A heterogeneous appearance of the thyroid gland indicates the surface of the gland appears somewhat uneven; neither uniform nor smooth in appearance, according to HealthTap contributors. Such an appearance of the thyroid can suggest the gland may be host to nodules; most are common and benign.
While nodules may be detected in an ultrasound examination or thyroid scan, it does not determine whether the gland is overactive, underactive or normal in function, according to the U.S. National Library of Medicine. An abnormal appearance is not always a serious cause for concern; thyroid cancer accounts for only a small percentage of present thyroid nodules.
While many nodules do not carry any signs or symptoms, others may become increasingly visible, pressing on the windpipe or esophagus to cause shortness of breath or difficulty swallowing. In some cases, thyroid nodules produce additional thyroxine, -a hormone secreted by the thyroid gland- that may lead to unexplained weight loss, intolerance to heat, tremors, nervousness and rapid or irregular heartbeat, explains Mayo Clinic.
Causes of a heterogeneous appearance include: overgrowth of normal thyroid tissue, thyroid cyst, chronic inflammation, multi-nodular goiter and thyroid cancer. While size is not always an accurate predictor of cancerous nodules cancerous thyroid tumors are more likely to be large masses that grow quickly, cites Mayo Clinic