FAP : Clinical Features
Clinical Features of Familial Adenomatous Polyposis (FAP): In classic FAP, the patients develop hundreds to thousands of adenomatous polyps in the colon, usually starting at 10 to 12 years of age. The average age for the diagnosis of adenomas is 36 years, for cancer 39 years, and death from cancer, 42 years. The presenting symptoms are often non-specific such as hematochezia, diarrhea, and abdominal pain. Upper Gastrointestinal Tract Lesions in FAP: Patients with FAP can develop fundic gland polyps of stomach (more common) and gastric adenomas (rare). Epithelial dysplasia is present in 25% to 40% of cases. Adenomas of small bowel, especially around periampullary region, commonly develop in FAP patients. Extraintestinal Manifestations in FAP: In addition to gastrointestinal polyposis, the patients with FAP or one of its variants can show bone abnormalities (osteomas of mandible, skull, and long bones; exostoses; dental abnormalities; mandibular cysts), desmoid tumors (Gardner syndrome), congenital hypertrophy of retinal pigment epithelium, epidermoid cysts, fibromas, and tumors of adrenal and thyroid gland.