Giant aggressive intra-abdominal desmoid-type fibromatosis – case report

Summary

Introduction: Aggressive fibromatosis, also known as desmoid tumour (DT), is a locally invasive soft tissue malignancy originating from fascial planes, connective tissue, and musculoaponeurotic structures of the muscles. The symptoms greatly depend on the location and size of the tumour.

Case report: A 68-year-old male patient without any comorbidities with a large, palpable mass in the abdomen underwent computed tomography (CT) of the abdomen during diagnostic examination in September 2017 in another centre. The CT scan revealed a giant intraperitoneal 30×40cm tumour without signs of infiltrating the surrounding organs and large vessels. The tumour biopsy revealed an aggressive DT. The patient was scheduled for tumour resection. Midline laparotomy was performed in the supine position under general anaesthesia. After gaining access to the abdominal cavity, 8 litres of clear ascites were evacuated. The tumour was not attached to the abdominal wall. Large omentum was freed from the DT. The perioperative finding confirmed the CT images of DT encapsulation of the medial colic artery, part of the small intestine, and transverse colon. The tumour was resected with part of the mesenteric radix, 30 cm of small intestine, and 2/3 of the transverse colon. After the DT was removed entirely, the small intestine was re-anastomosed end to end. The abdominal cavity and the liver were carefully checked for bleeding. The abdominal cavity was closed in a standard manner.

Results: The postoperative hospital stay was uneventful. The patient was discharged on the 7th postoperative day with prophylactic low weight molecular heparin for one month. Currently, we have five months of follow-up with no signs of DT recurrence based on CT examination. The histology of the resected tumour confirmed the diagnosis of a desmoid tumour (aggressive abdominal fibromatosis).

Conclusion: Desmoid tumours are benign neoplasms with no metastatic potential. However, their treatment is challenging due to their aggressive growth, infiltrative behaviour, and a high tendency to recur.

Keywords:

abdominal – fibromatosis – desmoid tumour

INTRODUCTION

Aggressive fibromatosis, also known as desmoid tumour (DT) is a locally invasive soft tissue malignancy originating from fascial planes, connective tissue, and musculoaponeurotic structures of the muscles [1]. The symptoms greatly depend on the location and size of the tumour. Even though these tumours cannot metastasise, they are locally invasive, causing pain and deformities that can make surgical treatment difficult [2]. The exact aetiology of DT is unknown. Trauma, hormonal and genetic factors are thought to be correlated with DT [2]. DTs are more common in women with 2:1 female predilection. Young adults at 25–35 years of age are most commonly affected [3]. Up-to-date, there are no direct therapies or standardised treatment plans. Radiotherapy, CHT, tamoxifen, tyrosine kinase inhibitors, nonsteroidal anti-inflammatory drugs and surgery often have only a temporary effect [4]. Approximately 23–50% of patients have a recurrence after surgical resection of the DT [5].

CASE REPORT

A 68-year-old male patient without any comorbidities with a large, palpable mass in the abdomen underwent computed tomography (CT) of the abdomen during diagnostic examination in September 2017 in another centre. The CT examination revealed a giant intraperitoneal 30×40cm tumour without signs of infiltrating the surrounding organs and large vessels. Tumour biopsy revealed an aggressive DT low-grade sarcoma. The patient’s lung CT scan was negative. Chemotherapy (CH) with methotrexate and vinorelbine was started in January 2018. Despite the six months of CHT, the tumour progressed in size. The patient refused to continue the treatment due to adverse effects of the CHT. The patient refused further treatment of the DT. The DT expanded over time, causing abdominal discomfort and pain to the patient as well as decreased mobility due to the tumour’s immense size. The patient was referred to our centre for evaluation in May 2021. A new CT revealed a massive intra-abdominal DT sized 50×55 cm, compressing the intestine and intraabdominal organs; part of the small intestine was encapsulated by the tumour, no infiltration was observed in the surrounding organs or large vessels and no significant vessel compression was present; medial colic artery was encapsulated (Fig. 1). Lung CT was negative. The patient was scheduled for DT resection.

The procedure was performed in the supine position under general anaesthesia via midline laparotomy (Fig. 2). After gaining access to the abdominal cavity, 8 litres of clear ascites were evacuated. The tumour was not attached to the abdominal wall. Large omentum was freed from the DT. The perioperative finding confirmed the CT images of DT encapsulation of medial colic artery; part of the small intestine and the transverse colon were attached to the tumour (Fig. 3). The tumour was resected with part of the mesenteric radix, small intestine in the length of 30 cm, and 2/3 of the transverse colon (Fig. 4). After the DT was removed entirely, the small intestine was re-anastomosed end to end. Biosyn 4/0 (B Braun, Germany) was used for the intestinal anastomosis. The abdominal cavity and the liver were carefully checked for bleeding. The abdominal cavity was closed in a standard manner. Perioperative blood loss was 1 litre.

