[1] The term GCNIS was introduced with the 2016 edition of the WHO classification of urological tumours.

[3] The World Health Organization classification of testicular tumours[4] subdivides ITGCN into (1) a more common, unspecified type (ITGCNU), and (2) other specific subtypes.

Microscopic examination of affected testicular tissue most commonly shows germ cells with enlarged hyperchromatic nuclei with prominent nucleoli and clear cytoplasm.

These cells are typically arranged along the basement membrane of the tubule, and mitotic figures are frequently seen.

Immunostaining with placental alkaline phosphatase (PLAP) highlights GCNIS cell membranes in 95 percent of cases.