**1.3 Components of neoplasms**

Tumors (both benign and malignant) consist of two basic components: **Microscopic:**

1.**Parenchyma:** It is made up of neoplastic cells. The nomenclature and biological behavior of tumors are based primarily on the parenchymal component of tumor. 2.**Stroma:** It is the supporting, nonneoplastic tissue derived from the host.


This type of inflammatory reaction may be acute, chronic, or rarely granulomatous reaction. Some tumors show inflammatory reactions even in the absence of ulceration. It is due to cell-mediated immunologic response of the host against the tumor in an attempt to destroy the tumor. For example, lymphocytes in the stroma are seen in seminoma testis and medullary carcinoma of the breast.

3.**Importance of stroma:** It is required for growth, survival, and replication of tumor (through blood supply) cells [1].
