What Is a Follicular Neoplasm?

A neoplasm is a tumor, or growth, and a follicular neoplasm arises from what are called follicular cells inside the thyroid gland. The thyroid gland is located in front of the windpipe in the neck, and a large neoplasm may cause symptoms such as a hoarse voice or swallowing difficulties. Follicular lesions, or growths, may be nodules which form part of a non-cancerous, or benign, enlargement of the thyroid gland, known as a goiter. In other cases, they may be benign tumors called thyroid adenomas, or malignant, or cancerous, tumors known as thyroid carcinomas.

Growths in the thyroid gland may not be obvious at first, but could lead to symptoms such as a visible neck lump or problems with speech or swallowing. It can be difficult to distinguish between the different types of follicular neoplasm. A diagnostic test known as fine needle aspiration may be used to take a sample of cells, known as a biopsy, and the cells can then be studied under a microscope.

Even then, it might not be possible to know whether a follicular neoplasm is benign or malignant unless an operation is performed, allowing the surgeon to look at the whole of the growth. Inspecting the outer coat, or capsule, makes it possible to see whether the neoplasm is behaving like thyroid cancer by spreading out to invade surrounding tissue. When there is a risk that a follicular neoplasm might be malignant, it may be necessary to remove all or part of the thyroid gland to examine it further.

If follicular cancer is found, further surgery may not be required as the tumor will have already been removed. Where tumors are found to be benign adenomas or nodules, treatment may only be necessary if a lump is large enough to cause symptoms, or if it is producing excessive amounts of thyroid hormones. Following surgery, the thyroid hormones formerly produced by the gland may need to be replaced, as they regulate energy levels, temperature and other important functions. This is achieved by taking drugs containing synthetic or natural thyroid hormone; treatment is lifelong. Taking thyroid hormones after cancer has been removed has another benefit in that it discourages any remaining thyroid tissue from growing, lowering the risk of cancer recurrence.

Other possible treatments for follicular thyroid cancer include taking radioactive iodine. The iodine is taken into thyroid cells and its radioactivity destroys them. This treatment is used following removal of the thyroid gland, in order to get rid of any remaining thyroid tissue, or in cases where the cancer has spread to other parts of the body. The outlook for someone with a follicular neoplasm is often positive, because most are benign and, even when follicular cancer is discovered, in most cases a cure is possible with treatment.