|CASE IN POINT - CLINICS IN GASTROINTESTINAL SURGERY
|Year : 2016 | Volume
| Issue : 2 | Page : 118-120
Familial adenomatous polyposis: Associations, variants and more
Suvendu Maji, Makhan Lal Saha, Kamal Singh Kanwar
Department of General Surgery, Institute of Postgraduate Medical Education and Research, Kolkata, West Bengal, India
|Date of Web Publication||30-Dec-2016|
Department of General Surgery, Institute of Postgraduate Medical Education and Research, 244 AJC Bose Road, PG Hostel, Room No. 230, Kolkata - 700 020, West Bengal
Source of Support: None, Conflict of Interest: None
Familial adenomatous polyposis (FAP) is the most common adenomatous polyposis syndrome. It affects all age groups and all races. Almost all patients with FAP develop colorectal cancers in the absence of surgery. A number of variants of FAP have been described, out of which Gardner syndrome is one subtype. Indian data on FAP or its rarer variants is scarce and limited to isolated case reports due to its low incidence.  We herein report five cases of FAP treated in our hospital and illustrate challenges in the management. The case series also highlights the interesting case of the fifth female who presented with synchronous duodenal adenocarcinoma and colonic adenocarcinoma in the background of multiple polyps in the entire colon. The case amply highlights the need of increased awareness of the syndrome and its variants while treating patients with polyposis-related conditions along with a center of referral where facilities for screening, counseling, genetic tests, surgery, and tumor banking and multidisciplinary facilities are available.
Keywords: Familial adenomatous polyposis, Gardner syndrome, osteoma, polyps, proctocolectomy
|How to cite this article:|
Maji S, Saha ML, Kanwar KS. Familial adenomatous polyposis: Associations, variants and more. Astrocyte 2016;3:118-20
| Introduction|| |
Familial adenomatous polyposis (FAP) is a rare disease. The reported incidence of the disease ranges from 1 in 7000 to 1 in 22,000. The exact incidence of the disease in India is not known perhaps due to its rarity. It is an autosomal dominant disease with high penetrance. The affected individual develops hundreds of colorectal polyp typically at puberty, which are benign to begin with but turns malignant by the fourth or fifth decade of life. Although FAP accounts for <1% of all colorectal cancers, chance of developing colorectal cancer without appropriate intervention in the form of prophylactic surgery is nearly 100%. We here present five cases of FAP treated and managed successfully in our hospital during July 2012 to June 2014. The first three patients belong to the same family while the rest two are sporadic cases of FAP.
| Case Series|| |
Two sisters presented to us with similar complaints of prolonged bleeding per rectum while their younger brother was asymptomatic and screened for possible polyposis. The elder sister also complained of sensation of mass per rectum. Both of them also complained of occasional dull aching pain in abdomen and on and off passage of mucous per rectum. However, none of them reported loss of weight, anorexia, nausea, vomiting, hematemesis, or abdominal swelling or lump elsewhere in the body. Both of them were well nourished at presentation. The age range of presentation was 13-16 years. Physical examination was unremarkable except that both were moderately anemic. Perrectal examination revealed pedunculated polyps in the elder sister only while pervaginal examination was normal. There was no history of colorectal or gastrointestinal (GI) cancers in the family. However, there was a history of consanguinous marriage between their parents.
Based on clinical history, all of them underwent full-length colonoscopy and biopsy from suspected polyps. Upper GI endoscopy was normal in both the siblings. Colonoscopy revealed multiple polyps ranging from 1 to 2 cm in size carpeting the entire colon of both the sisters [Figure 1]a and b, while in case of their younger brother 3 polyps were found to be present. Based on biopsy, a diagnosis of juvenile polyposis was made in their younger brother and he has been planned for follow-up.
|Figure 1: (a and b) Colonoscopic view depicting multiple polyps carpeting the colon|
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The third female presented to us with the complaints of loose stool and bleeding per rectum for the last 6 months. She was cachectic and anemic on general survey. She did not have any family history of colonic polyposis or malignancy. Her biochemical parameters revealed low albumin and hemoglobin values. She was put on high rich protein diet for the same. On colonoscopy, she had multiple colonic polyps. Upper GI endoscopy was normal. Her surgery was delayed for a month due to poor nutritional status.
