From the Guidelines
Embryonal carcinoma is histologically characterized by large, primitive-appearing cells with high nuclear-to-cytoplasmic ratios, prominent nucleoli, and indistinct cell borders, with positive immunohistochemical staining for SALL4, OCT3/4, and SOX2, as shown in Table 2 of the study by 1. The histological description of embryonal carcinoma includes:
- Large, primitive-appearing cells with high nuclear-to-cytoplasmic ratios
- Prominent nucleoli and vesicular chromatin
- Indistinct cell borders
- Abundant mitotic figures, reflecting high proliferative activity
- Scant cytoplasm that may appear clear or amphophilic
- Common findings of necrosis and hemorrhage within the tumor The tumor cells are arranged in various patterns, including:
- Solid sheets
- Glands
- Papillary structures
- Cords The immunohistochemical profile of embryonal carcinoma, as noted in the study by 1, typically includes positive staining for:
- SALL4
- OCT3/4
- SOX2 This profile helps distinguish embryonal carcinoma from other germ cell tumors, such as dysgerminoma and yolk sac tumor, and is essential for correct pathological diagnosis, as emphasized by 1.
From the Research
Histological Description of Embryonal Carcinoma
- Embryonal carcinoma is a histologic subgroup of testicular germ cell tumors (TGCTs) 2
- The cells of embryonal carcinoma may follow differentiation lineages in a manner similar to early embryogenesis 2
- Embryonal carcinoma cells are pluripotent stem cells derived from teratocarcinomas and are considered the malignant counterparts of human embryonic stem (ES) cells 3
- The histologic description of embryonal carcinoma includes the presence of undifferentiated tumor cells, which can be identified by the expression of pluripotency markers such as NANOG and POU5F1 (OCT3/4) 2
Key Features of Embryonal Carcinoma
- Embryonal carcinoma is characterized by the expression of genes associated with embryonic stem cells, such as GAL, DPPA4, and NALP7 2
- The tumor cells can differentiate into various lineages, including embryonic ectoderm 3
- Embryonal carcinoma is often associated with other types of germ cell tumors, such as seminomas and teratomas 4