Multifocal thoracic myelolipoma

Background:

A 63-year-old man with a smoking history of 30 pack-years was treated in Department of Gastroenterology because of recurrent abdominal pain. He had no history of weight loss, night sweats or fatigue. Apart from severe obesity a Barretts oesophagus, a gastritis and a diverticulosis were diagnosed. As an incidental finding in the abdominal computed tomography a paravertebral mass with a dimension of 48 × 48 × 25 mm was seen beside thoracic vertebrae at the level of T10 and the patient was referred to our Department of Thoracic Surgery for further evaluation.

Material and method:

On MRI scan an additional, second paravertebral tumor was shown at the level of T8 with a dimension of 10 × 17 × 15 mm. The encapsulated, heterogeneous tumors showed areas with high-signal intensity at T1-weighted imaging and T2-weighted imaging, combined with parts of low-to-intermediate signal intensity on T1WI and moderate signal on T2WI, corresponding to fatty and myeloid elements. An ¹⁸flourodeoxyglycose PET/CT was performed, where the masses presented without standard uptake value suggestive for malignancy. Following the imaging, a CT-guided biopsy of the larger mass was done for pathological examination.

Result:

The analysis of the specimen showed mature adipose tissue admixed with hematopoietic elements and led to the diagnosis of thoracic myelolipoma.

Conclusion:

Myelolipoma is a rare benign tumor and usually it is a lesion of the adrenal gland. Thoracic location is extremely uncommon and relevant differential diagnosis for paravertebral masses are neurogenic tumors, like schwannomas and ganglioneuromas.

Usually, thoracic myelolipoma is asymptomatic and only a minority show an increase in size at all. In these tumors median growth per year is reported to be 0.16 cm/year. While most significant complication in large adrenal myelolipoma is acute haemorrhage, to our knowledge, this complication was not reported for thoracic myelolipoma so far in international literature.

In consequence, in contrast to standard recommendations, we alternatively advocate active surveillance of rare thoracic myelolipomas.

We decided for conservative management in this case and the patient is monitored by yearly MRI scan. There was no growth of the myelolipomas within two years.