Turcot's syndrome. Evidence for autosomal dominant inheritance

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.

A novel APC gene mutation associated with a severe phenotype in a patient with Turcot syndrome

Turcot syndrome is a rare inherited condition of colonic polyposis associated with central nervous system tumors. We report a patient with a novel adenomatous polyposis coli gene mutation leading to a severe phenotype including medulloblastoma, low-grade fibromyxoid sarcoma following cranial radiation, pilomatrixomas, colonic adenomas, and abdominal desmoid tumor following colectomy, all of which were successfully treated. Multiple tumors may be seen in patients with Turcot syndrome but the occurrence of sarcomas is rare. This case highlights the importance of close follow-up for patients with Turcot syndrome and the importance of a broad differential diagnosis in evaluating a condition in which multiple tumors are frequently seen.

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.

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.

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.

Turcot syndrome with colonic obstruction and small intestinal invagination: report of a case

We report herein the case of a 16-year-old boy diagnosed as having Turcot syndrome, otherwise known as glioma-polyposis syndrome. The patient was transferred from the Department of Neurosurgery where he was undergoing investigation of a brain tumor, to the Department of Medicine for investigation of gastrointestinal symptoms. The patient was diagnosed as having Turcot syndrome, and was then transferred to the Department of Surgery for treatment of an obstruction in the sigmoid colon and small intestinal invagination. A subtotal colectomy with side-to-end ileoproctostomy and release of the invaginations was carried out. Multiple polyps were found in the colon, two of which, including a large polyp that obstructed the colonic lumen, were confirmed histologically to be adenocarcinoma. The remaining polyps were adenomas. A biopsy of the brain tumor confirmed a diagnosis of astrocytoma (WHO grade II). This case report describes the characteristic features of Turcot syndrome presented by this patient.

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

Typical Turcot's syndrome is characterized by the association of a brain glioma together with multiple colonic polyposis, in which the number of polypoid lesions is small and the association of colonic cancer occurs at a younger age than in familial adenomatous polyposis. We describe a family in which both the father and his son presented with typical Turcot's syndrome without parental consanguinity. This is the first report of a family that is considered to follow an autosomal dominant inheritance. After reviewing 25 documented cases in which the average age of death was 20.3 years old, it was learned that the major cause of death was brain tumor (76 percent) and the minor cause was colon cancer (16 percent). Patients were very young and, therefore, unlikely to have produced a child before their death. These facts seem to support the theory that Turcot's syndrome is an autosomal dominant disorder.

Genetic alterations in a patient with Turcot's syndrome

Turcot's syndrome (TS) is a rare disorder associated with the development of both brain and colon neoplasms. Because of the very low incidence of the disease, its molecular basis remains unclear. Presented is a TS case of a 30-year-old Japanese male with a histopathologically confirmed diagnosis of both brain tumor (glioblastoma multiforme) and colon tumor (well-differentiated adenocarcinoma). Germline mutations of the p53 gene, somatic mutations of the Ki-ras, p53 and APC genes, and microsatellite instability (MSI) was examined using polymerase chain reaction (PCR)-single strand conformation polymorphism analysis, followed by PCR-direct sequencing, and sequencing after subcloning. No germline mutations of the p53 gene were found. Somatic mutations of Ki-ras and APC genes were found in the colon adenocarcinoma but not in the brain tumor. No somatic mutation of the p53 gene was present in either colon or brain tumors. Microsatellite instability of both colon and brain tumors was positive in two of four loci. These results indicate that the colon tumor of the TS patient carries the Ki-ras and APC gene mutations. The finding of MSI in both the brain and the colon tumors may support the hypothesis that alterations of DNA repair genes are involved in the tumor development of the TS patient.

The molecular basis of Turcot's syndrome

BACKGROUND

Turcot's syndrome is characterized clinically by the concurrence of a primary brain tumor and multiple colorectal adenomas. We attempted to define the syndrome at the molecular level.

METHODS

Fourteen families with Turcot's syndrome identified in two registries and the family originally described by Turcot and colleagues were studied. Germ-line mutations in the adenomatous polyposis coli (APC) gene characteristic of familial adenomatous polyposis were evaluated, as well as DNA replication errors and germline mutations in nucleotide mismatch-repair genes characteristic of hereditary nonpolyposis colorectal cancer. In addition, a formal risk analysis for brain tumors in familial adenomatous polyposis was performed with a registry data base.

