Painful intramuscular lipoma of the thigh

Intramuscular Lipoma within a Free Myocutaneous Flap: Systematic Review and Management

Lipomas are a common finding often of little clinical significance, but they can pose a challenge to the microsurgeon if discovered during flap harvesting, especially if found within the muscle along the pedicle or perforators. Here the authors report a case in which a well-circumscribed intramuscular lipoma was discovered within the muscle of a free myocutaneous right anterolateral thigh (ALT) vastus lateralis free flap. To the authors' knowledge, the management of lipoma during flap harvesting has not been previously discussed in the literature. A systematic review was performed, and an approach for the management of myocutaneous flaps containing a lipoma was described. Underappreciated considerations including lipoma location, growth pattern, and proximity to pedicle and perforators must be taken into account when evaluating a lipoma during flap harvest.

Intramuscular lipoma: a review of the literature

Lipomas are the most common type of soft tissue mesenchymal tumors. They are typically located subcutaneously and consist of mature fatty tissue. When they occur under the enclosing fascia, they are called deep-seated lipomas. Infrequently, lipomas can arise inside the muscle and are called intramuscular lipomas. Intramuscular lipomas have been commonly investigated and categorized in the same group as other deep-seated and superficial lipomatous lesions. Their clinical, histological and imaging characteristics may resemble well-differentiated liposarcomas, further adding to the difficulties in the differential diagnosis. This article summarizes the available literature and describes the typical epidemiological, pathological and clinical features of intramuscular lipomas, as well as delineating their treatment and prognosis.

A large parosteal ossifying lipoma of lower limb encircling the femur

Introduction

Lipoma is a benign soft tissue neoplasm that may contain mesenchymal elements, as a result of metaplastic process. Ossification in benign and malignant soft tissue tumors can also manifest due to metaplastic process.

Case presentation

A 45 year old woman presented with a large thigh mass. The mass was developed one and a half year ago which insidiously increased in size and was associated with movement restriction. Radiological findings revealed soft tissue neoplasm on antero-medial aspect of thigh encircling the femur and displacing adjacent muscles. Fine trabeculations were seen in neoplasm suggestive of ossification. Excision of the mass was performed and histopathology revealed adipocytes with mature bony trabeculae possessing prominent osteoblastic rimming suggestive of ossifying lipoma.

Conclusion

It is important to recognize this variant of lipoma as it is associated with a better clinical outcome in contrast to most of the deep seated soft tissue neoplasms. Secondly it should also be differentiated from myositis ossificans and heterologous differentiation in other soft tissue neoplasms. We suggest an algorithmic approach to the diagnosis of ossifying soft tissue neoplasms histopathologically. Mature bony trabeculae with prominent osteoblastic rimming in a soft tissue lesion are due to a metaplastic process and should not be confused with osteosarcoma.

[An unusual location of juxtaosseous ossified lipoma. A case report]

We report a case of juxtaosseous ossified lipoma. Clinical and radiological features make it an exceptional case, because of its location at the hand and presence of cortical erosion of the subjacent bone. However, the histological study of this rare benign tumor showed neither cytonuclear atypia nor increasing number of mitosis. It made easy its surgical treatment, without any functional sequelae. The patient reported no local recurrence in the follow-up; the risk is low, given its histological character.

Intramuscular lipoma of the sternocleidomastoid muscle

Intramuscular lipoma is a rare benign mesenchymal tumor that infiltrates the skeletal muscle. These lipomas are usually found on the extremity, but rarely occur in the head and neck. To our knowledge, only 4 cases of intramuscular lipoma in the sternocleidomastoid muscle have been reported in the literature. The recurrence rate of intramuscular lipoma is high, and it shows the pattern of infiltration to tissues, and thus different from general lipomas, its resection should include adjacent normal muscular tissues. In addition, although rare, concerning intramuscular lipoma that developed in the head and neck area, because important structures are present densely in a small space, it is important to establish a preoperative plan by determining the size and location of the tumor through preoperative clinical and radiologic tests. We had a case of intramuscular lipoma in sternocleidomastoid muscle and resected the mass completely including a portion of attached muscles. The postoperative course was uneventful, and no evidence of recurrence occurred after 6 months of follow-up.

Ossifying lipoma of the thigh

Lipomas are common soft-tissue tumours that are usually found in the subcutaneous adipose tissue. Occasionally, they may contain mesenchymal elements other than adipose tissue, including osseous components. These ossifying lipomas are usually located near or within bone, and it is very rare for a lipoma with no connection to bone to contain mature osseous tissue. We describe a case of a symptomatic ossifying intramuscular lipoma of the thigh.

Lipoma due to chronic intermittent compression as an occupational disease

A total of 15 coppersmiths who do the job as a traditional profession in Kahramanmaras Province were retrospectively analyzed for revealing a possible relationship of lipoma formation and chronic compression, as the work characteristic related to mechanical pressure to the right thoracal and shoulder region. The workers were examined and their historical data were noted. Chronic compression sites in the patients were also evaluated by magnetic resonance imaging and ultrasonography. The ages were between 30 and 52 years. Body mass index ranged from 18.6 to 38.8. Five were operated for visible lipomatous masses at their injured sites. All of the specimens were reported as containing mature adipocytes. An increased subcutaneous fat thickness at the injured sides of the patients was seen when compared with the uninjured contralateral sides using ultrasonography. At the magnetic resonance images, no capsule intensity was observed in the lipomatose masses. Subcutaneous fat of injured right mammarial regions was thicker than the other contralateral sides in all of the cases. The most prominent lipomas were seen in obese workers, and strong evidence for chronic trauma and lipoma formation as an occupational disease was obtained from the study.