Carney complex (CNC) is characterized by skin pigmentary abnormalities, myxomas, endocrine tumors or overactivity, and schwannomas. Pale brown to black lentigines are the most common presenting feature of CNC and typically increase in number at puberty. Cardiac myxomas occur at a young age, may occur in any or all cardiac chambers, and can manifest as intracardiac obstruction of blood flow, embolic phenomenon, and/or heart failure. Other sites for myxomas include the skin, breast, oropharynx, and female genital tract. Primary pigmented nodular adrenocortical disease (PPNAD), which causes Cushing syndrome, is the most frequently observed endocrine tumor in CNC, occurring in approximately 25% of affected individuals. Large-cell calcifying Sertoli cell tumors (LCCSCTs) are observed in one third of affected males within the first decade and in most adult males. Up to 75% of individuals with CNC have multiple thyroid nodules, most of which are nonfunctioning thyroid follicular adenomas. Clinically evident acromegaly from a growth hormone (GH)-producing adenoma is evident in approximately 10% of adults. Psammomatous melanotic schwannoma (PMS), a rare tumor of the nerve sheath, occurs in an estimated 10% of affected individuals. The median age of diagnosis is 20 years.

Schwannomatosis is characterized by a predisposition to develop multiple schwannomas and, less frequently, meningiomas. Individuals with schwannomatosis most commonly present between the second and fourth decade of life. The most common presenting feature is localized or diffuse pain or asymptomatic mass. Schwannomas most often affect peripheral nerves and spinal nerves. Meningiomas occur in about 5% of individuals with schwannomatosis and have only been reported in individuals with SMARCB1-related schwannomatosis. Malignancy remains a theoretic risk especially in individuals with a SMARCB1 pathogenic variant.

Tumor predisposition syndrome-2 (TPDS2) is an autosomal recessive cancer predisposition syndrome characterized by the onset of various types of tumors or malignancies in young adulthood. The most common clinical manifestations include acute myeloid leukemia (AML), myelodysplastic syndrome, colorectal adenomatous polyposis and carcinoma, and uveal melanoma, although other tumors and malignancies have been reported (summary by Palles et al., 2022). For a discussion of genetic heterogeneity of TPDS, see TPDS1 (614327).