A father and son with Turcot's syndrome: evidence for autosomal dominant inheritance: report of two cases

Possible Considerations for the Management of Turcot’s Syndrome?

Background:

Turcot’s syndrome (TS) is a rare disease with known incidence of about 1-2 cases per year. It is, however, linked to high mortality due to the brain cancer. And because of this, we propose recommendations, aimed at preventing the mortality of the patients and to minimize the risk of undiagnosed Turcot’s syndrome.

Methods:

The authors collected the worldwide published data on TS, from the year of its definition till 2018, all of which was published on the search engines, such as Medline, Medknow, Cohraine and Wiley.

Results:

We included 97 patients, 57 from which are females and 40 males with median age of 22 years. The most common type of cancer is medulloblastoma, followed by glioblastoma and astrocytoma. We further divided the patients into two categories based on the first symptom of the disease and we made an algorithm of approaching these patients.

Conclusion:

TS is a disease that affects mostly members of families with multiple genetic mutations and types of cancers. And because of the unknown mechanisms of inheritance, it is useful to establish guidelines for the approach of those patients, in order to minimize the high mortality rate.

[Muir-Torre syndrome and Turcot syndrome]

INTRODUCTION

Lynch syndrome (LS) is a syndrome that carries a genetic predisposition to certain cancers associating, either in a single individual or in a family, a visceral tumour, mainly colorectal, with a high risk of other synchronous or metachronous cancers. LS is linked with mutations in the genes coding for proteins in the DNA repair system. Phenotypic variants of SL exist, including Muir-Torre syndrome (MTS) and Turcot syndrome (TS), both of which predispose to colorectal cancer. They may be distinguished by the presence of benign or malignant sebaceous tumours in MTS, and tumours of the central nervous system in TS.

PATIENTS AND METHODS

A 59-year-old man, with a history of right colon cancer at the age of 36 years, consulted for a nose lesion shown by histopathological examination to be a sebaceous tumour. Immunohistochemistry revealed loss of expression of proteins MSH2 and MSH6, strongly suggesting a diagnosis of MTS. Eight years earlier, the man's son had developed a fatal glioblastoma; given the paternal phenotype of MTS, the hypothesis of TS in the son is probable.

DISCUSSION

This case suggests that several variants of Lynch syndrome may be seen within the same family. It raises the issue of screening for cerebral tumours in patients with MTS and in their family members, even though such a recommendation does not exist; current recommendations in fact consist primarily of gastrointestinal and gynaecological monitoring.

Turcot's syndrome associated with intestinal non-Hodgkin's lymphoma: case report and review of literature

A 15-year-old boy was admitted with the diagnosis of colonic polyposis, and during a 2-year follow-up, he underwent operation for right parieto-occipital anaplastic astrocytoma, left-side colonic non-Hodgkin lymphoma (NHL) and cerebella glioblastoma which were all confirmed by histology. Although cases of Turcot's syndrome (TS) (colonic polyposis and primary brain tumour occurring in the same patient) have been previously described, association with haematological malignancy is rare. We hereby report such a case with TS.

Pinealoblastoma in a patient with familial adenomatous polyposis: variant of Turcot syndrome type 2? Report of a case and review of the literature

We report a case of a 23-year-old Turcot female patient who was first diagnosed as having a pinealoblastoma. Thyroid papillary carcinoma was diagnosed a few months later, and multiple colonic polyps were detected three years after that. A genetic workup revealed an APC gene mutation in her family. Long-term survival (i.e., >5 years) of pinealoblastoma is considered to be 20 percent. A review of 25 documented Turcot cases determined that the average age at death is 20.3 years, raising the difficult question of whether she should undergo restorative proctocolectomy. Restorative proctocolectomy may itself cause major morbidity but is currently the only way to prevent colon cancer.

An unusual case of Turcot’s syndrome associated with ileal adenocarcinoma, intestinal non-Hodgkin’s lymphoma, and duodenal adenocarcinoma. Review of the classification and genetic basis of Turcot’s syndrome

A 38-year-old man with a history of colonic and small bowel polyposis and glioblastoma was investigated for dyspepsia. Upper GI endoscopy identified an abnormal area in the duodenum, confirmed by histology as high grade non-Hodgkin's B cell MALT lymphoma. Although cases of Turcot's syndrome (TS) (colonic polyposis and primary brain tumour occurring in the same patient) have been previously described, association with haematological malignancy is rare. This is the first report of intestinal lymphoma occurring in an adult with TS.

Turcot syndrome in an elderly adult

A 67-year-old woman presented with hematochezia and an episode of transient expressive dysphasia. She was found to have multiple colonic polyps with adenocarcinomatous changes. Computed tomography brain scan and computed tomography-guided biopsy revealed a left frontoparietal glioblastoma multiforme. This case illustrates the rare presentation of Turcot syndrome-a hereditary colorectal polyposis syndrome-in an older adult.

Evidence for a recessive inheritance of Turcot's syndrome caused by compound heterozygous mutations within the PMS2 gene

Turcot's syndrome is a genetic disease characterized by the concurrence of primary brain tumors and colon cancers and/or multiple colorectal adenomas. We report a Turcot family with no parental consanguinity, in which two affected sisters, with no history of tumors in their parents, died of a brain tumor and of a colorectal tumor, respectively, at a very early age. The proband had a severe microsatellite instability (MIN) phenotype in both tumor and normal colon mucosa, and mutations in the TGFbeta-RII and APC genes in the colorectal tumor. We identified two germline mutations within the PMS2 gene: a G deletion (1221delG) in exon 11 and a four-base-pair deletion (2361delCTTC) in exon 14, both of which were inherited from the patient's unaffected parents. These results represent the first evidence that two germline frameshift mutations in PMS2, an MMR gene which is only rarely involved in HNPCC, are not pathogenic per se, but become so when occurring together in a compound heterozygote. The compound heterozygosity for two mutations in the PMS2 gene has implications for the role of protein PMS2 in the mismatch repair mechanism, as well as for the presymptomatic molecular diagnosis of at-risk family members. Furthermore, our data support and enlarge the notion that high DNA instability in normal tissues might trigger the development of cancer in this syndrome.