What type of tumor is characterized by the presence of Antoni A and Antoni B lines, and Verocay bodies?

The tumor characterized by the presence of Antoni A and Antoni B patterns, as well as Verocay bodies, is indeed a Schwannoma. Schwannomas, also known as neurilemomas, are benign tumors that arise from Schwann cells, which are responsible for the myelination of peripheral nerves.

Antoni A tissue is characterized by highly cellular areas with a compact arrangement of Schwann cells, often forming Verocay bodies, which are palisaded arrangements of nuclei around an acellular zone. In contrast, Antoni B tissue is less cellular and features a more loosely organized histological appearance, containing more myxoid or cystic change.

Identifying the presence of these specific histological features is critical for diagnosing Schwannomas in tissue samples. This knowledge helps differentiate Schwannomas from other tumors, like osteosarcoma, fibroma, or Ewing sarcoma, which do not exhibit the same distinct histological characteristics associated with Schwann cell tumors.