Familial adenomatous polyposis in association with thyroiditis. Report of two cases

Prevalence of thyroid diseases in familial adenomatous polyposis: a systematic review and meta-analysis

Thyroid cancer (TC) is a known extra-intestinal manifestation and contributes to the mortality and morbidity in patients with familial adenomatous polyposis (FAP). Its exact prevalence is not well established and recent studies have shown an increasing number of TC in this patient population. The prevalence of benign thyroid masses and endocrinologic thyroid disorders are also poorly described. We conducted a systematic review and meta-analysis by using a random-effects model to characterize TC and estimated the prevalence of thyroid diseases in FAP patients. Twelve studies (n = 9821) were included. Pooled prevalence of TC, benign thyroid masses, and endocrinologic thyroid disorders in FAP were 2.6% [95% confidence interval (CI) 1.3-4.8], 48.8% [95% CI 33.8-64.0], and 6.9% [95% CI 4.5-10.3] respectively. Subgroup analyses revealed higher prevalence of TC in studies with fewer participants, studies that used screening ultrasound to diagnose TC, and studies that were published after 2002. TC diagnosis preceded the diagnosis of FAP in 34% of the patients. The means age at diagnosis of FAP and TC were 29 and 31 years, respectively. 95% of the patients were female and the most common pathology was of papillary subtype (83.3%). Most mutations (79.2%) were located at the 5' end of APC gene. In summary, benign thyroid disorders are common in FAP, yet, TC is an uncommon phenomenon. Certain patient subset, such as young female with APC mutation at the 5' end, might benefit from routine surveillance ultrasound.

Results of a prospective thyroid ultrasound screening program in adenomatous polyposis patients

BACKGROUND

Patients with adenomatous polyposis may be at increased risk for developing thyroid cancer (TC). However, screening guidelines for TC in these patients are not well established.

METHODS

Patients with a diagnosis of familial adenomatous polyposis, attenuated familial adenomatous polyposis, and gene mutation-negative adenomatous polyposis enrolled in our Hereditary Colorectal Cancer Family Registry were eligible for a screening thyroid ultrasound (US). Findings were reviewed by the study endocrinologist and intervention and/or follow-up determined.

RESULTS

Fifty patients underwent screening thyroid US. Thirty-four (68%) patients had abnormal findings on US, including 27 (79%) with thyroid nodules. In 7 patients, US-detected thyroid nodules met established criteria for fine-needle aspiration. Of the 6 patients who underwent fine-needle aspiration, 2 (4%) were diagnosed with papillary TC. Both of these patients were female.

CONCLUSIONS

A large proportion of adenomatous polyposis patients will have abnormal results on thyroid US, including suspicious-appearing thyroid nodules that when biopsied are malignant. Female patients have an apparently greater risk of developing TC. Polyposis patients, especially women, should be offered participation in a thyroid US screening program.

Thyroid cancer in Gardner's syndrome: Case report and review of literature

Gardner’s syndrome is a variant of familial adenomatous polyposis. A multitude of extra-colonic manifestations including various endocrine tumors have been associated with this syndrome, the commonest of which is thyroid cancer. Majority of the patients with thyroid cancer and Gardner’s syndrome are females. Here we describe a male patient with Gardner’s syndrome who subsequently developed thyroid cancer.