RESULTS

Genetic abnormalities were identified in 13 of the 14 registry families. Germ-line APC mutations were detected in 10. The predominant brain tumor in these 10 families was medulloblastoma (11 of 14 patients, or 79 percent), and the relative risk of cerebellar medulloblastoma in patients with familial adenomatous polyposis was 92 times that in the general population (95 percent confidence interval, 29 to 269; P < 0.001). In contrast, the type of brain tumor in the other four families was glioblastoma multiforme. The glioblastomas and colorectal tumors in three of these families and in the original family studied by Turcot had replication errors characteristic of hereditary nonpolyposis colorectal cancer. In addition, germ-line mutations in the mismatch-repair genes hMLH1 or hPMS2 were found in two families.

CONCLUSIONS

The association between brain tumors and multiple colorectal adenomas can result from two distinct types of germ-line defects: mutation of the APC gene or mutation of a mismatch-repair gene. Molecular diagnosis may contribute to the appropriate care of affected patients.

Turcot's syndrome: a new case in the first decade of life

A case of Turcot's syndrome is described in an 8-year-old girl. Turcot's syndrome is a rare hereditary disease in which malignant glioma of the central nervous system is associated with colonic polyposis. The patient initially presented with a left parietal glioblastoma diagnosed by computed tomography (CT), and was subsequently found to have nonfamilial colonic polyposis.

Turcot's syndrome: case report and review of the classification

We report a case of association of a brain tumor with multiple colorectal polyposis and offer an analysis of the relevant literature with a view to revising the classification of the syndrome in relation to familial multiple polyposis and Gardner's syndrome. Differences emerged, depending on the brain tumor type, which suggests that this association may be classified as two distinct syndromes.

Germ-line and somatic mutations of the APC gene in patients with Turcot syndrome and analysis of APC mutations in brain tumors

The Turcot syndrome (TS) is a rare, probably autosomal recessive, disorder characterized by development of primary neuroepithelial tumors of the central nervous system (CNS) and numerous adenomatous colorectal polyps. To examine the possible involvement of mutations of the APC gene, which is responsible for familial adenomatous polyposis (FAP), in Turcot syndrome, we examined DNAs from TS patients for alterations in this gene by means of ribonuclease protection analysis. Germ-line APC mutations were detected in each of three unrelated cases of TS, and additional (somatic) mutations were observed in colonic adenomas that had developed in one of these patients. However, no somatic mutations in APC were found among 91 neuroepithelial tumors (medulloblastoma, glioblastoma, astrocytoma, and oligodendroglioma), whether sporadic or associated with TS. These results suggest that the APC gene is associated with pathogenesis of one feature of TS, but that at least one other gene is responsible for the genesis of neuroepithelial tumors in the CNS.

Genetics of primary brain tumors: a review

In this review we provide evidence for the existence of genes associated with primary malignant brain tumors. We summarize the current knowledge from studies of familial cancer aggregation, hereditary syndromes, and molecular and cytogenetic studies. The epidemiologic evidence is suggestive but inconclusive for an association between brain tumors and cancers in other family members, including cancers of the breast, lung and colon. Central nervous system (CNS) tumors have been associated with several hereditary syndromes including the Li-Fraumeni cancer family syndrome, neurofibromatosis (types 1 and 2), tuberous sclerosis, nevoid basal cell carcinoma syndrome, familial polyposis, and von Hippel-Lindau disease. Significant studies leading to the recognition of molecular and cytogenetic abnormalities in malignant gliomas are described in detail. The genetic studies conducted thus far suggest a role for inherited susceptibility in some CNS tumors.

Molecular alterations in a patient with Turcot's syndrome

Cells of a patient with Turcot's syndrome and of her parents were evaluated for the presence of molecular alterations in the p53 and the Ki-ras gene. Deletions on chromosome 17p, overexpression and point mutations of the p53 gene as well as mutations of the Ki-ras gene were detected in primary and metastatic tumour but not in the germline of the patient nor in her parents.

