Purpose The aim of this study was to investigate the distribution of intramuscular giant lipomas in the functional compartments of the forearm and to compare their clinical, radiological and histopathological features with those reported in the current literature.
Methods The study included 12 patients who were surgically treated for intramuscular lipomas > 5 cm in size located in the forearm that had been confirmed histopathologically between April 2006 and March 2017. Data about the patients with respect to age, sex, affected side, localisation of the lipomas in the forearm functional compartments, size, histopathological features and recurrence were collected. According to the clinical complaints, direct radiography and magnetic resonance imaging were applied.
Results The average diameter was 6.5 cm (range: 5.5–9 cm). All lipomas had a well-defined border. All the patients presented with soft-tissue masses that were painless in seven patients. Five patients had nerve compression symptoms. When the lipomas were classified according to the functional compartments of the forearm, six of them were located in the superficial volar compartment, two in the deep volar compartment, two in the deep dorsal compartment and two in the lateral compartment. All lipomas were surgically removed by marginal excision. None had complications or recurrence at a mean of 6.5 years follow-up (range: 1–12 years) after surgery.
Conclusions Intramuscular lipoma is a relatively uncommon tumour, especially in the forearm. Because of the proximity to the neurovascular structures in the forearm, excision of lipomas should be performed with care and include wide incisions. Additionally, knowing the anatomical features of the compartment where the lipoma is localised in the forearm is important in planning surgery to enable easier dissection of the lipoma and lessen the risk of damage to adjacent neurovascular structures.
Level of evidence Level 4