Large Parosteal Lipoma without Periosteal Changes

Abstract

Summary:Parosteal lipoma is a rare tumor, accounting for approximately 0.3% of all lipomas. Bony lesions are often found in patients with this tumor (59.2%), making the differential diagnosis of malignant tumors important. Our case was a 64-year-old male patient who complained of a 25 × 15-cm mass on his right thigh that had grown rapidly over a 2-month period. On magnetic resonance imaging, a high-intensity lesion was observed on the surface of the femur beneath the vastus medialis muscle on T1 and T2 images, with low intensity on a T1 fat suppression image. No significant bony changes were detected. During total tumor resection, the tumor was found on the femur with tight continuity, with tiny areas of spiculation palpable on the bone surface. The exact tumor size was 18 × 13 × 6 cm. The pathological diagnosis was lipoma, the same result as in the former open biopsy. This case was the largest parosteal lipoma of the femur reported without periosteal changes. In cases of deep parosteal lipomas, the detection of rapidly progressive and growing pseudotumors with ossification or chondromatous changes implies malignancy. A preoperative biopsy is mandatory and must be followed by careful planning and preparation for handling in malignant cases. Plastic surgeons should therefore keep the diagnosis of parosteal lipoma in mind to provide appropriate (not too much or too little) surgical treatment.

Parosteal lipoma of proximal radius: A rare case report and its clinical approach

“…3 Unlike other lipomas, parosteal lipomas present late and are relatively difficult to diagnose because of its deep-seated nature. They are usually small lesions and one of the largest parosteal lipoma reported is by Aoki et al 8 in femur in 2014. These lesions are usually asymptomatic unless complicated by compression over nearby neurovascular structure leading to neuropraxia or vessel engorgement, or restricted motion of adjacent joint.…”

Parosteal lipoma of the radius with posterior interosseous nerve palsy

“…Parosteal lipomas are rare, accounting for only 0.3% of all lipomas. They are usually located in the proximal radius, humerus, femur and tibia 8–12. Yet, even more, unusual cases of parosteal lipomas of the clavicle, ribs, scapula, spine and even mandible were reported 13–16…”

Parosteal osseous lipoma of the temporal bone concurrent with involvement of the parotid salivary gland

“…Паростеальная липома составляет 15% всех костных липом, 0,3% от общего количества липом и менее 0,1% всех опухолей костной ткани [2,4]. Средний возраст больных 41-50 лет, чаще встречается у мужчин, наиболее частая локализация -диафиз бедренной, большеберцовой и лучевой кости.…”

“…Изменения периоста наблюдаются в 2 / 3 случаев паростеальных липом [4]. Помимо формирования экзостозов описаны также изгибы, волнообразные изменения и эрозии надкостницы [1,2].…”