CNC patients may present different signs and symptoms including but not limited to:
- Atypical skin coloring (pigmentation)
Changes in skin pigmentation occur in more than 80% of patients. The most common are lentigines, which are brown skin patches that are characteristically found on the lips, inner and outer corners of the eyes, and around the genitals, but can be found all over the body. Lentigines usually increase in number after puberty.
- Myxomas
Myxomas are a type of benign tumor that can occur on the skin or heart, and rarely can occur on bone. Skin myxomas usually occur in the eyelid, nipples, and genitals. Heart myxomas can be found in any region of the heart. After removal, the myxomas tend to return.
- Tumors or overactivity of hormone producing (endocrine) glands
Affected hormone producing glands include the adrenals, thyroid, pituitary, testicles and/or ovaries. A tumor of the adrenal glands, known as primary pigmented nodular adrenal disease (PPNAD) is the most reported endocrine tumor in CNC patients. PPNAD causes a disease called Cushing syndrome, where the body produces the hormone cortisol in excess. Some signs and symptoms of Cushing syndrome are weight gain, easy bruising, and depression or mood changes. However, patients with CNC may have excess cortisol production without having these signs or symptoms. Tumors may also occur in the thyroid, testicles or ovaries, and less commonly in the pituitary.
- Psammamomatous Melanotic Schwannomas (PMS):
PMS is a rare tumor of the nervous system which may occur in up to 10% of CNC patients. Patients can be diagnosed with CNC when they have two or more of the major signs and symptoms listed above. The presence of a disease-causing variant in PRKAR1A can be used to confirm the diagnosis.