Retroperitoneal Extraadrenal Myelolipoma: Technetium-99m Sulfur Colloid Scintigraphy and CT Imaging

Stealthy Encroachment: Unraveling an Encounter With Renal Myelolipoma

Myelolipoma of the kidney is an exceedingly unusual benign tumor of hematological components mixed with mature adipose tissue. We present a case of a 59-year-old male who presented with left flank pain and was found to have an atrophic left kidney on imaging studies. A computed tomography (CT) scan revealed a small and shrunken left kidney with an extrarenal pelvis. A diethylenetriamine pentaacetate (DTPA) scan results showed a total glomerular filtration rate (GFR) of 45.6 ml/min with a non-functional left kidney. The patient underwent a left nephrectomy, and a histopathological examination confirmed the diagnosis and highlighted the distinctive morphological features of this rare entity. Postoperatively, the patient experienced a complete resolution of symptoms. This case underscores the importance of considering myelolipoma in the differential diagnosis of renal masses and highlights the successful management of symptomatic cases through surgical intervention. Awareness of this rare tumor is crucial for accurate diagnosis and appropriate management. Further studies are needed to elucidate the natural history and optimal treatment strategies for renal myelolipomas.

Myelolipoma of Kidney: A Rare Extra-Adrenal Tumor in an Unusual Site

Myelolipoma of the kidney is a very rare benign disease which is composed of mature adipose tissue admixed with mature hematopoietic elements in varying proportions. The most common location of myelolipoma is in the adrenal glands, but extra-adrenal myelolipomas in other locations such as the retroperitoneum, presacral region, pelvis, and mediastinum has also been reported. In this case report, we present a case of huge extra-adrenal myelolipoma in renal parenchyma which is rare site for its origin. We report a case of extra-adrenal myelolipoma occurring in the left kidney of a 46-year-old Indian man. We describe the radiological and clinicopathologic features of this unusual tumor with a review of the literature. This case is noteworthy because the tumor was very enlarged and its site was unusual. It is generally impossible to distinguish extra-adrenal myelolipoma from other retroperitoneal tumors by radiological imaging given the rarity of tumor more cases need to be reported to elucidate its biological behavior.

Presacral Myelolipoma: The Usefulness of a 99mTc-Albumin Nanocolloid Scintigraphy

Myelolipoma is a rare mesenchymal tumor consisting of adipose tissue and hematopoietic cells. Found usually in the adrenal region, however, few cases have been reported in extra-adrenal regions, most frequently in the presacral region. It is important to recognize such tumor, as it can attain massive size and causes pressure symptoms, and needs to be differentiated from malignant tumors, including liposarcomas. Although CT and MRI can suggest a diagnosis of myelolipoma, these are not conclusive. The hematopoietic cells are enhanced by a Tc-albumin nanocolloid scintigraphy and help to distinguish myolipoma from other entities.

Retroperitoneal extra-adrenal myelolipoma misdiagnosed as liposarcoma: A case report

Myelolipomas are rare benign tumors that contain a mix of fatty and hematopoietic tissues. These tumors are frequently seen in the adrenal glands. While extra-adrenal myelolipomas are extremely rare, once identified, they are commonly found in the retroperitoneum––particularly the presacral region. Because of the fat content, these tumors can be easily mistaken for retroperitoneal liposarcomas. We are presenting a case of a 44-year-old female with a pathology proven case of retroperitoneal extra-adrenal myelolipoma that was initially diagnosed by imaging as a retroperitoneal liposarcoma. In this case report, the clinical presentation, imaging findings, operative details and histopathology features are illustrated.

Fat-containing Retroperitoneal Lesions: Imaging Characteristics, Localization, and Differential Diagnosis

The complex anatomy of the retroperitoneum is reflected in the spectrum of neoplastic and nonneoplastic conditions that can occur in the retroperitoneum and appear as soft-tissue masses. The presence of fat within a retroperitoneal lesion is helpful in refining the differential diagnosis. Fat is easily recognized because of its characteristic imaging appearance. It typically is hyperechoic at ultrasonography and demonstrates low attenuation at computed tomography (-10 to -100 HU). Magnetic resonance imaging is a more ideal imaging modality because it has better soft-tissue image contrast and higher sensitivity for depicting (a) microscopic fat by using chemical shift imaging and (b) macroscopic fat by using fat-suppression techniques. Whether a lesion arises from a retroperitoneal organ or from the soft tissues of the retroperitoneal space (primary lesion) is determined by examining the relationship between the lesion and its surrounding structures. Multiple imaging signs help to determine the organ of origin, including the "beak sign," the "embedded organ sign," the "phantom (invisible) organ sign," and the "prominent feeding artery sign." Adrenal adenoma is the most common adrenal mass that contains microscopic fat, while myelolipoma is the most common adrenal mass that contains macroscopic fat. Other adrenal masses, such as pheochromocytoma and adrenocortical carcinoma, rarely contain fat. Renal angiomyolipoma is the most common fat-containing renal mass. Other fat-containing renal lesions, such as lipoma and liposarcoma, are rare. Fatty replacement of the pancreas and pancreatic lipomas are relatively common, whereas pancreatic teratomas are rare. Of the primary retroperitoneal fat-containing lesions, lipoma and liposarcoma are common, while other lesions are relatively rare. (©)RSNA, 2016.

