Ruptured desmoid tumor imitating acute appendicitis – a rare reason for an emergency surgery

We report the case of a 27-year-old male patient presenting with the clinical picture of acute appendicitis. During the operation, we found a tumor in the jejunum with a necrotic zone and perforation on its surface, causing hemorrhagic effusion into the abdominal cavity and subsequent peritonitis. The tumor was removed with negative margins via resection of the small bowel. The final histological result showed aggressive fibromatosis. Aggressive fibromatosis remains a serious problem with the possibility of locally aggressive behavior with high rates of recurrence. Sometimes, its clinical and macroscopic recognition can be immensely tricky. As shown by our patient, on rare occasions, desmoid tumors can lead to acute surgical abdomen requiring an emergency operation.

We herein report a rare case of an intra-abdominal desmoid, consisting of solid and cystic components covered with epithelial linings, that emerged after distal gastrectomy. The preoperative diagnosis was inconclusive, so laparotomy was performed. Histopathology of the solid component showed proliferating spindle cells, which were positive for beta-catenin in their nuclei. Clinicians need to bear in mind that desmoids can appear in a solid-cystic form, and immunostaining of beta-catenin should be applied for tumors that emerge around postoperative wounds.

The role of patient groups has grown steadily stronger since the first General Meeting of cancer patients in 1999 and the emergence of the rare diseases issue in the mid-eighties. This article demonstrates the role of a patient group (SOS DESMOIDE) gathering people suffering from a rare disease (the desmoid tumor) in the stimulation of scientific and medical research as well as the improvement of patient care, information and support provided to patients. It substantiates these elements with numerous socio-medico-psychological surveys, scientific publications and medical research implemented by medical teams and supported, even sometimes initiated, by SOS DESMOIDE. This research effort illustrates the significant impact of a partnership between patients and physicians-researchers on medical and scientific breakthroughs in a specific pathological field.

We summarize here available data about systemic treatments of desmoids tumors, as well in adult patients as pediatric patients. Until 2018, the level of evidence associated with these treatments (NSAI, hormonal therapies, tyrosine kinase inhibitors, chemotherapy) was very low, based on retrospective studies or non-randomized phase 2 trials with limited number of cases. In 2018-2019, 2 large randomized trials have been published, including one large superiority phase 3 trial comparing sorafenib to placebo. This trial clearly demonstrates the clinical benefit of sorafenib over placebo (level of evidence IA). To conclude, wait-and-see policy must be the first-line approach, systemic treatment is indicated in case of disease progression. Randomized trials are feasible in this exceptional disease.

After an adapted imaging, the diagnosis of a desmoid tumor (DT) is provided by a percutaneous microbiopsy, with a molecular analysis for beta-catenin or APC gene mutation. The therapeutic strategy must be decided in a specialized multidisciplinary tumor board (MTB). Surgery is no longer the first-line treatment for a DT. Except within a surgical complication, active surveillance is offered to the majority of patients, since more than half stabilize or regress after an initial progression, whether the location is peripheral or intra-abdominal. If the localization and/or volume are likely to be functional or life-threatening, medical induction therapy is discussed in MTB, before a local treatment whose potential sequelae would be definitive. Incomplete unplanned resection, recurrence, pregnancy or desmoids occurring in a polyposis context are no longer routine surgical indications. In an emergency setting (occlusion, peritonitis), it is discussed to treat only the mechanical complication and leave the DT in place, if its resection would lead to too much digestive resection, especially in patients who have already undergone colectomy for polyposis. The best indications for surgery are patients who have parietal locations with significant and documented progression, because surgery can be easily completed at the cost of an acceptable morbidity. In localizations where surgery would cause sequelae, medical treatment or other regional loco treatments are discussed in MTB.

The aim of the present study was to investigate the clinicopathological and molecular characteristics of abdominal DT in a Chinese population and to provide clues for selecting the optimal treatment strategy for different types of abdominal desmoid tumors (DT). The clinicopathological data of 15 consecutive patients with DT was collected. A review of the patient clinicopathological characteristics revealed that F.A.P.-associated DT exhibited a higher rate of abdominal surgery history (P=0.011), with no significant differences in any other characteristics. Sequencing revealed that mutations in the APC, CTNNB1 and MUTYH genes were common in DT, and only one patient harbored no mutations in these genes. Survival analyses revealed that patients with FAP exhibited shorter time to progress TTP (P=0.030). Log-rank test demonstrated a tendency towards shorter TTP in the cases where an R2 resection was performed (P=0.072) and a tendency towards poor prognosis in the cases of DT associated with FAP (P=0.087). In conclusion, Abdominal DTs were prone to occur in patients with FAP with a history of abdominal surgery. Mutations in the APC, CTNNB1 and MUTYH genes were detected in patients with DTs. To the best of our knowledge, this is the first study of abdominal DT occurrence in patients with MUTYH-associated FAP. The prognosis of DT associated with FAP may be worse compared with that of sporadic DT.