Table 2 Pathologic characteristics of primary carcinoid tumor arising within mature teratoma of the kidney

Kojiro et al, 1976 [2]

Left/Polycystic with smooth and nodular external surface

NP/17

Mucous secretory glands, columnar epithelium, mature hyaline cartilage, smooth muscle

NP

Finely granular eosinophilic cytoplasm, uniform rounded nuclei with coarse chromatin and small nucleoli

0/10 HPF

NP

Fetissof et al, 1984 [3]

Right/Dilated sac filled with purulent exudate in horseshoe kidney with lower poles connected by broad isthmus

NP/2

Transitional and mucinous columnar epithelium with occasional cilia, smooth muscle, ossified chondroid plaques, nerve bundles with ganglion cells

Anastomosing ribbons intermixed with solid nests

NP

NP

SER⁺, GLU⁺, SOM⁺, ACTH^-, CAL^-, GAS^-, INS^-, MOT^-, NEU^-

Lodding et al, 1997 [1]

Right/Gray-white firm nodule in horseshoe kidney with broad connecting bridge in midline

Lower pole/2

Mature bone

Organoid

Uniform cells

NP

PCK⁺, NSE⁺, CHR⁺, SYN⁺, S-100⁺, SER⁺, PSA^-

Yoo et al, 2002 [4]

Left/Well circumscribed, tan-pink, glistening, focally hemorrhagic, primarily solid

Lower pole/3.5

Mucinous tall columnar epithelium, mature smooth muscle, mature bone

Anastomosing ribbons intermixed with solid nests

Monotonous small cells with finely stippled chromatin and inconspicuous nucleoli

0/10 HPF

PCK⁺, NSE⁺, CHR⁺

Kim et al, 2004 [5]

Right/Well defined solid, yellowish tan

Upper and mid poles/3.5

Mucinous columnar and pseudostratified columnar epithelium with occasional cilia, mature bone

Trabecular and anastomosing ribbons or nests

NP

NP

PCK⁺, NSE⁺, CHR⁺, SYN⁺

Kurzer et al, 2005 [6]

Right/Cyst filled with tan-brown friable material and three irregular tan-brown stones

Mid-lower pole/1

Transitional, colonic, squamous, and non-specific cuboidal epithelium, mature adipose, focal osseous metaplasia

Nests and cords

Small cells with peripheral palisading

NP

CHR⁺

Current case

Right/Cyst with irregular pale tan wall and focal calcifications

Middle pole/2

Urothelial-type and colonic epithelium, focal mature bone

Trabecular and anastomosing ribbon-like nests

Monotonous small round cells with peripheral palisading, and "salt-and-pepper" chromatin pattern

0/10 HPF

SYN⁺, CD 56⁺, PCK⁺, THY⁺, CK 7^-, CK 20^-, CAR^-, PR^-, ER^-, S-100^-, Melan-A^-, INS^-, TTF-1^-, CHR^-,