Light microscopy histology of a gestational trophoblastic neoplasm, specifically choriocarcinoma, using hematoxylin and eosin staining. The sampled tissue from the uterus shows a biphasic trophoblastic proliferation with intermixed cytotrophoblasts and syncytiotrophoblasts embedded in a hemorrhagic background. Cytotrophoblasts are mononucleated with clear to pale pink cytoplasm, distinct cell borders, irregular oval to elongate nuclei, prominent nucleoli, and brisk mitotic activity. They form plexiform aggregates and villous-like structures lacking stromal cores. Syncytiotrophoblasts are large, multinucleated or polyploid cells with abundant deeply eosinophilic cytoplasm and nuclei displaying dense, smudgy chromatin; they extend cytoplasmic processes around cytotrophoblast nests and infiltrate clumps of trophoblast. The interplay between these two cell types creates a biphasic architecture characteristic of choriocarcinoma, often accompanied by extensive hemorrhage and necrosis. The tumor lacks organized placental stromal support and shows high cellular pleomorphism and mitotic rate. Clinically, these histologic features support a diagnosis of gestational choriocarcinoma with high malignant potential and propensity for early hematogenous spread. The finding is diagnostic when coupled with elevated serum beta-hCG and pertinent clinical history. Potential uses include confirmation of diagnosis, prognostic assessment, and guidance of chemotherapy regimens for GTN. The description also informs differential considerations from PSTT or epithelioid trophoblastic tumor. Staging.

Histopathology image, prepared as a hematoxylin and eosin (H&E) stained tissue section, depicting choriocarcinoma within endometrial/uterine tissue. The lesion displays islands of viable malignant trophoblastic cells embedded in extensive hemorrhage and coagulative necrosis. Trophoblastic proliferation is biphasic, with cytotrophoblasts forming polygonal nests and clusters and syncytiotrophoblasts showing multinucleated, eosinophilic cytoplasm adjacent to fragile hemorrhagic stroma. Nuclear atypia and brisk mitotic activity are evident in viable foci. The surrounding matrix is fibromyxoid with necrotic debris and residual vascular channels, reflecting aggressive, vascular tumor growth. The lack of well-formed villi distinguishes choriocarcinoma from other gestational trophoblastic lesions. Areas of extensive hemorrhage contribute to the gross appearance of reddish, necrotic tissue in vivo. In immunohistochemistry, tumor cells typically express human chorionic gonadotropin (hCG) and cytokeratins, supporting trophoblastic lineage; p63 or inhibin may be variably positive, depending on subtype. Clinically, this histology corresponds to a highly vascular, metastasis-prone neoplasm that requires prompt evaluation of serum hCG levels and imaging for metastatic disease. The diagnostic significance lies in distinguishing choriocarcinoma from non-neoplastic gestational tissue and other germ cell tumors, guiding management including chemotherapy and monitoring for beta-hCG decline. This image is illustrative for educational reference, highlighting histologic hallmarks and diagnostic pitfalls in trophoblastic neoplasia today.

This diagnostic image composite displays pelvic Magnetic Resonance Imaging (MRI) findings in a case of Gestational Trophoblastic Neoplasia (GTN), likely an invasive mole or choriocarcinoma. Panels A, B, and C are T2-weighted sequences in axial, coronal, and sagittal planes, respectively. They reveal an enlarged uterus containing a bulky, heterogeneous tissue mass that extensively invades the myometrium (indicated by arrows). The sagittal view (C) demonstrates downward locoregional extension into the vaginal wall (arrowhead) and the labia majora (star symbol). Panels D and E show post-gadolinium T1-weighted axial images with fat saturation. These images exhibit a markedly heterogeneous enhancement pattern throughout the uterine mass. Prominent, well-demarcated non-enhancing zones are visible within the lesion, characteristic of necrotic regions common in rapidly growing trophoblastic tumors. The imaging highlights the aggressive, hypervascular nature of the tumor and its capacity for deep structural invasion into the pelvic floor, serving as a critical tool for FIGO staging and treatment planning in gynecologic oncology.