Lymphocytic infiltration in pediatric thyroid carcinomas

Lymphocytic thyroiditis has been associated with an increase in the incidence of thyroid papillary carcinoma in some reports, mostly series of both adults and children. Relatively little is written about thyroiditis and follicular carcinomas. We have seen several cases of pediatric follicular thyroid carcinomas, that had an associated lymphocytic infiltrate, which led us to examine all primary malignant thyroid neoplasms in our surgical files from 1984 through 2000 to examine this relationship. We also investigated the nature of the lymphocytic infiltrate with routine immunohistochemistry. Ten patients (five male, five female, ages 4.5-21 years of age) had a thyroid carcinoma resection, six (three males and three females) with papillary carcinoma and four patients (two males and two females) with low-grade follicular carcinoma. Seven samples (one male had two cases with tumor) from patients who had a papillary carcinoma resection with tissue blocks available were identified (one patient had slides but no blocks), as were all four patients with a follicular carcinoma. The thyroid of all patients with a follicular carcinoma contained a lymphocytic infiltrate; only four of the seven papillary carcinoma samples had an associated lymphoid infiltrate. In all cases with a lymphoid infiltrate, the infiltrate was present in both lobes (both adjacent and separate from the tumor). B lymphocytes were present in the lymphoid infiltrate of three of four patients with follicular carcinomas and in 1 of 3 cases of papillary carcinomas. T cells were dispersed throughout all the tumors with lymphoid infiltrates. We conclude that pediatric follicular carcinomas have an associated lymphocytic infiltrate in the tumor and/or adjacent thyroid, more commonly than papillary carcinomas.

Familial adenomatous polyposis associated thyroid carcinoma: a distinct type of follicular cell neoplasm

Thyroid carcinoma has been described as occurring more frequently than expected in association with familial adenomatous polyposis. The histology of these cases has not been described in detail, although the reported cases were usually diagnosed as papillary carcinoma. We now report the pathological features of four cases of thyroid carcinoma associated with familial adenomatous polyposis, and review the findings in the literature. The tumours in these four cases were all of follicular cell origin as shown by thyroglobulin immunohistochemistry. In three they were multifocal. The tumours showed some features of papillary carcinoma--grooved nuclei and papillary architecture, but these were not consistent. They also showed features that were unusual for papillary carcinoma--a cribriform pattern and solid areas with spindle cell component. Commonly the tumours combined both patterns. A review of the reported cases of thyroid cancer associated with familial adenomatous polyposis showed that they also were commonly multifocal and occurred predominantly in young women. When the histology was adequately reported or illustrated it was, in most instances, consistent with the findings in our own cases. We therefore suggest that these thyroid tumours form a distinct type with some unusual features. Clearly it is likely that the APC gene is associated with their pathogenesis, and that other factors contribute to the predominantly female incidence in this as in sporadic tumours. Six of 63 reported cases showed metastasis or died from thyroid carcinoma. In a number of cases the tumours presented before the familial adenomatous polyposis was recognized. The findings of these unusual histological features in a thyroid tumour, and particularly of multicentricity, should alert the pathologist to the possibility of familial adenomatous polyposis with its implications for family screening. The tumours are often well demarcated but, because of the multicentricity, total thyroidectomy should be advocated.

Analysis of adenomatous polyposis coli gene in thyroid tumours

Familial adenomatous polyposis (FAP) is known to be associated with neoplasia of various tissues, including thyroid carcinoma. Germline mutations of the tumour-suppressor gene APC, responsible for the predisposition to FAP, may therefore be involved in the pathogenesis of these tumours. In this report the structure of the APC gene has been investigated in 26 thyroid tumours, at different stages of dedifferentiation, that were surgically excised from patients with a negative history of FAP. Approximately 35% of the APC gene coding region, where most of the mutations are clustered, has been analysed by a combination of single-strand conformation polymorphism and direct sequencing. No significant alterations could be demonstrated in any sample examined. It is concluded that, at least in patients not affected by FAP, APC gene abnormalities do not seem to play a relevant role in the pathogenesis of thyroid carcinoma.

Increased risk of thyroid and pancreatic carcinoma in familial adenomatous polyposis

Familial adenomatous polyposis has been associated with several extraintestinal cancers, but the relative and absolute risks of these malignancies have not been determined. Extraintestinal cancers reportedly associated with adenomatous polyposis (thyroid gland, adrenal gland, pancreas, and biliary tract) were identified in polyposis patients and their at risk relatives in The Johns Hopkins Registry. The incidence rates of identified tumours were then compared with the general population through person year analysis with adjustment for population. For comparison, the incidence rates of the two most common cancers not associated with polyposis (breast cancer in women and lung cancer) were also calculated. There was an increased relative risk of thyroid cancer (relative risk 7.6; 95% confidence limits (CL) 2.5-17.7) and pancreatic adenocarcinoma (relative risk 4.46; 95% CL 1.2-11.4) in polyposis patients and at risk relatives. The absolute risk was 26.8 and 21.4 cases/100,000 person years, respectively. No cases of adrenal or biliary cancer were found in this cohort. There was no increased relative risk of lung cancer (95% CL 0.04-1.4) or breast cancer (95% CL 0.04-1.4) over the general population. The relative risks of thyroid and pancreatic cancer are increased in familial adenomatous polyposis, but the absolute lifetime risk is low. Screening for pancreatic cancer may not be worthwhile with currently available methods, but careful physical examination of the thyroid gland is warranted along with consideration for ultrasonography.

