Occurrence of a desmoid tumour in a status post appendicectomy: A case report

Abstract

Introduction and importance

Tumours arising from previous sites of appendicectomy are a rare phenomenon. There have been few documented cases in literature but for the most part, it is a rare occurrence that needs further investigation.

Case presentation

A 20-year-old male presented to our outpatient with a large mass in his right upper abdomen for 2 months and a history of an appendicectomy done in an outside hospital 4 years prior.

Clinical discussion

After regular investigations, the tumour was resected with adequate margins. On immunohistochemistry, the specimen was said to be of a desmoid fibromatosis. The exact aetiology of the disease cannot be determined unless we get a thorough analysis of the appendix specimen.

Conclusion

This paves the way to the learning curve, which is that we must ensure proper patient follow-ups with relevant histopathological reports to ensure complete and comprehensive care to the patient.

Highlights

• •Masses in the abdomen post appendicectomy are a cause for concern.
• •Patient with a mass and a history of an appendicectomy due to acute appendicitis
• •Desmoid tumours of the colon are very rare.
• •Importance of post-operative pathological reports to complete the care

1. Introduction

Desmoid tumours are aggressive, generally, benign tumours with a tendon-like consistency and are often referred to as aggressive fibromatosis or deep musculoaponeurotic fibromatosis. They typically occur over the deep soft tissues, more often in the abdominal wall although there are instances of incidence in other locations. [1] Tumour-related fatalities are often due to local invasion, and tumour-related destruction of adjacent structures especially with patients who have long associations with familial adenomatous polyposis (FAP) and Gardener syndrome. The pathophysiology consists of the proliferation of fibroblasts though the exact cause has been attributed to genetic mutations, particularly the APC gene [2]. Diagnosing desmoid tumours requires a culmination of CECT, MRI reports along with histological correlation with immunohistochemistry to identify the specific markers to confirm unequivocally. Treatment modalities vary from surgical resection to radiation therapy. We present the unique case of a 20-year-old male with an intraabdominal desmoid post appendicectomy.

2. Methods

This is a single, retrospective case series. The case report is reported in line with the SCARE guidelines [3].

3. Case report

3.1. Patient information and timeline

A 20-year-old male presented with complaints of a mass in the right upper abdomen for 2 months associated with pain. The patient was in his usual state of health until around 2 months back when he realised, he had a mass on the right side of his abdomen which had been gradually increasing in size since. He had a diffuse, continuous, dull aching type of pain over the mass site. He had a significant history of previous appendicectomy with ileostomy performed in 2020 due to an appendicular perforation with obstruction. He reported no positive family history.

3.2. Clinical findings

Upon general physical examination, he was adequately built and nourished. The abdomen appeared navicular. A scar 7 cm in length was noted in the right iliac region corresponding to a past appendicectomy. A fullness was noted in the right hypochondrium extending to the right lumbar region. On palpation, the abdomen was soft and a 10x10cm mass was present in the right hypochondrium extending to the right lumbar region. It was firm in consistency. The margins appeared irregular. On percussion, a tympanic note was present over the abdomen and a dull note over the mass.

3.3. Diagnostic assessment

Upon admission, the blood workup was unremarkable with a haemoglobin of 16.08, total counts of 6280, and normal liver and renal function tests. The serum amylase was 53, CA 19-9 was 6.9, and CEA was 2.990. A colonoscopy was planned and performed with the results being that of a normal bowel with no lesions, or polyps noted.

A CECT abdomen done on admission gave the impression of a large well defined heterogeneously enhancing soft tissue density lesion in the right hypochondrium and lumbar region with extents of 8.7 × 12.3 × 13.4 cm and relations superiorly abutting the transverse colon, inferior surface of the liver and gall bladder maintaining all fat planes. Medially it was seen abutting the head, uncinate process of the pancreas, D2 segment of the duodenum, and small bowel loops with maintained fat planes. It was also seen to abut the inferior vena cava with no evidence of thrombosis. Laterally it was seen compressing the ascending colon and abutting the abdominal wall with maintained fat planes. Posteriorly it was abutting the right kidney and right psoas muscle with maintained fat planes. It was also seen abutting the right renal artery with no evidence of thrombosis. Anteriorly it was seen compressing the small bowel loops. We can appreciate this in the Fig. 1, Fig. 2, Fig. 3. The final impression was that of a mesenteric desmoid tumour, with a suggested histopathological correlation. Heterogeneously enhancing lymph nodes were noted in the subhepatic region.

Fig. 1.

Axial CECT demonstrating the expanse of the tumour. The isodense nature of the tumour reveals it to be a desmoid tumour.

