First published case report in Case Reports


Introduction: Intermuscular lipomas constitute a small percentage of adipocytic neoplasms unlike the subcutaneous lipomas which are fairly common. The recurrence rate of intermuscular lipomas is 1%.

Case Report: A 58-year old man presented to the breast surgery clinic with a progressively increasing right breast prominence. About 7 years ago he had undergone excision of a right breast mass, which turned out to be an interpectoral lipoma. His MRI was done, and it showed a lipomatous mass confined to the right interpectoral region suggestive of recurrence of the lipoma. An ultrasound guided core biopsy excluded sarcoma. The mass was completely excised surgically. Final pathology confirmed a recurrent interpectoral lipoma.

Conclusion: Cases of interpectoral lipomas have been reported in the literature. However, to the best of our knowledge, this is the first case report of a giant recurrent lipoma between the pectoralis major and minor muscles. Caution is required in order to rule out liposarcoma in recurrent cases prior to re-excision.

Recurrent; Interpectoral; Intermuscular; Lipoma

Lipomas are the most common type of benign soft tissue mesenchymal tumours which mostly occur subcutaneously [1]. Sometimes they may arise in a deep location such as within a muscle or in between two muscles, termed as intramuscular and intermuscular lipomas respectively [1-3]. These deep-seated types draw attention because of their location and their tendency to recur, which may mimic a liposarcoma [1]. Intramuscular lipomas comprise 1.8% of adipocytic tumours, and intermuscular lipomas are even less common constituting only 0.3% of all adipocytic tumours [2]. The recurrence rate of intermuscular lipomas is 1% [3].

Intermuscular lipomas of the chest wall have been rarely reported in the literature and to the best of our knowledge there has been no reported case of a recurrent lipoma between the pectoralis major and minor muscles. We report the case of a recurrent giant chest wall lipoma in the interpectoral region.

A 58-year old, otherwise healthy man presented to the breast surgery clinic with an eight month history of progressively increasing right breast prominence and anterior protrusion. In 2008 he had similar complaints and was found to have an interpectoral lipomatous mass in the same location. It was excised at an outside institution and pathology confirmed it to be a lipoma.

Examination in our clinic revealed an enlarged right breast with the nipple more anterior in profile due to anterior displacement of the entire right breast. No lump was palpable on the chest wall or within the breast. His MRI showed a large 18.9 × 10.1 × 4.0 cm lipomatous mass interposed between the right pectoralis major and minor muscles, extending laterally towards the axilla and causing significant anterior displacement of the pectoralis major muscle. There was no extension across the midline to the left side or any intrathoracic extension Radiologically these findings were similar to the previous MRI findings of 2008 and thought to be likely due to a lipoma. However, due to the recurrent nature of the mass, liposarcoma needed to be excluded. Ultrasound guided core needle biopsy of this mass was performed with a 14 G biopsy needle, and it was confirmed to be a fibroadipose tissue fragment consistent with a lipomatous tumour. The provisional diagnosis of recurrent giant chest wall lipoma was made, and a complete excision under general anesthesia was planned.

Veronica Thompson
Riya Parker
Associate Editor
International Journal of Case Reports