Myelolipoma mimicking osteosarcoma in the distal femur

Rib myelolipoma: a case report

BACKGROUND

Myelolipoma is an uncommon benign tumor composed of mature adipose tissue and hematopoietic elements. These tumors generally affect the adrenal glands, with anomalous presentations being rare and with few cases described in the literature. Most myelolipomas are asymptomatic and discovered incidentally, either through imaging tests or at autopsies. However, depending on the location and size of the lesion, myelolipomas can cause symptoms of mass effect. This article aims to report a very rare presentation of a symptomatic primary myelolipoma affecting the ribs.

CASE PRESENTATION

A 21-year-old white female patient presented with a complaint of burning chest pain over 3 months, with gradual worsening in intensity, accompanied by a progressively growing bulge in the right thoracic wall. The patient underwent thoracotomy of the fifth and sixth ribs with complete excision of the lesion with a safety margin. Thoracic wall reconstruction was performed using a polypropylene mesh. The patient had a good postoperative course and was discharged on postoperative day 3. Histopathological examination revealed a histological image consistent with myelolipoma.

CONCLUSIONS

This report underscores the importance of considering a myelolipoma diagnosis for tumor masses in the ribs.

Malicious Tumor? Pathological Fracture of the Femur in Children Caused by Myelolipoma: A Case Report and Review of Literatures

Myelolipoma is a kind of benign lipoma containing myeloid cells. It is a rare type of tumor that typically presents as an occasional adrenal tumor, generally manifesting as a nonfunctional adrenal mass. Although it can occur in extra-adrenal tissues, its occurrence in bone tissue is extremely rare. Most cases are discovered accidentally during physical examinations of adults, and there are currently no reports of cases with pathological fractures as the main symptoms. We present a case of a 15-year-old teenager who developed a pathological fracture caused by femoral myelolipoma. The diagnosis of the specific type of bone tumor of the patient was determined through pathology and imaging. To treat the condition, we utilized a technique known as the "soft drill" to fully access the tumor space, remove the bone septum, and scrape away the diseased tissue. The fracture was then stabilized using a hybrid external fixation. After a 2-year follow-up period, there was no recurrence of the bone tumor. This case is the first case of intraosseous myelolipoma that occurred in a minor with the initial symptom of pathological fracture, filling the gap in our existing body of knowledge and providing a reference for the treatment of this type of intraosseous myelolipoma.

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.

Intramedullary/intraosseous myelolipoma in a patient with pathologic fracture

Background

Intramedullary lipomatous tumors are rare and mostly reported in the metaphysis of the femur, tibia, and fibula. Myelolipomas are very rare tumors composed of adipose tissue and hematopoietic cells commonly reported in adrenal gland. We report the first reported case of intraosseous myelolipoma with a pathologic fracture in a young woman.

Case presentation

Patient is a young woman who carried a diagnosis of systemic lupus erythematosus, antiphospholipid syndrome, and hyperparathyroidism. Radiologic studies were done after the patient reported right lower leg pain lasting for a month. Radiologic examination showed a large osteolytic lesions with pathologic fracture affecting the medial aspect of the proximal tibia with extensive soft tissue calcification. The initial clinical and radiographic suspicion was brown tumor secondary to the hyperparathyroidism. Curettage of the lesion yielded large fragments of mature adipose tissue punctuated by a variable amount of mature hematopoietic cells. The histopathologic features were suggestive of myelolipoma. The overall radiographic and histopathologic features supported a diagnosis of myelolipoma. The diagnosis of intraosseous myelolipoma can be challenging in small samples such as core biopsies.

Conclusions

The differential diagnoses of intraosseous myelolipoma include normal bone marrow, intramedullary hematopoiesis, and other benign lesions. The gold standard diagnosis is histopathologic examination. However, clinical and radiographic features have important roles in the diagnosis of this rare lesion. Due to the rarity of this tumor and lack of formal guidelines for management, the case-to-case basis treatment is recommended.