What is Gardner syndrome?

Updated: Jun 06, 2020
  • Author: Jaime Shalkow, MD, FACS; Chief Editor: Cameron K Tebbi, MD  more...
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Answer

In 1962, Gardner and colleagues noticed extra-colonic manifestations in some kindred with polyposis. In this syndrome, the polyps are adenomatous rather than hamartomas. [21]

The associated extraintestinal tumors include desmoid cysts, cysts of the mandible, fibromas, osteomas, and hypertrophy of the retinal pigmented epithelium. [21]  Bone tumors are most common (80%), followed by inclusion cysts (35%) and desmoid tumors (18%). [12] The syndrome is inherited in an autosomal dominant pattern. Osteomas are most frequently found in the skull and facial bones. Abnormal dentition is common. [10] Periampullary malignancies may develop during the third or fourth decades of life at rates much higher than in the general population. [12]

Gardner syndrome is considered a phenotypic variant of FAP, and different mutations on the adenomatous polyposis coli (APC) gene have been shown to be associated with this syndrome (APC polymorphism in exons 13 and 15). [22] Intestinal polyps have a 100% likelihood of undergoing malignant transformation. [23]

The natural history and treatment of patients with colonic polyps are the same as in those with FAP. Desmoid tumors of the abdominal wall and mesentery occur in 20% of patients with Gardner syndrome, usually appear 6-30 months after surgery for intestinal manifestations, and are the leading cause of death in patients who have undergone colectomy. Desmoid tumors are dense fibroblastic proliferations but can present with dysplasia and even fibrosarcoma.

Treatment is challenging. When these tumors are small and well defined, excision is feasible with a recurrence rate of 10%; however, some are not identified until they become unresectable. Desmoids that involve the small bowel mesentery should be treated according to their symptoms and growth rate. Sulindac, tamoxifen, or vinblastine and methotrexate are adequate for slow-growing, mildly symptomatic tumors. Aggressive tumors require high-dose tamoxifen, or antisarcoma chemotherapy (doxorubicin and dacarbazine), and possibly radiation therapy. [24, 25]


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