Case report: perinephric angiomyolipomas in tuberous sclerosis

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.

Retroperitoneal extrarenal angiomyolipomas: an evidence-based approach to a rare clinical entity

Extrarenal angiomyolipomas (ERAMLs) are rare tumors that present as incidentalomas upon imaging for other conditions. Retroperitoneal ERAMLs present a unique challenge from a diagnostic and treatment standpoint as they can mimic other benign and malignant retroperitoneal tumors. We present a case of a 39-year-old female with a 19.3 cm × 13.5 cm × 10.7 cm left extrarenal retroperitoneal mass. Histopathologic examination and HMB-45 staining revealed the mass to be a retroperitoneal ERAML. Our case report provides a comprehensive literature review and an evidence-based algorithm for taking care of patients with ERAMLs.

Computerized tomography characteristics that differentiate angiomyolipomas from liposarcomas in the perinephric space

PURPOSE

We performed a retrospective study to determine computerized tomography (CT) findings associated with perinephric angiomyolipomas or perinephric liposarcomas.

MATERIALS AND METHODS

During the last 7 years 6 patients with perinephric angiomyolipoma and 12 with perinephric liposarcoma were seen at our hospital. Two radiologists who were blinded to the pathological diagnosis retrospectively evaluated the CT characteristics of perinephric angiomyolipoma and perinephric liposarcoma. The relationship of each CT characteristic with tumor type was compared using Fisher's exact test.

RESULTS

The CT characteristics of perinephric angiomyolipoma were intratumoral linear vascularity (p = 0.001), aneurysmal dilatation (p = 0.025), bridging vessel sign (p = 0.005), hematoma (p = 0.025), beak sign (p = 0.001) and discrete intrarenal fatty tumors (p = 0.025). The CT characteristic of perinephric liposarcoma was a nonfatty soft tissue mass (p = 0.005). There was no significant difference in the presence of calcifications in both groups.

CONCLUSIONS

This retrospective study suggests that analysis of CT characteristics (linear vascularity, aneurysmal dilatation, bridging vessel sign, hematoma, beak sign and discrete intrarenal fatty tumors) may help to differentiate perinephric angiomyolipoma from perinephric liposarcoma.

Lymphangiectasia within angiomyolipoma in a tuberous sclerosis patient

This is a presentation of a case of tuberous sclerosis with multifocal hamartomas in the retroperitoneum, both kidneys, and the liver. Lymphangiectasia and numerous ectatic lymphatic channels penetrating through the retroperitoneal angiomyolipoma were demonstrated by lymphography and computed tomography. The findings in our study may document the presence of degenerative change in the lymphatic system--not just in elastic vessels--an association which has not yet been reported in the radiological literature.