Al Abdulsalam A, Al Safi S, Aldaoud S, Al-Shadidi N, Dhar P. Intramuscular myxoma of the left thigh: A case report.
Int J Surg Case Rep 2022;
100:107710. [PMID:
36252547 PMCID:
PMC9574699 DOI:
10.1016/j.ijscr.2022.107710]
[Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 09/25/2022] [Accepted: 09/25/2022] [Indexed: 11/25/2022] Open
Abstract
Introduction and clinical importance
Intramuscular myxoma (IM) is a rare benign soft tissue tumor that involves the musculoskeletal system with a reported incidence of 0.1–0.13 per 100,000. The mean age of diagnosis is 40–70 years of age, with female predilection. The most common site of involvement is the thigh, however, it may present in other areas such as the upper arm, calf, and buttock.
Case presentation
A case of a 45-year-old female without a significant past medical or surgical history who presented with 3-year history of a slow-growing, painless mass in her left upper thigh. MRI scan was performed which showed intramuscular soft tissue mass lesion 9 × 6 × 4.5 cm implicating the left distal vastus medialis muscle. A fine needle aspiration was inconclusive so a core needle biopsy was performed which was suggestive of intramuscular myxoma. A complete surgical excision of the mass was done and the postoperative period was uneventful and patient was discharged home. The final histopathological examination confirmed the diagnosis of intramuscular myxoma.
Discussion
Intramuscular myxoma is a rare benign soft tissue neoplasm. 50 % of cases commonly occur in the thigh. IM has an unknown etiology, however, the literature has showed common gene mutations such as the GNAS gene mutations (Guanine nucleotide binding protein, alpha stimulating). Imaging modalities such as ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) are useful in diagnosis of soft tissue mass but not specific to intramuscular myxoma. Histopathological examination is the gold standard for diagnosis. The treatment of choice is surgical excision with clear margins to prevent recurrence, which is extremely rare.
Conclusion
Intramuscular myxomas, although benign and rare, should be in the differential diagnosis of soft tissue lesions due to the similarity they share with malignant tumors such as sarcomas. Histopathological examination is the gold standard for diagnosing a soft tissue lesion and surgical excision is the treatment of choice.
Soft tissue masses are common but intramuscular myxoma is a rare differential diagnosis
Clinical examination and imaging modalities are inconclusive in formulating the diagnosis of intramuscular myxoma
Histopathological examination is the gold standard for diagnosing cases of intramuscular myxoma
Surgical excision with a gross negative margin is the treatment of choice
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