Turcot's syndrome and familial adenomatous polyposis associated with brain tumor: review of related literature

We investigated clinical manifestations in 124 patients with a possible Turcot's syndrome whose data were taken from documented cases. The cases were subclassified mainly on the bases of the type of familial occurrence and listed in five Tables. We searched for differences in colonic manifestation, histologic type of glioma, mode of inheritance, frequency of parental consanguinity, skin lesions and other accompanying lesions among these five groups. The differences of these clinical findings suggested that glioma-polyposis syndrome should be classified as follows; (1) cases of Turcot's syndrome who had characteristic colonic and brain manifestations, (2) cases of FAP associated with glioma, (3) suspicious cases of glioma-polyposis, and (4) cases other than glioma-polyposis syndrome.

The Turcot syndrome (glioma polyposis) and its neurosurgical significance. Case report

We report on a 12-year-old patient with Turcot Syndrome (Glioma polyposis). This patient's case deals with the association between a glioblastoma, anaplastic glioma (WHO Grade III) and colonic adenocarcinoma based on familial polyposis coli. Possible etiology and neurosurgical, clinically important characteristics of this rare syndrome, such as the young age of the patient and the relatively long survival time, will be discussed.

Genetic evidence that Turcot syndrome is not allelic to familial adenomatous polyposis

Turcot syndrome (TS) is a rare genetic disease in which brain tumors occur in association with colonic polyposis. Since Turcot's original description in 1959, there have been disagreements about the mode of inheritance as well as the clinical expression of this condition. Some investigators maintain that TS is a phenotypic variant of the autosomal dominant familial adenomatous polyposis (FAP), while others observe that there are clinical differences between TS and FAP, and that the pattern of inheritance of TS is autosomal recessive. The distribution of persons with colonic lesions in a family with a patient of colonic polyposis and a brain tumor, described in this report, favored the recessive hypothesis. In this family, the involvement of the FAP gene on chromosome 5q21-q22 could be excluded by a linkage study using a panel of FAP-linked DNA markers. This finding, which indicates the occurrence of another polyposis gene elsewhere in the genome, will have consequences for the presymptomatic diagnosis of FAP by linked DNA markers. We conclude that TS is a distinct clinical-genetical entity with the triad of atypical polyposis coli, CNS tumors, and a recessive mode of inheritance.

Turcot's syndrome

A non-familial case of cerebellar medulloblastoma associated with adenomatous polyposis coli is described and the literature is reviewed. This is the second reported case of Turcot's syndrome in Australia. A greater understanding of the genetic implications of this rare condition might be achieved through reporting of cases and long-term documentation with polyposis registries.

Turcot's syndrome. Flow cytometric analysis

Turcot's syndrome is a rare, genetically transmittable disease in which patients with colonic polyposis (possibly complicated by the progression to adenocarcinoma) have malignant central nervous system neoplasms. Dominant, recessive, and sporadic cases have been described. A 26-year-old man is reported with no relevant family history who had intermittent abdominal discomfort in 1986. Sigmoidoscopy revealed numerous polyps, several of which showed carcinomatous change. Dukes' Stage C colorectal carcinoma was diagnosed. Treatment consisted of total colectomy with construction of a Koch's pouch. He remained well for 3 years until onset of headache, nausea, and vomiting. Computed tomographic scan disclosed a large, circumscribed, enhancing, right frontoparietal mass. After craniotomy and partial resection, histologic review disclosed anaplastic astrocytoma. He received cranial radiation therapy, 6000 cGy, by parallel opposed ports to the tumor bed, and carmustine 200 mg/m2 intravenously every 8 weeks. Flow cytometric DNA analysis was done on the paraffin-embedded archival material from the patient's normal colon, colonic adenocarcinoma, and anaplastic astrocytoma. DNA histograms revealed diploid distributions in all three samples. The G2/M fraction of the astrocytoma was elevated at 16%, and the S-phase fraction of the colonic adenocarcinoma was 19.4%.