Radiologic-pathologic correlation in extra-adrenal myelolipoma

Myelolipoma is an uncommon benign tumor that classically arises in the adrenal glands. Most cases are asymptomatic, with incidental detection of this tumor on cross-sectional imaging performed for other causes. Extra-adrenal occurrence of myelolipoma has been infrequently reported, with scarce radiology literature on the topic. We present radiologic and pathologic correlation in two cases of image-guided biopsy proven extra-adrenal myelolipoma in the presacral and paraaortic location, with review of literature.

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

Background

Myelolipoma 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 presentation

We 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.

Conclusions

Literature 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.

Renal myelolipoma: a rare extra-adrenal tumor in a rare site: a case report and review of the literature

Introduction

Myelolipomas are uncommon, benign tumors composed of mature adipose tissue and hematopoietic elements. They mostly occur in the adrenal glands, but extra-adrenal myelolipomas have also been reported in other locations such as the presacral region, retroperitoneum, pelvis and mediastinum. Here, we present a case of an extra-adrenal myelolipoma in a rare site: the renal parenchyma. To the best of our knowledge, it is only the third case reported in this unusual location.

Case presentation

We report a case of primary myelolipoma occurring in the kidney of a 55-year-old Moroccan man. We describe the radiological and clinicopathologic features of this unusual tumor with a review of the literature, and we discuss differential diagnosis of retroperitoneal myelolipomas.

Conclusion

This case is noteworthy because the tumor site was unusual. Although renal myelolipoma is rare, it should be considered in the differential diagnosis of lesions in this site.

Imaging of uncommon retroperitoneal masses

Retroperitoneal masses not arising from major solid organs are uncommon. Although there is no simple method of classifying retroperitoneal masses, a reasonable approach is to consider the masses as predominantly solid or cystic and to subdivide these into neoplastic and nonneoplastic masses. Because the treatment options vary, it is useful to be able to differentiate these masses by using imaging criteria. Although the differential diagnosis of retroperitoneal masses can be narrowed down to a certain extent on the basis of imaging characteristics, patterns of involvement, and demographics, there is still a considerable overlap of imaging findings for these masses, and histologic examination is often required for definitive diagnosis. Computed tomography (CT) and magnetic resonance (MR) imaging play an important role in characterization and in the assessment of the extent of the disease and involvement of adjacent and distant structures. Familiarity with the CT and MR imaging features of various retroperitoneal masses will facilitate accurate diagnosis and staging for aggressive lesions.

Bilateral renal sinus myelolipomas

Adrenal myelolipomas are benign neoplasms consisting of hematopoietic cellular elements and adipose tissue. They are uncommon, found in 0.4% to 1% of the population at autopsy. Extra-adrenal myelolipomas (EM) are extremely rare with fewer than 50 cases reported. We describe the first case of bilateral EM of the renal sinus. They are difficult to diagnose on imaging alone when arising in this location and biopsies may not yield a definitive answer. Management options include both conservative and surgical approaches depending upon the certainty of the diagnosis, progression of the patient's symptoms and evidence of growth.

Functional and morphological imaging of extraadrenal myelolipoma

Myelolipoma is a rare, hormonally inactive, benign tumor consisting of fat and hematopoietic cells. It is often encountered in the adrenal gland. Less frequently, it may occur in extraadrenal sites. Although myelolipoma is well defined by criteria of morphologic imaging, functional characteristics may be crucial to exclude malignancy.We present a case of histologically proven extraadrenal myelolipoma which was successfully diagnosed by bone marrow scintigraphy, using a monoclonal antibody directed against myeloid elements.

Simultaneous adrenal and extra-adrenal myelolipoma - an uncommon incident: case report and review of the literature

Background

Extra-adrenal myelolipomas are rare benign tumours. Other soft tissue tumours such as well-differentiated liposarcomas appear morphological almost identical. Preoperative imaging and especially biopsy are important tools to diagnose these lesions.

Case presentation

We report a very seldom case of a simultaneous myelolipoma of the adrenal gland in association with an extra-adrenal myelolipoma in an 75-year-old man. With a review of the literature we describe and discuss the aetiology, differential diagnosis and treatment of patients with respect to adrenal and extra-adrenal lesions.

Conclusion

The appearance of a simultaneous adrenal and extra-adrenal myelolipoma is a rare incident. We conclude that such lesions should be considered in the differential diagnosis of a fat-containing tumour in the retroperitoneal tissue/compartment.