[Intraabdominal desmoid tumors in familial adenomatous polyposis]

Genetic characteristics and extracolonic phenotypic manifestations in patients with familiar adenomatous polyposis

INTRODUCTION

Familial adenomatous polyposis (FAP) is a hereditary disease caused by mutations in the APC gene, which is also associated with extracolonic manifestations. The objective was to characterize the extracolonic manifestations in a cohort of patients with classic FAP and the possible genotype-phenotype association.

MATERIALS AND METHODS

The study design was observational and descriptive. Demographic, clinical, and genetic variables were collected based on the type of mutation (frameshift, nonsense, splicing, rearrangement, and others).

RESULTS

We included 45 patients with FAP (mean age 47years, range 21-78; 51% female), belonging to 21 families, with a median of 2 (range 0-6) manifestations per patient. Eighty percent (n=36) had upper digestive tract involvement, with duodenal adenomas (73%), fundic gland polyposis (56%), and ampullary adenoma (36%) being the most frequent findings. The most common extraintestinal manifestations were desmoid tumors (16%) and papillary thyroid carcinoma (13%). Thirty eight percent of the patients presented an aggressive phenotype (SpigelmanIII-IV, high-grade dysplasia, invasive neoplasia, desmoid tumor, and papillary thyroid carcinoma). The most common genetic mutations were frameshift (56%), nonsense (26%), and splicing (16%), primarily located in exon15 (50%). No significant correlation was found between the type of genetic mutation and the severity or location of phenotypic manifestations.

CONCLUSIONS

One-third of patients with FAP present an aggressive phenotype, without a demonstrated correlation between the type of genetic alteration and the phenotypic manifestations.

Transverse colonic volvulus due to mesenteric fibromatosis: a case report

BACKGROUND

Colonic volvulus, a condition in which a colonic segment partially twists around its base, is the third leading cause of large bowel obstruction after colonic neoplasms and diverticular disease. However, volvulus of the transverse colon is the rarest type of large intestinal volvulus. Moreover, the occurrence of transverse colonic volvulus secondary to a benign tumor originating from outside the intestine has never been reported. We hereby report a case of transverse colonic volvulus caused by mesenteric fibromatosis.

CASE PRESENTATION

A 53-year-old female with a history of rheumatoid arthritis and thyroid tumor presented with abdominal pain for 1 day. Abdominal computed tomography revealed intestinal torsion at the hepatic flexure. Twisted and obstructed mucosa of the transverse colon was observed during colonoscopy, but no tumor invasion of the mucosal surface was detected. A solid mass of a mesenteric origin with involvement of the transverse colon was observed during surgery. The mass was diagnosed surgically as transverse colonic volvulus induced by a mesenteric tumor. Hence, the patient underwent a right hemicolectomy. Histopathological results indicated mesenteric desmoid-type fibromatosis. The postoperative recovery was uneventful, and the patient was discharged 8 days after surgery.

CONCLUSIONS

Although mesenteric fibromatosis is rare, this disease should be considered when managing transverse colonic volvulus resulting from nonmucosal tumors.

Desmoid-type Fibromatosis of the Splenic Hilum: A Rare Tumor at an Unusual Location

Desmoid-type fibromatoses (DTFs), also known as desmoid tumors, are benign but infiltrative neoplasms that often appear next to previous surgical site. Intra-abdominal tumors usually involve the mesentery, but splenic hilum is an unusual localization. We present a case of a desmoid tumor of the splenic hilum laparoscopically resected in a 70-year-old male with a previous history of chromophobe renal cell carcinoma and ocular spindle melanoma. Although benign, desmoid tumors might be infiltrative and produce serious complications. Treatment remains controversial, ranging from surgery and medical therapies to observation. Management of DTF must be individualized, considering the risk of complications and recurrence.

Mesenteric fibromatosis misdiagnosed with lymph node metastasis after successful laparoscopic right hemicolectomy: a report of two cases with review of literature

Fibromatosis is a rare type of tumor derived from the mesenchymal tissue. This is a benign tumor with infiltrating growth but may invade locally and recur following excision. As one type of fibromatosis, mesenteric fibromatosis (MF) accounts for a mere 8% of cases. Although studies have revealed that the etiology of MF is related to trauma, surgery, hormones, and heredity, the specific etiology of fibromatosis remains unclear. With such low incidence, MF has been rarely reported and tends to be misdiagnosed due to insufficient recognition. In this paper, we describe the cases of two patients with MF who were misdiagnosed with lymph node metastasis and who had previously undergone successful laparoscopic right hemicolectomy. We provide this information in order to broaden the clinical understanding of MF.