Giant Intramuscular Lipoma Otot Biceps Brachii

Abstract

Intramuscular lipoma is a relatively uncommon condition and accounts for just 1,8% of all primary tumors of adipose tissue and less than 1% of all lipoma. This tumor arises within skeletal muscle fibers at various locations. However, giant intramuscular lipomas of biceps brachii muscle are rare tumors.
 A 48-years old man presented with a mass on his right upper-arm. The mass existed for one year and has since increased in size. On physical examination, the mass was pain upon palpation and completely mobile. Plain radiography, the soft tissue mass unremarkable. Computed tomography (CT) scan revealed a hypodense mass situated within right biceps brachii muscle with -72 until -83 Hounsfield. Magnetic resonance imaging (MRI), the mass was found inside of biceps brachii muscle. In T1- and T2- weighted images, the lesion area demonstrated high signal intensity, and SPAIR showed signal suppression similar to normal fat. The patient underwent radical excision of the lesion, which was found to be greater than 12 cm in size. Final pathology revealed intramuscular lipoma.
 A lipoma of greater than 5 cm is classified as a giant lipoma. Giant lipoma in the upper extremities and involving biceps brachii muscle are rare. The plain radiographs may either be unremarkable or may demonstrate a radiolucent soft tissue mass of fat opacity. On CT and MRI, the lipoma appears as an non-invasive mass with homogenous fat signal intensity. The main differential diagnosis of intramuscular lipomas is well-differentiated liposarcomas. The proper management is open excision. The pathological report is vital to confirm the diagnosis.
 We reported a rare case of giant intramuscular lipoma of biceps brachii who was successfully opened excision at our institute. CT scan and MRI can identify and localize these tumours, and facilitate the operative planning