Neoplastic tumor of the cheek skin, here a benign neoplasm of the sweat glands called Hidradenoma.

A tumor or tumour is the name for a swelling or lesion formed by an abnormal growth of cells (termed neoplastic). Tumor is not synonymous with cancer. A tumor can be benign, pre-malignant or malignant, whereas cancer is by definition malignant.

Etymology

The term tumor is derived, via the Old French tumour, from the Latin tumor "swelling".^[1] It originally meant an abnormal swelling of the flesh. In contemporary English, tumor is synonymous with solid neoplasm ^[2], all other forms of swelling being called swelling.^[3] This usage is common also in medical literature, where the nouns tumefaction and tumescence, derived from the adjective tumefied, are the current medical terms for non-neoplastic swelling.^[4]

Cause

A neoplasm is an abnormal proliferation of tissues, usually caused by genetic mutations. Most neoplasms cause a tumor, with a few exceptions like leukemia or carcinoma in situ.

Tumors may be benign, pre-malignant or malignant (cancer). The nature of the tumor is determined by a pathologist after examination of the tumor tissues from a biopsy or a surgical excision specimen.

References

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