Successful removal of a giant intrathoracic lipoma: a case report and review of the literature

Abstract

We report a case of a 44-year old female who presented to her physician complaining of mild dyspnea. A follow-up chest X-ray and chest computed tomography scan revealed a giant bilateral intrathoracic mass, filling the right thoracic cavity and extending across the anterior mediastinum into the left chest cavity. This large mass caused a marked shift in the midline structures, displacing the heart to the left hemi-thorax. The patient underwent surgical removal of the thoracic and breast mass, with histologic examination confirming the diagnosis of a giant intrathoracic lipoma, weighing 4,320 grams and measured 34 × 28 × 11 cm. It is the largest intrathoracic lipoma documented in the modern literature. Case presentationA 44-year old African American female who worked as a phlebotomist presented to her primary care physician complaining of mild shortness of breath and a 4-pillow orthopnea for many years (>10 years). She was a nonsmoker, and maintained a healthy weight of 142 pounds for her 68" height. Her past medical history was significant only for uterine fibroids, for which she had undergone a myomectomy. She had conceived six healthy children, and the remainder of her family had no health problems. A subsequent chest x-ray and CT scan revealed a large mediastinal mass which occupied the majority of the right thoracic cavity and further extended across the anterior mediastinum into the left thoracic cavity ( figure 1A). The posteroinferior portion of the mass revealed several areas of dystrophic ring-type calcifications within a field of scattered dense soft tissue elements. These were thought to possibly represent a pleural-based liposarcoma, lipoma, teratoma, teratocarcinoma, or invasive thymoma of the anterior mediastinum. The mass shifted the heart and mediastinal vascular structures to the left of midline.In order to remove this large intrathoracic mass, the patient was explored through a transverse sternothoracotomy (clam-shell incision) to allow complete access to both pleural spaces and the mediastinum. Upon exposure of the anterior mediastinum, a large mass was visualized crossing this area and extending into both thoracic cavities ( figure 1B). The mass further extended into the left thoracic cavity and displaced the lower lobe of the left lung. The gross appearance was that of a thinly encapsu-

Mediastinal Liposarcoma

“…Therefore, although lipoma is histologically diagnosed as a benign tumor and grows slowly, those growing and causing clinical symptoms should be considered clinically malignant and subjected to surgical procedures for complete removal. Lipomas that increase in size may undergo transformation to liposarcomas although they rarely metastasize 4 …”

Pleural Lipoma

“…Lipo sarcomas have attenuation coefficients of higher than -50 Hounsfield units [7]. Histologically, pleural and intrathoracic lipomas contain abundant mature adipose tissue with no mitotic activity, with normal fibro-connective tissue in between but sometimes may contain foci of calcification and fat necrosis especially in large tumors [8]. Lipo sarcomas, on the other hand, have adipose Cells of varying size with hyperchromatic nuclei and eosinophilic cytoplasm.…”

“…Lipo sarcomas, on the other hand, have adipose Cells of varying size with hyperchromatic nuclei and eosinophilic cytoplasm. Liposarcomas can also have mitoses associated with multinucleated histiocytes and fatty necrosis seen in 25% of cases [8,9]. SFTP is a rare, usually benign and indolent growing tumor that accounts for approximately 5% of all pleural neoplasms [10].…”

Giant Intrathoracic Pleural Lipoma

“…The density is often not uniform because lipoma frequently contain fibrous stroma. Ramona et al [13] reported a case in which CT revealed several areas of dystrophic ring type calcifications within a field of scattered dense soft tissue elements.…”