Evaluation of molecular genetic diagnosis in the management of familial adenomatous polyposis coli: a population based study

A population based clinical and molecular genetic study of familial adenomatous polyposis coli (FAPC) was performed to investigate the value of molecular genetic analysis and ophthalmological assessment in the presymptomatic diagnosis of FAPC. The point prevalence of affected patients was 2.62 x 10(-5) (1/38,000) and the minimum heterozygote prevalence was estimated at 3.8 x 10(-5) (1/26,000). Eight of 33 (24%) probands were new mutations. Forty-eight asymptomatic relatives at 50% prior risk aged between 10 and 40 years were assessed for risk modification with linked DNA markers: in nine subjects (18%) the family structure was unsuitable for linkage based analysis, but 32 subjects were informative with a panel of intragenic and closely linked markers (25 had a combined age/DNA related risk of < 1% (low risk group) and seven were at high risk (DNA predicted risk > 99%)). Ophthalmological assessment for CHRPEs showed that 27/43 (63%) affected patients and high risk relatives and 0/18 low risk relatives had more than three CHRPEs. Interfamilial variation in CHRPE expression was apparent. This study has shown that DNA based risk modification with intragenic and closely linked DNA markers is informative in most FAPC families. In addition to the clinical benefits of presymptomatic diagnosis for FAPC, the reduction in screening for low risk relatives (365 person years in the present study) means that molecular genetic diagnosis of FAPC is a cost effective procedure.

Familial adenomatous polyposis (Gardner's syndrome) and thyroid carcinoma. A case report and review of the literature

The case history of a 24-year-old woman with Gardner's syndrome [familial adenomatous polyposis (FAP)] and papillary thyroid carcinoma is presented, representing the 37th report of this association. Although FAP is transmitted as an autosomal dominant trait with similar penetrance in both sexes, thyroid carcinoma has been found almost exclusively in women (94.3%). The majority have been papillary carcinomas (88.5%), which have become apparent during the third decade (average 23.6, range 16-40 years). Most (55.5%) thyroid carcinomas have been discovered 1-17 years after FAP was identified, although some have been found before (29.6%), or at the same time (14.8%) FAP was diagnosed. Multicentric papillary carcinomas have been reported in 64% (14 of 22) of FAP patients, a frequency at least twofold greater than usual. Although papillary carcinoma found before age 30 (as it was in most patients with FAP) typically has an excellent prognosis, one patient with FAP developed distant metastases from thyroid carcinoma and a 28-year-old woman's death was attributed to papillary carcinoma. The high frequency of multicentric papillary thyroid carcinoma in young patients with FAP and the potential for metastases and death due to thyroid carcinoma warrant aggressive diagnostic screening at regular intervals with neck palpation, ultrasonography, and if necessary, fine-needle aspiration biopsy. When thyroid carcinoma is found, total or near-total thyroidectomy should be considered because of the tumor's high likelihood of being multifocal.(ABSTRACT TRUNCATED AT 250 WORDS)

Bannayan-Riley-Ruvalcaba syndrome

Here we report on 12 affected members of a family with Bannayan-Riley-Ruvalcaba syndrome. We present clinical evidence of overlap between Bannayan-Zonana syndrome. Riley-Smith syndrome, and Ruvalcaba-Myhre syndrome in this autosomal dominantly inherited condition. We expand the phenotypic spectrum to include Hashimoto thyroiditis, which occurred in 7 of our cases. Finally, we discuss the relationship between the syndrome and juvenile polyposis of infancy.