Pathology Outlines
Picture2
Submitted by Dr. G. Koteswaran, Professor of Pathology, MGMC&RI, Puducherry, India
Clinical History: A 51 year old woman with right lumbar pain had USG, showing a kidney mass. At surgery, the clinical impression was malignancy, and the mass was excised.
Gross: The kidney measured 9 x 6 x 2 cm with the attached mass at the lower pole on the posterior surface measured 9 x 7 x 3 cm. The mass had a thin capsule with blood vessels. On sectioning, the mass was yellowish and fatty, with dark brown streaks of vasculature. The kidney section showed a normal appearance with no invasion by the mass.
Microscopy showed predominantly fatty areas with scattered thin walled blood vessels, a few of which had a cuff of ovoid smooth muscle bundles. Occasional vessels had thrombosis in the lumen. The kidney itself was unremarkable. With these features, a diagnosis of angiomyolipoma involving the capsule was made.
Discussion: Angiomyolipoma is a rare neoplasm composed of fat, blood vessels and smooth muscle cells in varying proportions. Many cases have been reported in the kidney, liver and other sites. AML arising from the capsule is rare. Other capsular tumors are capsuloma, leiomyosarcoma, liposarcoma and myxoma. Awareness of AML in the capsule may prevent kidney removal.
References:
Case report of angiomyolipoma arising from capsule of kidney. Nihon Hinyokika Gakkai Zasshi. 1997 Nov;88(11):961-4, at www.ncbi.nlm.nih.gov/pubmed/9423311.
Case report of liposarcoma of renal capsule. Urol Int. 1992;48(2):223-5, at www.ncbi.nlm.nih.gov/pubmed/1585521.
Case report of myxoma of renal capsule. Pathol Res Pract. 2005;200(11-12):835-40, at www.ncbi.nlm.nih.gov/pubmed/15792129.
Picture2
Submitted by Dr. G. Koteswaran, Professor of Pathology, MGMC&RI, Puducherry, India
Clinical History: A 51 year old woman with right lumbar pain had USG, showing a kidney mass. At surgery, the clinical impression was malignancy, and the mass was excised.
Gross: The kidney measured 9 x 6 x 2 cm with the attached mass at the lower pole on the posterior surface measured 9 x 7 x 3 cm. The mass had a thin capsule with blood vessels. On sectioning, the mass was yellowish and fatty, with dark brown streaks of vasculature. The kidney section showed a normal appearance with no invasion by the mass.
Microscopy showed predominantly fatty areas with scattered thin walled blood vessels, a few of which had a cuff of ovoid smooth muscle bundles. Occasional vessels had thrombosis in the lumen. The kidney itself was unremarkable. With these features, a diagnosis of angiomyolipoma involving the capsule was made.
Discussion: Angiomyolipoma is a rare neoplasm composed of fat, blood vessels and smooth muscle cells in varying proportions. Many cases have been reported in the kidney, liver and other sites. AML arising from the capsule is rare. Other capsular tumors are capsuloma, leiomyosarcoma, liposarcoma and myxoma. Awareness of AML in the capsule may prevent kidney removal.
References:
Case report of angiomyolipoma arising from capsule of kidney. Nihon Hinyokika Gakkai Zasshi. 1997 Nov;88(11):961-4, at www.ncbi.nlm.nih.gov/pubmed/9423311.
Case report of liposarcoma of renal capsule. Urol Int. 1992;48(2):223-5, at www.ncbi.nlm.nih.gov/pubmed/1585521.
Case report of myxoma of renal capsule. Pathol Res Pract. 2005;200(11-12):835-40, at www.ncbi.nlm.nih.gov/pubmed/15792129.