Unusual presentation of metastatic leiomyosarcoma-right forearm swelling

Abstract

Leiomyosarcoma (LMS) is a rare smooth muscle connective tissue tumour accounting for around 11% of soft-tissue sarcomas (Ducimetiere F, Lurkin A, Ranchere-Vince D, Decouvelaere AV, Péoc'h M, Istier L et al. Incidence of sarcoma histotypes and molecular subtypes in a prospective epidemiological study with central pathology review and molecular testing. PLoS One 2011;6:e20294). LMS are highly unpredictable tumours that can present at any site in the body, most commonly in the uterus, stomach, small intestine and retroperitoneum. There are few published case reports within the literature on the metastatic spread of LMS to skeletal muscle. We present an unusual presentation of metastatic Leiomyosarcoma in the right forearm of a 71-year-old male treated with limb-sparing surgical excision. This case report demonstrates the unusual and unpredictable nature of metastatic LMS presentation, which poses difficulty in diagnosis and management.

Figure 1:

Pre-treatment contrast MRI of forearm showing large soft-tissue mas lesion involving the flexor aspect of right forearm (a) axial T2, (b) coronal T2, (c) axial T1 and (d) coronal T1.

Figure 2:

Post-treatment contrast MRI of the forearm showing curative resection and no evidence of recurrence in the flexor compartment (a) sagittal T1, (b) sagittal T2 and (c) coronal T1.