A bilateral neoplasm in chest: a case report and literature review

Abstract

BackgroundMyelolipoma is a rare neoplasm composed of yellowish adipose tissue and reddish-brown tissue corresponding to hematopoietic or hemorrhages. It typically occurs in adrenal glands as a solitary, well-circumscribed mass, and the thoracic location is extremely unusual.Case presentationWe present a rare case who is a 54 years old male with bilateral Myelolipoma of the posterior mediastinum. He underwent the surgery via video-assisted thoracic surgery both sides interval 3 months. Histological examination showed both tumors consisted of mature fat tissue and hematopoietic tissue, including myeloid, erythroid, and megakaryocytic elements surrounded. We discussed the etiology, histopathology, differential diagnosis and recommended management of extra-adrenal myelolipoma and analyzed the features of the thoracic myelolipoma including mediastinal and pulmonary location.ConclusionsLiterature review showed 16 similar cases, with a 2/1 male/female ratio and a mean age of 58 years. Eight of sixteen cases were observed in the mediastinum and six of sixteen cases were displayed in the pulmonary and one showed on the chest wall. CT and MRI scans are able to indicate the presence of extra-adrenal myelolipoma. Pathological analysis is an effective method to clarify the diagnosis. Observation and surgery are two regular treatment methods. Small, asymptomatic tumors should be monitored, while large tumors that cause unendurable symptoms may be removed by surgery.

Myelolipoma of the posterior mediastinum in a patient with chronic dyserythropoietic anemia

“…The hematopoietic component was recognized by the presence of erythroid, granulocytic, and megakaryocytic series. In our patient, there were no bone spurs or hyperplasia of any hematopoietic component, and the adipose component did not present atypia 2 , 4…”

“…The extra-adrenal location is unusual (15%) and includes the retroperitoneum, pelvis, pre-sacral region, stomach, and liver. In the lungs and mediastinum, the occurrence of ML is quite infrequent accounting for 3% of all cases 1 , 2. This report shows an rare case of ML located in the posterior mediastinum in a patient with congenital dyserythropoiesis.…”

“…The mean age of these 28 patients with mediastinal MLs was 64 years, with a slight male predominance. The series reported by Shen et al2, which comprised 16 patients with thoracic ML, showed singular chest lesions in 13 cases 2. Patients with extra-adrenal MLs were older than those with adrenal lesions 6…”

“…In this setting, the gold standard examination for the diagnosis of ML is the histological examination 1 , 4. Macroscopically, generally, the ML are well-defined tumors that are often enclosed by a thin capsule measuring approximately 4-5 cm in diameter 2. The cut surface can be variegated, depending on the ratio between fat and hematopoietic tissues.…”

“…Shen et al2 and Xiong et al3 compiled some possible explanations for the genesis of ML: (i) it could be derived from bone marrow emboli that may lodge in different regions of the organism; (ii) it could be derived from embryonic primitive mesenchymal cells; (iii) it could be derived from the metaplastic transformation of embryonic stromal cells after chromosomal translocation, similar to that observed in myelogenous leukemia; and iv) some disorders, such as the endocrine diseases like Cushing's syndrome, diabetes mellitus, Addison's disease, Cohn's syndrome, pheochromocytoma, obesity, and even hypertension that accompany ML may play a role in the genesis of this neoplasm 2 , 3 , . Fonda et al7 proposed that ML may derived from projection of hematopoietic tissue (including stem cells) by bone microfractures.…”