) neither I nor any first-degree relative has any special financial interest in the subject matter discussed in said manuscript. (I understand that an example of one type of such special financial interest would be ownership, by me or a first-degree relative, of a company that sells a product relating to the subject matter of the manuscript.)

Copyright

© 2020 Muhammad B Malik et al. This article is distributed under the terms of Creative Commons Attribution License which permits unrestricted use, distribution and reproduction in any medium provided the original author(s) and original publisher are properly credited. Please see the copyright policy on the journal website for more information.