neoplasms

A neoplasm is an abnormal new growth of tissue resulting from neoplasia, characterized by autonomous, clonal proliferation that persists. Neoplasms arise when genetic and epigenetic alterations disrupt normal regulatory mechanisms governing cell growth and death. They can be benign or malignant. Benign neoplasms typically grow slowly, remain localized, and have well-defined borders; malignant neoplasms invade adjacent tissues and can metastasize to distant sites.

Most neoplasms are classified by tissue of origin: carcinomas arise from epithelial cells; sarcomas from connective tissues; leukemias and lymphomas from blood and lymphatic tissues; myelomas from plasma cells; germ cell tumors from reproductive cells. Benign neoplasms include adenomas, fibromas, lipomas, and osteomas; malignant neoplasms include carcinomas, sarcomas, and hematologic cancers.

Diagnosis involves clinical assessment, imaging, and tissue sampling. Histopathology is essential; immunohistochemistry and molecular tests refine classification and guide therapy. Staging uses systems such as TNM to describe extent and spread; grading assesses differentiation and aggressiveness.

Management is individualized and may involve surgery, radiation therapy, chemotherapy, targeted therapies, immunotherapy, and hormonal therapy. Early-stage neoplasms may be curable with local treatment; advanced cancers require systemic therapy and supportive care. Prognosis varies widely with type, stage, grade, patient health, and treatment response; prevention and early detection through risk reduction and screening play critical roles.