Due to the chromosome 10 deletion involving contiguous portions of BMPR1A and PTEN in our patient, he may be at risk for CS associated cancers and features, in addition to the polyps associated with JPS.
A PTEN mutation, c.1003C>T p.(Arg335Ter), was subsequently identified as the cause of Cowden syndrome in another family member (a nephew) with dysplastic gangliocytoma of the cerebellum (Lhermitte-Duclos disease), and genetic testing in the proband's daughter indicated that he was an obligate carrier of the mutation.
We calculated the cost per mutation detected and analyzed the cost-effectiveness of performing selected PTEN testing among CS-like patients using a semi-quantitative score (the PTEN Cleveland Clinic [CC] score) compared with existing diagnostic criteria.
Germline alterations in phosphatase and tensin homolog (PTEN; PTEN_mut+), succinate dehydrogenase B/C/D (SDHB-D; SDHx_var+), and killin (KLLN_Me+) cause CS and Cowden syndrome-like (CSL) phenotypes.
Germline variants in SDHB/C/D (SDHx) genes account for subsets of CS/CS-like cases, conferring a higher risk of breast and thyroid cancers over those with only germline PTEN mutations.
Germline mutations in PTEN, which encodes a widely expressed phosphatase, was mapped to 10q23 and identified as the susceptibility gene for Cowden syndrome, characterized by macrocephaly and high risks of breast, thyroid, and other cancers.
This case report illustrates the unusual presentation of Ewing sarcoma in a patient with PTEN-mutant CS, the probable underlying molecular pathogenesis, long-term management, and therapeutic considerations.
Phosphatase and tensin homolog (PTEN) hamartoma tumor syndrome (PHTS) encompasses several rare disorders linked to mutations of the PTEN gene, including Cowden disease (CD) and Bannayan-Riley-Ruvalcaba syndrome (BRRS).
In addition, the differential PTEN mutation status with corresponding LDD phenotypes suggests a potential correlation between germline or somatic mutation and coexisting LDD/CS or isolated LDD, respectively.
PTEN gene analysis was performed and confirmed Cowden Syndrome, a rare genodermatosis with an autosomal dominant pattern of inheritance, characterized by multiple hamartomas.
Because loss of PTEN can activate mTOR and mTOR inhibitors are Food and Drug Administration approved to treat renal cell carcinoma, these agents have clinical potential in renal cell carcinoma associated with Cowden syndrome.