Variant of familial adenomatous polyposis (FAP)
characterized by benign growths of fibrous tissue (hyperproliferation of
epithelial mesenchymal tissues) that form either spontaneously or after
surgery. These tumors can become large and aggressive, compressing abdominal
Aggressive Fibromatosis; Familial Infiltrative
Up to 13% of patients with FAP have associated
desmoid disease (FAP affects 1:8000 individuals). The incidence of HDD
occurring alone remains to be determined.
Autosomal dominant with 100% penetrance.
The majority of mutations affect the adenomatous polyposis coli (APC) gene
(a tumor suppressor) on chromosome 5 distal to the beta-catenin-binding
domain (5q15-22). New mutations account for 20 to 30% of families affected with this condition (direct
mutation testing is required to establish diagnosis).
The APC gene is a tumor suppressor. The APC protein
seems to act like a cell-signaling protein. Mutations in the APC gene are
responsible for generating slowly growing fibrous masses consisting of
bundles of spindle cells with variable amounts of collagen. Hereditary
desmoid disease occurs with or without colonic polyposis and consists of
infiltrative fibromatosis of connective tissues invading multiple parts of
the body. Desmoid tumors may also present as extracolonic manifestations in
some patients with FAP.
Based on clinical aspect, familial history, genetic
studies, and tissue biopsy.
HDD patients develop multifocal fibromatosis:
arms, breast, paraspinal muscles, occiput, lower ribs, abdominal wall, and
mesentery. Desmoid tumors may proliferate in various areas: arms, ribs,
breasts, occiput, mesentery, abdominal wall, and paraspinal muscles.
Epidermal cysts and osteomata of the skull and mandible, as well as
scoliosis caused by desmoid disease, have been described. Desmoid tumors are
not considered malignant per se, but their local aggressiveness and
recurrence after surgical removal are frequent. Although some families with
HDD are predisposed to colonic carcinoma, colonic polyposis is rare. Up to
90% of FAP patients have congenital hypertrophy of the retinal pigment
epithelium (<40% of control patients).
Inquire about associated familial
colonic polyposis (anemia). Inquire about the location of the lesions to be
excised (some locally invasive desmoid tumors may be close to major blood
vessels). Obtain hemoglobin level and blood cell count.
Careful positioning and padding are
required to avoid trauma to superficial lesions. Although very rare,
mandibular osteomata have not been known to make tracheal intubation
difficult. Should mandibular lesions become such that they interfere with
laryngoscopy, fiberoptic intubation should be considered by either oral or
nasal route. Depending on the location and degree of invasion of the tumor,
significant blood loss is possible.
No known specific implications with
Other mutations within the APC
gene, including the following:
Familial Adenomatous Polyposis (FAP): Most severe autosomal
dominant variant of mutation in the APC gene (tumor suppressor gene). FAP is
characterized clinically by the development of a considerable number of
adenomatous polyps within the colon that become cancerous if they are not