Malignant Leydig cell tumor with spindle-shaped cells in a male CD-1 mouse.
Leydig cell tumors with spindle-shaped cells are very rare in humans and animals. We report that an 84-week-old male CD-1 mouse had a malignant Leydig cell tumor characterized by proliferation of oval to spindle-shaped cells with or without fat deposition, and with a storiform pattern. These cells were immunopositive for inhibin and S-100, and negative for the androgen receptor, thereby suggesting that they may have differentiated from Leydig cells. This differentiation from Leydig cells was further confirmed by the immunopositivity of these cells for nestin and alpha-smooth muscle actin, both of which are known to be expressed in the stem/progenitor cells that differentiate into Leydig cells. These findings suggest that the tumor is most probably a malignant spindle-cell-type Leydig cell tumor.
Ohnuma
Aya
A
Laboratory of Pathology, Toxicology Division, The Institute of Environmental Toxicology, Uchimoriya-machi 4321, Joso-shi, Ibaraki303-0043, Japan.
Yoshida
Toshinori
T
Takahashi
Naofumi
N
Akema
Satoshi
S
Kumagai
Mutsumi
M
Chiba
Yuko
Y
Kashimoto
Yukiko
Y
Kuwahara
Maki
M
Nakashima
Nobuaki
N
Harada
Takanori
T
D000818:Animals; D002467:Cell Nucleus / Q000473:pathology; D007150:Immunohistochemistry; D007984:Leydig Cell Tumor / Q000473:pathology* / Q000662:veterinary*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D012376:Rodent Diseases / Q000473:pathology; D014617:Vacuoles / Q000473:pathology