The postoperative hospital stay was uneventful. The patient was discharged on the 7th postoperative day with prophylactic low weight molecular heparin for one month.

Histology of the resected tumour: desmoid tumour (aggressive abdominal fibromatosis). Immunohistochemistry of the DT: actin SMA: negative, CD 34: negative, KI 67: nuclear positivity in 2% of the cells. Currently, we have five months of follow-up of the patient with no signs of DT recurrence based on CT examination.

DISCUSSION

DT is defined as clonal fibroblastic proliferation of soft tissue with infiltrative growth, with a high rate of local recurrence after surgical tumour extirpation [6]. DT has an incidence of 0.03% of all neoplasms and 3% of all soft tissue tumours [7]. DTs are associated with the familial adenomatous polyposis syndrome in 2–15% of cases [8]. Furthermore, correlation with familial infiltrative fibromatosis, hereditary desmoid disease, and Gardner syndrome has been observed [9].

Due to the high rates of DT recurrence after surgical resection, radiotherapy is essential for the treatment of patients with positive resection margins. As shown by Ergen SA, et al, 5-year DT recurrence-free period after radiotherapy was 81% vs 53% in patients who underwent surgery alone [5,10]. Tumour size is another prognostic factor as tumours over 8 cm in size have a higher probability of recurrence [11].

So far, there are no direct therapies or standardised treatment plans. DT treatment protocols range from simple surveillance to surgery, radiation therapy, CHT, hormonal therapy, nonsteroidal anti-inflammatory drugs, and tyrosine kinase inhibitors. However, the 5-year progression-free survival period for surveillance vs surgery is almost identical: 49.9% vs 58.6% [12]. In a study by Alman B, et al using surveillance strategy, spontaneous regression of DT was 20% [13]. This method is not applicable in symptomatic patients or patients experiencing fast or life-threatening tumorous expansion.

In some patients DT infiltration of the surrounding anatomical structures makes surgical resection impossible. Multivisceral transplantation (MVTx) can be considered in the treatment of these patients after careful evaluation [14]. With the evolvement of transplantation and the refinement of surgical techniques, the fatal outcome in patients after MVTx is becoming less frequent [15]. This refinement of surgical techniques was shown in Janousek L, et al where MVTx was combined with kidney auto-transplantation [16]. Although our experience with MVTx in intra-abdominal malignancies is generally limited, MVTx is starting to be considered as a possible treatment option in a wide spectrum of intra-abdominal malignancies [14].

A significant number of DTs in women occur within 24 months after pregnancy, mainly in the abdominal wall. The risk of DT progression is high during pregnancy due to hormonal changes. However, DTs can be safely managed and are not a direct contraindication for pregnancy. Fiore M, et al showed in his group of 92 patients that only 17% experienced further progression after treatment; spontaneous regression occurred in 14%, and after further pregnancies 27% DTs progressed [17].

Supportive care is an interesting topic when considering patients with DT. Only limited case series have been published up-to-date. Pain management is a major topic in patients with large tumours or with tumours compressing surrounding anatomical structure. As shown by Emori M, et al, pain caused by the tumour is related to the overexpression of cyclooxygenase- 2 [18].

New pharmacological treatments are emerging. Several studies have suggested β-catenin/Wnt and Notch pathway inhibitors [19, 20]. PF-03084014 is an oral reversible γ-secretase inhibitor. In a phase I trial, partial response was observed among patients diagnosed with advanced DT. In a phase II trial with 17 patients diagnosed with DT, the response rate was 30%, with the 71% rate of stable disease. No progression was detected after a median follow-up of 23 months [21].

The unpredictable behaviour of DT should be assessed individually in each patient to improve the efficiency of tumour control. A multidisciplinary approach should be taken in the treatment of every patient.

CONCLUSION

Desmoid tumours are benign neoplasms with no metastatic potential. However, their treatment is challenging due to aggressive growth, infiltrative behaviour, and a high tendency of recurrence. Every patient should be treated individually using a multidisciplinary approach combining oncological surgical and radiological insights.

Conflict of interests

The authors declare that they have not conflict of interest in connection with this paper and that the article has not been published in any other journal, except congress abstracts and clinical guidelines.

MUDr. Robert Novotny

Transplant Surgery Department,

Institute for Clinical and Experimental Medicine,

Videnska 1958/9

140 21 Prague

e-mail: novr@ikem.cz

ORCID: 0000-0002-5876-2951