Both samples show mature bony trabeculae and intervening marrow spaces that are focally infiltrated by mostly crushed malignant epithelial neoplasm (Block B). The tumor cells are predominantly arranged in distinct solid sheets, cords and single forms. The neoplastic cells exhibit moderate to marked nuclear atypia, characterized by enlarged, pleomorphic, and hyperchromatic nuclei with prominent nucleoli and a moderate amount of eosinophilic to amphophilic cytoplasm. Desmoplastic stromal reaction is noted in the intervening stroma. Picture is consistent with metastatic high grade undifferentiated carcinoma.
Given the patient's age, the primary differential diagnosis favors metastatic prostate carcinoma, followed by metastasis from the lung or gastrointestinal tract. The following panel is recommended to confirm the primary origin: PSA NKX3.1, TTF-1, Napsin A, CK7, CK20, and CDX2.
Two-week history of lower back pain and rapidly progressing lower limb paraplegia. MRI of the spine reveals a posterior epidural solid mass at the D3-D4 level causing significant spinal cord compression.
Two biopsies were received :
1- Bone fragments collectively measured 6.5x6x1 cm, totally embedded.
2- Bone fragments collectively measured 4x3.5x0.8 cm, totally embedded.
Thoracic spine (D3-D4) epidural mass, biopsy: