Pseudosarcoma of the thigh: a rare case of massive localized lymphedema

Massive localized lymphedema, also called pseudosarcoma, is a rare condition associated with morbid obesity. Accurate identification of this entity helps the physician make the distinction between this condition and other soft tissue tumors, especially with the increasing rate of obesity worldwide. Obesity and increased caloric intake lead to storage of the excess energy in the form of adipose tissue. The excess adipose tissue disturbs the lymphatic vessels, leading to massive edema localized mostly in the lower extremity, reaching a substantial size and weight that interferes with the quality of life of the individual in question. The mass can cause cosmetic but more importantly functional and structural defects, leading to altered biomechanics with increased risk of deep vein thromboembolism. Below is a presentation of a patient presenting with complaint of a massive medial thigh mass. After much investigation, consultation, and use of diagnostic radiologic modalities it was diagnosed as what is referred to in the literature as massive localized lymphedema, or pseudosarcoma. This mass was managed by surgical excision and the diagnosis was further confirmed by pathologic analysis. After the excision, our patient regained his ability to ambulate on his own, with the help of a rehabilitation program and physical therapy. Massive localized lymphedema needs to be on the differential diagnosis of any morbidly obese patient presenting with mass, especially in the lower extremities. Adequate knowledge about this condition enables the physician to make the distinction between pseudosarcoma and true soft tissue sarcomas.