Riley-Smith Syndrome

At a glance

A rare malformation syndrome characterized by Macrocephaly, Autosomal dominant, Thyroid disease, Cancer, Hamartomata, Skin abnormalities (MATCHS) and due to mutations of the PTEN tumor suppressor gene (an acronym that stands for Phosphatase and TENsin homolog deleted on chromosome TEN). Multiple hemangiomata and lipomas. Subcutaneous hemangioma may be present at birth or appear later in childhood.

Synonyms

Macrocephaly Multiple Lipomas and Hemangio­mata Syndrome; Macrocephaly, Pseudopapilledema and Multi­ple Hemangiomata Syndrome; Rovsing Syndrome; Bannayan-Riley-Ruvalcaba Syndrome; Bannayan-Zonana Syndrome.

History

First described in 1986 as a different disease. It has been proposed that the three medical conditions: Bannayan-Zonana Syndrome, the Riley-Smith Syndrome, and the Ruvalcaba-Myhre-Smith Syndrome are similar entities and should be most appropriately represented as the Bannayan-Riley-Ruvalcaba Syndrome.

Genetic inheritance

Autosomal dominant.

Incidence

Not known. Male predominance. However, females can be affected, although in a milder form which explains why it remains mostly undiagnosed.

Pathophysiology

Results from mutations in the phosphatase and tensin homologue (PTEN) gene. Gene map location is 10q23.3. The homologies displayed by the structure of PTEN suggested to the investigators that it may suppress tumor cell growth by antagonizing protein tyrosine kinases and that it may regulate tumor cell invasion and metastasis through interactions at focal adhesions.

Diagnosis

Clinical. It is based on the association of macrocephaly, multiple lipomas, intestinal hamartomatous polyps, vascular malformations, and abnormal pigmentation of the penis. The definite diagnosis is determined genetically.

Clinical aspects

Multiple signs can be observed with relative frequencies: head anomalies (macrocephaly, scaphocephaly, down-slanting palpebral fissures, strabismus, amblyopia, prominent Schwalbe lines, hypertelorism, exotropia, pseudopapilledema tongue, polyps, high-arched palate), chest anomalies (pectus excavatum, supernumerary nipples), genital anomalies (enlarged penis, enlarged testis), abdominal anomalies (ileal hamartomatous polyps, colonic hamartomatous polyps, intussusceptions, rectal bleeding), neurological anomalies (hypotonia, seizures, thick corpus callosum, intracranial hemangioma), orthopedic anomalies (scoliosis, joint hyperextensibility, macrodactyly), and dermatological lesions (tan macules on the glans and the shaft of the penis, acanthosis nigricans, angiokeratoma, café-au-lait spots, lipomas, hemangiomas, cutis marmorata). The lipomas spontaneously regress with age. Motor and speech development are delayed, mild mental retardation, and incoordination are lifelong features. A myopathy caused by abnormal lipid storage can occur with proved muscle carnitine deficiency. Patients may have an increased risk of intracranial tumors. An increased incidence of Hashimoto thyroiditis has been suggested.

Precautions before anesthesia

The presence of brain edema and raised intracranial pressure must be assumed until proven otherwise. Proper evaluation of the neurological functions, including CT scan must be obtained before anesthesia. It is essential to check the hemoglobin level and coagulation profile because of the risk of bleeding from ...