Giant Extrarenal Retroperitoneal Angiomyolipoma: A Case Report and Literature Review

A Large Retroperitoneal Liposarcoma Mimicking an Angiomyolipoma on Pre-operative Imaging: A Case Report

Retroperitoneal masses present a diagnostic challenge due to their elusive origin and varied clinical manifestations. Among these masses, retroperitoneal liposarcomas, rare tumors of mesenchymal origin, often grow asymptomatically until compressing surrounding structures, necessitating accurate and early diagnosis. Renal angiomyolipomas (AMLs) have also been reported to mimic retroperitoneal liposarcomas on radiographic imaging, further complicating diagnostic processes. The presented case report describes a rare instance of a large well-differentiated liposarcoma that mimicked a renal angiomyolipoma on imaging in a 58-year-old male patient. The patient initially presented with worsening abdominal distension, early satiety, and left-sided flank pain for the past year. Radiographic imaging revealed a large mixed echogenic lesion measuring 22 x 13 cm in the left kidney with diffuse fat contribution, suspected to be a giant renal angiomyolipoma. The patient underwent selective arterial embolization by interventional radiology. Follow-up imaging eight months later showed an increase in the size of the mass, raising suspicion of a liposarcoma. Surgical resection of the mass and a radical left nephrectomy were performed, with final pathology confirming the diagnosis of a well-differentiated liposarcoma. This case highlights the importance of accurate diagnosis and the potential for liposarcomas to mimic other masses on imaging, despite their rarity.

Intricacy in the Diagnosis of Retroperitoneal Angiomyolipoma: A Rare Case

An uncommon benign mixed mesenchymal tumor called extrarenal retroperitoneal angiomyolipoma (ERAML) comprises thick-walled blood vessels, smooth muscle cells, and mature fat cells. Angiomyolipoma often develops in the kidneys, with extrarenal locations being uncommon. Many angiomyolipomas are unintentionally discovered when a person undergoes other medical issues. A 35-year-old man presented with a history of difficulty breathing and was on antibiotics. On follow-up, CT revealed a 22.5 × 14.3 × 8.6 cm right retroperitoneal mass. The retroperitoneal mass was resected en bloc at laparotomy and sent for histopathological examination. The grossly resected specimen was a smooth, well-circumscribed, yellowish-red retroperitoneal mass measuring 23 × 15 × 9 cm. The microscopic section reveals a tumor with prominent blood vessels and fatty tissue composed of spindle cells arranged into fascicles. The final diagnosis for this case is ERAML, which was challenging to distinguish from liposarcoma.

Left atrial myxoma: Unusual presentation as a cystic tumor

Myxomas are the most common cardiac tumors, benign, and usually located in the left atrium. Typically echocardiography reveals a solid tumor, whereas cystic myxomas are rare with only a few cases documented in the literature. We describe the case of a 63-year-old, female patient with an unusual presentation of a left atrial myxoma as a cystic tumor.

Retroperitoneal extrarenal angiomyolipoma at the surgical bed 8 years after a renal angiomyolipoma nephrectomy: A case report and review of literature

Retroperitoneal extrarenal angiomyolipoma (RERAML) are rare and close mimickers of retroperitoneal liposarcoma on both imaging and histopathology. However, imaging findings including heterogeneity, hyperdensity on unenhanced computed tomography, intralesional hemorrhage, absence of calcifications, low signal intensity on T2-weighted magnetic resonance imaging, and dilated intratumoral vessels can lead to the diagnosis of RERAML. Diagnosis of RERAML can avoid unnecessary surgery since conservative medical management with continued surveillance has been proven to be effective for RERAML whereas surgical resection is the treatment for liposarcoma. Imaging and laboratory follow-up for at least 5 years has been recommended in patients who underwent surgical resection of angiomyolipoma (AML). We present a case of RERAML in an asymptomatic patient whose AML recurred in the surgical bed 8 years after an ipsilateral nephrectomy for renal AML.

A Review of the Literature on Extrarenal Retroperitoneal Angiomyolipoma

BACKGROUND

Extrarenal retroperitoneal angiomyolipomas are rare.

AIM

To review the literature.

RESULTS

Angiomyolipomas, previously classified as hamartomas, are now classified as benign tumours. Thirty cases of primary retroperitoneal angiomyolipomas have been reported. Diagnosis of the disease upon is based radiological and pathological findings of triphasic features of (a) fat and (b) blood vessels and myoid tissue. Immunohistochemistry tends to be positive for HMB45, MART1, HHF35, calponin, NKI-C3, and CD117. The lesion is common in women. Treatment options have included the following: (a) radical surgical excision of the lesion with renal sparing surgery or radical nephrectomy in cases where malignant tumours could not be excluded and (b) selective embolization of the lesion alone or prior to surgical excision. One case of retroperitoneal angiomyolipoma was reported in a patient 15 years after undergoing radical nephrectomy for angiomyolipoma of kidney and two cases of distant metastases of angiomyolipoma have been reported following radical resection of the tumour.

CONCLUSIONS

With the report of two cases of metastases ensuing surgical resection of the primary lesions there is need for academic pathologists to debate and review angiomyolipomas to decide whether to reclassify angiomyolipomas as slow-growing malignant tumours or whether the reported cases of metastases were de novo tumours or metastatic lesions.

Giant renal angiomyolipoma: unusual cause of huge abdominal mass

We present the imaging and histopathological characteristics of a giant renal angiomyolipoma (AML) in a 49-year-old female patient, who presented with bloating sensation in the abdomen and a steadily increasing abdominal girth for about 3 years. Contrast enhanced computed tomography (CECT) scan films of abdomen revealed that a large fat containing tumor had replaced the left kidney while displacing the rest of the abdominal contents toward the other side of the midline. Intraoperatively the left kidney was completely replaced by a fat containing tumor. The recovered surgical specimen measured 39 cm × 25 cm × 9 cm and weighed 7500 g. Histopathological investigation with immuno-histochemical staining of the specimen with hydroxy beta-methylbutyric acid-45 confirmed this lesion as AML. CECT scan of the head did not show any lesion suggestive of tuberous sclerosis. The giant tumor of the present case is the heaviest AML in both syndromic and sporadic categories and largest by dimensions as sporadic AML ever reported in the literature.