Pathology of Intramuscular Lipoma

Dr Sampurna Roy MD                    2022

Age: Occurs in middle to late adult life.

Site: Presents as deep seated slow growing usually painless mass in the large muscles of the extremities specially those of the thigh, shoulder and upper arm and in the chest wall.

Other locations include the spermatic cord, the mediatinum or in the periosteal location.

Types: This benign tumour may be divided into infiltrative and well-circumscribed types.

Histopathology: Histologically striated muscle fibres are diffusely infiltrated by mature adipocytes.

No atypical features are present.

Blood vessels are scarce (capillary-sized) helps in distinguishing from intramuscular hemangioma.

Differential Diagnosis:  well differentiated liposarcoma ;  diffuse lipoblastomatosis  (occur in infants and children; subcutis and muscle are affected ; more than one type of muscle involved).

The infiltrative tumours are known to recur locally in 20% of cases if incompletely excised.

Intramuscular lipoma of the abductor digiti minimi mimicking intramuscular haemangioma.

Intramuscular lipomas: Large and deep benign lumps not to underestimated. review of a series of 51 cases.

Co-existence of intramuscular spindle cell lipoma with an intramuscular ordinary lipoma:report of a case.

Intramuscular lipoma of the tongue masquerading as angioedema.

An unusual location of ossified intramuscular lipoma: a case report.

Intramuscular lipoma of tongue.

Intramuscular myxoid lipoma in the proximal forearm presenting as an olecranon mass with superficial radial nerve palsy: a case report.

Intramuscular lipoma of the sternocleidomastoid muscle.

Unusual intramuscular lipoma of deltoid muscle.

Intramuscular infiltrating lipoma of the longus colli muscle. a very rare cause of neck structures compression.

HMGA2-NFIB fusion in a pediatric intramuscular lipoma: a novel case of NFIB alteration in a large deep-seated adipocytic tumor.

Giant intramuscular lipoma of the tongue: a case report and literature review.