Fig. 2.

Axial CECT demonstrating the inferior expanse, tumour does not enter the pelvis.

Fig. 3.

Axial CECT demonstrating patent large bowel loops.

3.4. Therapeutic intervention

A USG-guided fine needle aspirate cytology was ordered and the provisional results showed a morphological spindle cell neoplasm, though a core needle biopsy was needed for a definite diagnosis. With these investigative workups, a procedure of exploratory laparotomy under general anaesthesia was planned. A midline laparotomy incision was given, deepened and the abdomen was opened in layers. A mass was noted in the retroperitoneal plane posterior to the cecum and ascending colon. The hepatic flexure and the transverse colon were free from the tumour. The right ureter and right gonadal vessels were identified, separated, and preserved. Here, the decision to proceed with a right hemicolectomy was taken. The specimen was examined grossly and it was noted that the lumen was free from the tumour and was patent (Fig. 4, Fig. 5). The previous ileostomy closure site was noted 10 cm from the ileocolic junction and was excluded in resection. End-to-end anastomosis was performed with the ileum and transverse colon. The patency of the anastomosis was noted. The rectus sheath and skin were closed and the patient was noted to be hemodynamically stable. The resected specimen was sent for histopathological analysis. The histological results were consistent with that of the CECT findings. On immunohistochemistry, the features were of desmoid fibromatosis.

Fig. 4.

Laparotomy findings showing a smooth large tumour at the right side of the mesentery.

Fig. 5.

Resected specimen after right hemicolectomy was performed.

3.5. Follow-ups and outcomes

The patient was optimised adequately and discharged. He was advised weekly follow-ups for 4 weeks. To maximise the care for this patient and ensure the absence of recurrence, the patient was advised to test for the APC gene mutation. If tested positive he must follow the National Cancer Comprehensive Network guidelines and schedule annual colonoscopies and upper endoscopy to examine the ampulla of Vater. Annual abdominal palpation with CT/MRI to rule out desmoid recurrence along with annual thyroid examinations for thyroid cancer screening [4].

4. Discussion

Desmoid tumours are very rare and account for about 0.03 % of all neoplasms [5]. Most of these tumours occur randomly with no predilection but there seems to be a 5–15 % association with FAP [6]. Thus, in the presence of multiple, cluster desmoids there might be a necessity to screen patients for familial adenomatous polyposis (colonoscopy, genetic screening). The presence of these tumours intra-abdominally suggests the occurrence of trauma or past surgeries. This raises the possibility of the initial presentation of appendicitis to be that of a desmoid tumour. There have been cases reported of appendicular and caecal desmoids [[7], [8], [9], [10]]. The unavailability of the pathological reports following the appendicectomy from the outside hospital leads to an inability to conclude the presence of a desmoid earlier on.

5. Treatment

Careful investigations like USG, CT, and MRI are necessary to determine the prognosis. Invasive investigations like FNAC or core needle biopsy are considered controversial especially since trauma to the tumour may cause further growth and invasion, but it is indeed helpful to arrive at a quick diagnosis when a decision is taken to move forward with surgery [11]. A recent development in treatment shows the “watchful waiting” as an approach initially. Studies have shown a 50 % progression-free survival with spontaneous regression of tumours with no treatment [12]. However, due to the nature of the presentation of this case with the patient having severe pain and pressure symptoms, the decision to surgically resect was taken. Wide excision while ensuring negative margins is necessary though it can prove challenging in cases with large tumours. A systemic review conducted in 2023 revealed a recurrence rate of 17.7 % (when weighted appropriately) for primary resections of the tumour. Most of these recurrences occurred in patients with desmoid tumours intra-abdominally [13]. Thus, due caution must be exercised after complete resection and continuous follow-ups must be scheduled with the patient.

6. Conclusion

This case aims to guide the attention of surgeons to practice caution while operating on cases of apparent acute appendicitis and to understand the various other complicating disease processes that arise. Pathological and histological investigations are of utmost importance in patient care and should be looked upon even after surgeries. The question remains of whether the desmoid tumour resected was that of a post-surgical recurrence of a tumour of the mesentery of the appendix or that of a de novo tumour formed due to an appendicectomy performed.

Author contribution

Kaushal Shastri: Writing - Original Draft, Visualization.

Dr. Prashant Varma: Conceptualization, Supervision.

Consent

Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.

Ethical approval

Approval by the Institutional Ethics Committee, Kasturba Medical College, Mangalore. Protocol number: IEC KMC MLR 07/2024/495.

Guarantor

Kaushal Shastri, Prashant Varma.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Conflict of interest statement

The authors declare no conflict of interest.