Review of primary extra-adrenal myelolipoma of the thorax

Surgical Management and Outcome of Extra-adrenal Myelolipomas at Unusual Locations: A Report of 11 Cases in a Single Center

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The first case series with eleven consecutive patients diagnosed with EAMs in the spinal or intraosseous regions.

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EAMs involving the thoracic vertebral body or the humerus have not previously been reported in the English literature.

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The surgical outcome and prognosis of EAMs are excellent and surgery can serve as the method of radical treatment.

Purpose

Extra-adrenal myelolipomas (EAMs) are rare benign tumors composed of both mature adipose and hematopoietic tissues with unclear etiology. There have been only sporadic case reports about the clinical characteristics and management of EAMs. Here we present our experience and practice in the clinical diagnosis and treatment of 11 consecutive patients with EAMs.

Method

We retrospectively reviewed 11 consecutive patients, who received surgeries in our department and were confirmed as having EAMs by postoperative histopathology from April 2016 to December 2021. Clinical information and follow-up data of all patients were collected and analyzed afterwards.

Results

Of the 11 EAM patients (7 male and 4 female) with a mean age of 47.6 years, 3 were asymptomatic and 8 were symptomatic with a mean symptom duration of 6.07 months. EAMs were found in the thoracic spine in 4 cases, paravertebral mediastinal regions in 3 cases, ilium in 2 cases, humerus in 1 case, and rib in 1 case. All patients were initially misdiagnosed as other tumors by radiologists. All 11 patients received gross total excision or curettage with a mean intraoperative blood loss of 781.82 ± 1143.3 ml and a mean operation duration of 180.91 ± 98.41 min. Patients’ Frankel scores and Karnofsky Performance Status score were improved or at least preserved postoperatively. No significant complications occurred postoperatively. All the 11 patients survived, and no local recurrence or distant metastasis occurred during the mean follow-up period of 42.0 months.

Conclusion

The surgical outcome and prognosis of EAMs are excellent and surgery can serve as the method of radical treatment.

An unusual diagnosis of paravertebral lesions: mediastinal myelolipoma

Background

Mediastinal myelolipoma is extremely rare. It is a benign nonfunctioning tumor composed of hematopoietic tissue and mature fatty tissue. Although computed tomography and magnetic resonance imaging are effective in diagnosing mediastinal myelolipoma, a definitive diagnosis is difficult to establish for rare extra-adrenal myelolipomas by imaging alone. Such tumors are often misdiagnosed as malignant retropleural liposarcoma, denoting a poor prognosis.

Case presentation: We herein describe a 72-year-old man with multiple bilateral paravertebral mediastinal myelolipomas and discuss the imaging findings and differential diagnoses. We used a computed tomography-guided core biopsy to attain a preoperative diagnosis. Using this technique, we avoided an unnecessary surgical procedure for the patient’s asymptomatic and relatively small lesions.

Conclusions

Instead of biopsy by lesion excision, we advocate conducting a precisely targeted, minimally invasive computed tomography-guided core biopsy to obtain a definitive preoperative diagnosis and thus avoid unnecessary surgery for mediastinal myelolipoma, a benign nonfunctioning tumor.