Parosteal lipoma of the forearm

Abstract

Rationale: Parosteal lipomas are rare neoplasms comprising mature adipocytes situated in a proximity to bone. Although these tumors follow a benign course, the reactive osseous changes that may occur with such lesions might raise the suspicion of malignancy.Patient Concerns: Here we present a case of a 33-year-old male patient complaining of pain and swelling in the right anterior forearm without history of trauma.Diagnosis: An magnetic resonance imaging of the region revealed a lobulated intramuscular fat intensity mass within the supinator muscle. Bony projection inseparable from the anterolateral radial diaphyseal cortex and periosteum was also seen. The radiological features suggested the diagnosis of parosteal lipoma.Intervention: After the radiological diagnosis of a parosteal lipoma, the patient was offered a total surgical excision of the mass.Outcomes: The mass was removed successfully. Histopathology showed mature benign adipose tissue bordered by thin fibrous septa confirming the diagnosis of parosteal lipoma. Follow-up magnetic resonance imaging after 6 months did not reveal any signs of complications or recurrence.Lessons: Distinction of the features of parosteal lipomas is needed to establish the accurate diagnosis, discriminate it from malignant lesions, predict potential neurovascular compromises, and follow up until a curative action is planned.

Parosteal lipoma of the left femur: A case report

“…They account for 0.3% of all lipomas, occur mostly in middle aged patients, and are equally frequent in males and females. 1,2 These neoplasms often present in the diaphysis of long bones, most commonly in the femur, radius, tibia, and humerus. 1,2 Most patients present with an asymptomatic slowly growing palpable mass.…”

“…1,2 These neoplasms often present in the diaphysis of long bones, most commonly in the femur, radius, tibia, and humerus. 1,2 Most patients present with an asymptomatic slowly growing palpable mass. Vascular and neurological disturbances may be reported if adjacent structures are compromised.…”

“…Parosteal lipomas are rare benign fat‐containing tumors that are closely related to the periosteum. They account for 0.3% of all lipomas, occur mostly in middle aged patients, and are equally frequent in males and females 1,2 . These neoplasms often present in the diaphysis of long bones, most commonly in the femur, radius, tibia, and humerus 1,2 …”

“…Parosteal lipomas are rare and unique benign neoplasms composed of mature adipose tissue in close proximity to the periosteum 1,2 . They account for 0.3% of all lipomas, can affect either sex, and occur more frequently in middle‐aged patients (40–60 years old) 2 .…”

“…Most patients tend to be asymptomatic or may only complain of recent swelling or growing mass. Despite their rarity, the prognosis tends to be very favorable—there have been no proven reports of malignant transformation and only one report of a local recurrence in the most recent literature 2,3 …”