Genetic epidemiology of childhood brain tumors

The study goal was to determine the genetic (heritable) contribution to childhood brain tumors (CBT) which cause nearly one quarter of all childhood cancer deaths. Their etiology remains unknown, but previous studies have suggested a proportion of CBT may be heritable. In this study we collected family histories of 243 confirmed CBT patients referred to The University of Texas M. D. Anderson Cancer Center between the years 1944 and 1983, diagnosed before age 15, and residents of the United States or Canada. Family histories were obtained for all the probands' first degree relatives (parents, siblings, and offspring) and extended to include selected second degree relatives (aunts, uncles, grandparents) using sequential sampling. To determine if these CBT families exhibited excess cancer, we compared their cancer experience to age-, race-, sex-, and calendar-year specific rates from the Connecticut Tumor Registry. No cancer excess was observed among 1,099 first and second degree relatives [39 cancers observed (O) and 44 expected (E) for a standardized incidence ratio (SIR) of 0.88]. For colon cancer, although small numbers, five cases were observed among the probands' first degree relatives with 1.6 expected, for a significant SIR of 3.10. Segregation analysis demonstrated that chance alone could not account for the observed cancer distribution with a multifactorial model providing the best overall explanation of the data. Overall, heredity played a role in the etiology of CBT in 4% of the study families: four (1.7%) due to known hereditary syndromes (nevoid basal cell carcinoma syndrome and von Recklinghausens neurofibromatosis--NF-1), four (1.7%) with multifactorial inheritance, and two additional families with cancers aggregating similar to the clinical criteria described for the Li-Fraumeni cancer family syndrome.

Turcot's syndrome with intestinal lymphoma in a child: an unusual case of triple tumor

Turcot's syndrome, the association of brain tumor (usually glioblastoma, medullo-blastoma, or astrocytoma) and colonic polyps, is a very rare condition of which about 20 cases have been reported. It has been described only once previously with cancer in a third organ system. In this paper, we report a child affected with colonic polyposis and astrocytoma (i.e., Turcot's syndrome) associated with intestinal non-Hodgkin's lymphoma.

Turcot's syndrome: a diagnostic consideration in a child with primary adenocarcinoma of the colon

We report the diagnosis of an adenocarcinoma of the colon in a 12-year-old girl in association with the presence of a small number of adenomatous polyps and a positive family history of a sibling with a central nervous system glioma. These findings implicate Turcot's syndrome as the cause for the development of intestinal and intracranial neoplasms in the two siblings. Since primary adenocarcinoma of the bowel is unusual in children, an underlying predisposing condition should be sought in affected cases.

Brain tumors in familial adenomatous polyposis

Familial adenomatous polyposis was always believed to be a colonic disease of genetic determination with a high risk of development of cancer of the large bowel. Over the years the list of extracolonic manifestations of this disease, both benign and malignant, has amplified. Brain tumors and, in particular, medulloblastoma have not become recognized as major malignant extracolonic manifestations of familial adenomatous polyposis. They are of particular significance because, unlike most of the other manifestations, they occur prior to or early in the development of the colonic manifestations of this disease. This report documents the investigation of 168 kindreds in The Cleveland Clinic Familial Adenomatous Polyposis Registry in a search for those at-risk individuals who developed brain tumors.

Turcot's syndrome. A review

Turcot's syndrome represents the association between familial multiple polyposis coli and neural tumors. The syndrome is reviewed with reference to genetics, colonic and central nervous system manifestations. This evidence suggests that Turcot's syndrome represents one manifestation of the pleiotropic autosomal dominant gene responsible for familial polyposis coli and the associated extracolonic manifestations of Gardner's syndrome. A diagnosis of Turcot's syndrome should be restricted to those patients with familial polyposis coli associated with gliomas or medulloblastomas. A further case is presented that is believed to be the first report of such a case in the United Kingdom.

Nonfamilial intestinal polyposis and brain tumor in a 5-year-old girl

A 5-year-old girl with glioblastoma multiforme and simultaneous adenocarcinoma in one of multiple colonic polyps is the youngest reported case of Turcot's syndrome. A literature survey and a classification based on family pedigree and pattern of inheritance are proposed.

Turcot's syndrome

The first reported case of Turcot's syndrome (brain tumour with polyposis coli) in Australia is described. An awareness of the possible extracolonic concomitant conditions of polyposis coli should lead to the prompt investigation of any patient with either known polyposis or a family history of polyposis who develops a disorder of the central nervous system.

Turcot syndrome and its characteristic colonic manifestations

The reported clinical manifestations of Turcot syndrome were studied to determine whether these corresponded to those of Turcot's original cases. Among the patients with well-documented colonic lesions, the colonic lesions were classified into three groups. First, there was a main group in which colonic lesions had the following characteristics that coincided with those of Turcot's original cases: a low number of polyps (20-100), large polyps over 3 cm in diameter, and complication by colonic cancer during the second or third decades. In the second group, the patients had too few polyps to be diagnosed as polyposis. The third group included patients with numerous colonic polyps similar to those of familial polyposis coli. The recognition of these characteristics of colonic lesions may lead to early detection of glioma in the asymptomatic period.