Age / Sex : 41 / M

Chief complaint :

5-6 months ago, incidentally found palpable lump in the calf

Courtesy :  전지영 (Ji Young, Jeon)/ 가천대길병원 (Gachon University Gil Medical Center)

Leiomyoma in soleus muscle

Discussion

Findings:

Well-defined oval lesion in soleus muscle which is isointense on T1W with split fat sign, hyperintense on PD and fat-suppressed T2W images. Post-contrast coronal and axial images show avid heterogeneous enhancement.

 
Differential Diagnosis:

 Intramuscular peripheral nerve sheath tumor

 Hemangioma

Intramuscular angioleiomyoma

Discussion:

 Leiomyoma is a benign, usually solitary tumour of smooth muscle origin commonly involving the organs of the body composed of smooth muscle such as the uterus, urogenital tract and gastrointestinal tract. When found in soft tissue, it usually involves the dermis and subcutaneous layer. It very rarely affects the deep soft tissue. The deep leiomyomas have been found most frequently within skeletal muscle originating from vessels with unstriated muscle. They are more common in adults and rarely described in children. 

References:

McCarthy AJ, Chetty R. Benign Smooth Muscle Tumors (Leiomyomas) of Deep Somatic Soft Tissue. Sarcoma. 2018 Sep 9;2018:2071394. doi: 10.1155/2018/2071394. PMID: 30271265; PMCID: PMC6151232.

Fitzhugh VA, Wenokor C, Beebe KS, Aisner SC. Leiomyoma of deep soft tissue mimicking calcific myonecrosis. Radiol Case Rep. 2016 Sep 17;11(4):430-433. doi: 10.1016/j.radcr.2016.08.003. PMID: 27920874; PMCID: PMC5128368.

Sengul I, Sengul D. Deep Soft Tissue Leiomyoma of the Lower Extremities: a Case Report. Acta Chir Belg. 2009 Jan;109(1):104-105. doi: 10.1080/00015458.2009.11680386. PMID: 27416298.