Renal epithelioid angiomyolipoma with malignant features: Histological evaluation and novel immunohistochemical findings.
Renal epithelioid angiomyolipoma (EAML) is a potentially malignant tumor type whose characteristics and biomarkers predictive of malignant behavior have not been elucidated. Here, we report three cases of renal EAML with malignant features but without histories of tuberous sclerosis complex. Case 1 involved a 29-year-old man with a 12-cm solid mass in the right kidney who underwent radical right nephrectomy. Case 2 involved a 22-year-old woman with a retroperitoneal mass who underwent radical right nephrectomy and retroperitoneal tumorectomy. Local recurrence was detected 7 years post-surgery. Case 3 involved a 23-year-old man with a 14-cm solid mass in the left kidney who underwent radical left nephrectomy. Microscopically, the tumors in all cases demonstrated proliferation of epithelioid cells with atypia, mitotic activity, necrosis, hemorrhage, and vascular invasion. Epithelioid cells in all cases were immunohistochemically positive for melanocytic and myoid markers and weakly positive for E-cadherin and β-catenin. Immunohistochemistry revealed activation of the mammalian target of rapamycin pathway. Here, we report the morphological and immunohistochemical features of clinically or histologically malignant renal EAML.
Department of Pathology, Tohoku University Graduate School of Medicine, Sendai, Japan.
Sachiko
S
Konosu-Fukaya
Yasuhiro
Y
Nakamura
Fumiyoshi
F
Fujishima
Atsuko
A
Kasajima
Keely M
KM
McNamara
Yayoi
Y
Takahashi
Kensuke
K
Joh
Hideo
H
Saito
Naomasa
N
Ioritani
Yoshihiro
Y
Ikeda
Yoichi
Y
Arai
Mika
M
Watanabe
Hironobu
H
Sasano
D000328:Adult; D018207:Angiomyolipoma / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D014408:Biomarkers, Tumor / Q000378:metabolism; D015820:Cadherins / Q000378:metabolism; D015622:Epithelioid Cells / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D008297:Male; D009392:Nephrectomy; D016896:Treatment Outcome; D055815:Young Adult; D051176:beta Catenin / Q000378:metabolism
D014408:Biomarkers, Tumor; D015820:Cadherins; D051176:beta Catenin
E-cadherin; epithelioid angiomyolipoma; mTOR; malignant angiomyolipoma; β-catenin