Fat-poor angiomyolipoma with cyst-like changes mimicking a cystic renal cell carcinoma: a case report.
Angiomyolipoma is a common benign renal tumor. It is typically composed of adipose tissue and hence is easily diagnosed by using imaging methods such as ultrasonography, computed tomography, and magnetic resonance imaging. However, it is difficult to differentiate an atypical angiomyolipoma such as a fat-poor angiomyolipoma from a malignant tumor by using these imaging methods. We report a case of a fat-poor angiomyolipoma with cyst-like changes in a 35-year-old man. The angiomyolipoma was initially suspected to be a cystic renal cell carcinoma according to preoperative imaging studies. A 5-cm cystic tumor with an enhanced septal wall and exophytic formation was present in the middle section of the left kidney. The patient underwent partial nephrectomy. Pathological findings showed necrosis and hematoma in almost the entire lesion, with a small amount of adipose and muscle tissue. Finally, a fat-poor angiomyolipoma was diagnosed.
Department of Urology, Tokyo Women's Medical University, 8-1, Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan. yuuki09078375941@yahoo.co.jp.
Yuki
Y
Kobari
Department of Urology, Tokyo Women's Medical University, 8-1, Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan. t.takagi1192@gmail.com.
Toshio
T
Takagi
Department of Urology, Tokyo Women's Medical University, 8-1, Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan. tkondo@kc.twmu.ac.jp.
Tsunenori
T
Kondo
Department of Urology, Tokyo Women's Medical University, 8-1, Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan. tachi6ana@yahoo.co.jp.
Hidekazu
H
Tachibana
Department of Urology, Tokyo Women's Medical University, 8-1, Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan. setogawacho@yahoo.co.jp.
Shoichi
S
Iida
Department of Diagnostic Imaging and Nuclear Medicine, Tokyo Women's Medical University, Tokyo, Japan. nishina.yu@twmu.ac.jp.
Yu
Y
Nishina
Department of Urology, Tokyo Women's Medical University, 8-1, Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan. oranz416@hotmail.com.
Kenji
K
Omae
Department of Diagnostic Imaging and Nuclear Medicine, Tokyo Women's Medical University, Tokyo, Japan. I@imodey.com.
Satoru
S
Morita
Department of Surgical Pathology, Tokyo Women's Medical University, Tokyo, Japan. sheto@research.twmu.ac.jp.
Tomoko
T
Yamamoto
Department of Urology, Tokyo Women's Medical University, 8-1, Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan. Jpiizuka@gmail.com.
Junpei
J
Iizuka
Department of Surgical Pathology, Tokyo Women's Medical University, Tokyo, Japan. nagashima.yoji@twmu.ac.jp.
Yoji
Y
Nagashima
Department of Urology, Tokyo Women's Medical University, 8-1, Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan. K-tanabe@k3.dion.ne.jp.
Kazunari
K
Tanabe
D000273:Adipose Tissue / Q000473:pathology*; D000328:Adult; D018207:Angiomyolipoma / Q000150:complications / Q000175:diagnosis* / Q000601:surgery; D002292:Carcinoma, Renal Cell / Q000150:complications / Q000175:diagnosis* / Q000601:surgery; D003560:Cysts / Q000473:pathology* / Q000601:surgery; D003937:Diagnosis, Differential; D006801:Humans; D007680:Kidney Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D009392:Nephrectomy; D011379:Prognosis; D014057:Tomography, X-Ray Computed