The fifth female presented to us with vague abdominal pain, loss of weight, and loose stool. She also had clinical jaundice. Her general survey also revealed the presence of multiple facial osteomas along with impacted teeth. Her family history revealed the presence of other first- and second-degree relatives with similar osteomas. She did not have any extra-abdominal desmoid or epidermal cyst. Based on the above findings, she was diagnosed to be a case of Gardner syndrome [Figure 2]. On upper GI endoscopy, she was found to have duodenal growth, biopsy of which was reported as duodenal adenocarcinoma. Her colonoscopy revealed the presence of numerous polyps of different sizes. Biopsy from them also revealed adenocarcinoma. She was planned for pancreaticoduodenectomy and proctocolectomy, but she denied such major operation and decided to be under close surveillance. A family screening for colonic polyposis was advised. However, her family members did not turn up for the same.
|Figure 2: Facial osteomas in the patient with Gardener syndrome (FAP variant)|
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All of the above patients (except the male child) underwent eye examination for retinal abnormalities. However, none had any significant ophthalmological finding. The two siblings from the same family and the third patient in the series underwent proctocolectomy with ileoanal pouch anastomosis and proximal ileostomy [Figure 3]. The fifth patient denied operation and the young child had been put under regular surveillance. Postoperatively, the first two patients developed diarrhea which was managed conservatively. The third patient developed minor wound infection and wound discharge which also subsided with antibiotics and wound dressing. Ileostomy closure was done in all the three of them after 8 weeks.
|Figure 3: Cut open section of a total proctocolectomy specimen demonstrating numerous polyps of different sizes|
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The patients are healthy on 8 months follow-up. The younger brother is under observation and on regular follow-up. The fifth patient, a female, was lost to follow up.
| Discussion|| |
FAP is a genetic disorder which accounts for 1% of colorectal cancer. ,, It is an autosomal dominant condition with 100% penetrance. Majority of the patients develop colorectal cancer unless detected early and managed by prophylactic removal of the colon and rectum. The underlying defect is a germline mutation in APC gene. A number of variants of FAP such as Turcot syndrome, attenuated adenomatous polyposis coli, MYH-associated polyposis, and Gardner syndrome have been described. Gardner syndrome occurs in 10% of patients with FAP. 
The frequency of FAP - Gardner syndrome is 1 in 12,000 live births to 1 in 4000 live births. Most patients with FAP are asymptomatic until they develop cancer. As a result, diagnosing presymptomatic patients is essential. Of patients with FAP, 75-80% have a family history of polyps and/or colorectal cancer at age 40 years or younger. Patients may develop extraintestinal manifestations such as congenital hypertrophy of retinal pigment epithelium, sebaceous cysts (51%), desmoids tumors (26%), and in lesser proportions, osteomas, lipomas, dental abnormalities (impacted or unerupted teeth, hypodontia, or compound odontomas) (Gardner syndrome), and extraintestinal malignancies; hepatomas, retinoblastomas, and brain tumors (Turcot syndrome). ,,,
The standard mode of diagnosis and screening is colonoscopy and biopsy of the suspected polyps. ,, The treatment of choice in FAP patients is restorative proctocolectomy with ileal pouch-anal anastomosis. The second most common malignancy (after colorectal carcinoma) in patients with FAP is adenocarcinoma of the duodenum and the papilla of Vater. It affects as many as 12% of patients. Hence, routine upper GI endoscopy in these patients is recommended.
The five cases described herein had all classical symptoms of FAP and were managed according to accepted guidelines. Interestingly, none of the five had any extracolonic manifestation of the disease. However, due to inavailability of genetic testing at our center and lack of counseling services, neither of them could be provided with the same. Furthermore, due to low general awareness of the syndrome among the common populations, other family members could not be convinced for screening and follow-up. Due to unavailability of tissue banking facilities, tissues could not be stored for further studies. The patient with a Gardner syndrome presented unique management challenges as synchronous duodenal adenocarcinoma and colorectal carcinoma in the setting of FAP has never been reported before. We failed to find out treatment protocol for the same even after extensive search of literature. Adequate management of such patients would require a combined team of surgeons, oncologist, dentist, geneticist, ophthalmologist, and a counselor. Better treatment outcomes can only be obtained through regionalization of all such cases to dedicated/higher centers. Hence, development of such centers and polyposis registries is suggested. Further, the series highlights the importance of early diagnosis to prevent development of florid cancers as was seen in the case of Gardner syndrome.
| Conclusion|| |
Early diagnosis of FAP is key to its successful management. Development of higher centers of referrals would help in better treatment outcome. Awareness in the general population and physicians can help in their prompt referral and diagnosis.
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[Figure 1], [Figure 2], [Figure 3]