Carcinoid tumor of the renal pelvis: consideration on the histogenesis.
Carcinoid tumor of the renal pelvis is an extremely rare neoplasm and only two cases have been previously reported in the English-language literature. Reported herein is a third case of carcinoid tumor arising in the renal pelvis. The tumor extending from the left renal pelvis into the left kidney was incidentally found in a 55-year-old Japanese woman. Macroscopically, the tumor was predominantly located in the dilated renal pelvis and was grayish-white on cut surface. Microscopically, neoplastic cells proliferated with a ribbon-like, trabecular, tubular and solid pattern. Furthermore, the tumor focally invaded the kidney parenchyma. No precursor lesion of neuroendocrine tumor was observed in the peripheral urothelial epithelium. Neither urothelial carcinoma nor teratoma component was observed within the tumorous mass. The cytoplasm of neoplastic cells was focally positive for Grimelius stain and focally positive for chromogranin A and synaptophysin. However, no neoplastic cells reacted with cytokeratins 7 and 20. Ultrastructurally, neoplastic cells contained dense core granules in the cytoplasm. Urologists and pathologists should recognize that carcinoid tumor may arise from the renal pelvis.
Kuroda
Naoto
N
Department of Diagnostic Pathology, Kochi Red Cross Hospital, Kochi City, Japan. nkurodakrch@yahoo.co.jp
Katto
Kazunobu
K
Tamura
Masato
M
Shiotsu
Tomoyuki
T
Hes
Ondrej
O
Michal
Michal
M
Nagashima
Yoji
Y
Ohara
Masahiko
M
Hirouchi
Takashi
T
Mizuno
Keiko
K
Hayashi
Yoshihiro
Y
Lee
Gang-Hong
GH
D002276:Carcinoid Tumor / Q000378:metabolism / Q000648:ultrastructure*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007680:Kidney Neoplasms / Q000378:metabolism / Q000648:ultrastructure*; D007682:Kidney Pelvis / Q000378:metabolism / Q000648:ultrastructure*; D046529:Microscopy, Electron, Transmission; D008875:Middle Aged