DESMOID TUMOR OF ANTERIOR ABDOMINAL WALL: A CASE REPORT AND REVIEW OF RECENT MANAGEMENT STRATEGIES

Desmoid Tumor of Anterior Abdominal Wall: A Case Report and Review of Recent Management Strategies

Divyesh Rana¹, Anil Goel², Vimal Batra³

¹Assistant Professor, Department of Radiotherapy, Medical College and SSG Hospital Baroda, Vadodara. (India)

² Professor, Department of Radiotherapy Medical College and SSG Hospital Baroda, Vadodara. (India)

³Professor and Head, Department of Radiotherapy, Medical College and SSG Hospital Baroda, Vadodara. (India)

Abstract: Desmoid tumor is a slow growing neoplasm with aggressive infiltration of adjacent tissue with very rare metastatic potential. We report a 35 years old female patient with desmoid tumor of the anterior abdominal wall who underwent primary resection followed by mesh pasty. Patient had a past history of abdominal surgery in form of caesarean section, and after 5 years of surgery, she presented with a lump over right hypochondrium since last one year. Patient was assessed before surgery by clinical evaluation, abdominal ultrasound, computerized axial tomography scanning (CT scan), magnetic resonance imaging (MRI), and histopathology and immunohistochemistry report.Patient was operated with wide local excision of rectus abdominis muscle mass with meshplasty under general anaesthesia. After all, histology in this case revealed a desmoid tumor with negative β-Catenin report of operated tissue. In view of the negative surgical margins, patient has been put on regular follow up.

Keywords:

Abdominal Wall, β-Catenin, Desmoid Tumour, Metastatic Potential, Surgery.

Introduction

Desmoid tumors benign myofibroblastic neoplasms usually originating from the muscle aponeurosis and classified as aggressive fibromatoses¹. They constitute 3% of all soft tissue tumors and 0.03% of all neoplasms². Despite their aggressive local infiltration, desmoid tumors usually lack a metastatic potential³. However, because of this local infiltration and compression of surrounding structures, a high recurrence rate exists and in anatomic locations with restricted access to surgical resection, desmoid tumors can lead to significant morbidity and mortality. In patients with familial adenomatous polyposis (FAP), undergoing prophylactic colectomy, desmoid tumors are the leading cause of morbidity than colon cancer⁴.

Molecular studies demonstrated desmoid tumors in FAP as clonal neoplasms arising from germline mutation or changes in the adenomatous polyposis coli (APC) alleles^{5, 6,7}. Cytogenic data has verified clonal chromosome aberrations in deep-seated sporadic extra-abdominal fibromatoses and lesions of the abdominal wall and therefore provide additional evidence for the neoplastic nature of these lesions⁸.

The locations of desmoid tumor may vary from abdominal wall of young pregnant females to intra-abdominal mesenteric masses to large extremity masses in males and females. In sporadic cases, they occur in localizations of trauma, and scars or irradiation. The therapeutic management of these tumors is still controversial⁹.

Case Report

A 35-year-old female patient reported with a history of abdominal surgery in the form of caesarean section in 2010, and after 4 years, in the year 2014, she presented with a history of lump over right hypochondrium for 1 year. On clinical examination, a painless mass was found without any fixity to surrounding bony structures.

On investigation, blood parameters were within normal range and tumour markers were negative, while ultrasonography of abdomen suggested an approximately 33 x 19 x 23 mm size of hyperechoic lesion with no internal vascularity noted in right rectus muscle suggestive of benign lesions.

On further evaluation, MRI was done to localize the tumor and to exclude metastasis ​(Figure 1).

MRI of chest, abdomen and pelvis showed a bulky lesion in epigastric region on right rectus abdominis muscle and reveals ill defined hypo dense lesion measuring 25 x 16 x 20 mm. Moreover, no evidence on intra abdominal extension or obvious bony pathology was detected, which was suggestive of muscle pathology.

The MRI finding revealed tumor's hypo-intensity on T1 and demonstrates variable signal intensity on T2 weighted imaging, depending on the accumulation of mucoid structures (Figure 2).

Patient underwent wide local excision of rectal muscle mass with meshplasty under general anesthesia. The postoperative course was uneventful and the patient was discharged on the eighth postoperative day.

Histopathological examination of specimen of excision biopsy

Histopathological report of operated soft tissue mass had shown following findings:

On macroscopic examination, surgical specimen was creamish brown soft tissue mass like structure, with about 80 x 60 x 20 mm size with external surface being irregular white, homogenous about 35 x 17 x 10 mm with infiltrating margin. No necrosis or haemorrhagic area was noted on gross examination.

On microscopic examination of the resected specimen, a Fibromatosis of abdominal wall, in other word it was a Desmoid Tumour.

As shown in figure 5, in this patient, Immunohistochemistry report of β-Catenin was negative, and according to previous studies, nuclear staining of β-Catenin is supportive, but not definitive for the diagnosis of desmoid fibromatosis¹⁰. Moreover, negative results of such an assay would not preclude the diagnosis of desmoid. However, given that most desmoids harbour CTNNB1 gene mutations, a positive result for such mutation would serve to confirm a diagnosis of desmoid; other benign lesions included in the differential diagnosis are not known to have CTNNB1 gene mutations nor they show nuclear expression of β-Catenin on Immunohistochemistry¹¹.

Discussion

Desmoid tumours are benign deep fibromatoses, which originates from fascia and muscle aponeurosis with an infiltrating growth¹². They are primary located abdominally or intraabdominally, whereas only sporadic cases describe a localisation within the thorax wall¹³ or retroperitoneally¹⁴. Desmoid tumor is generally associated with female gender, FAP¹⁵ and occasionally with surgical trauma¹⁶. It has shown a higher prevalence in women who experienced caesarean section during pregnancy¹⁷. Depending on the tumors size, on the therapy and negative resection margins, recurrence occurs in up to 45%¹⁸.

Histology is the only evidentiary method which confirms diagnosis by showing long fascicles of spindle cells of variable cell-density with few mitoses and absence of atypical nucleus-separations with diffuse cell infiltration of adjacent tissue structures¹⁹.

Surgery is the primary treatment for resectable desmoid tumors. Some studies have reported margin status as independent prognostic factor of recurrence. Other studies have failed to provide any clear association between resection margin status and risk of recurrence¹⁷.

So in case of symptomatic patient with resectable tumor, wide excision should be done. The effectiveness and indication of adjuvant radiation is not proven yet. In a comparative analysis, a significantly better local recurrence control was described with radiation and combined surgical resection in comparison to resection only^17,24. Other studies have shown that a tumor can progress after radiation therapy and it can show higher local recurrence rate^20,21.

If resection margins are negative (R0), patient should be kept on observation. If resection margins are microscopically positive (R1), observation or re- resection may be done. In case of macroscopically positive margins (R2), various options are; definitive radiotherapy, resection plus radiotherapy, systemic treatment, radical surgery or observation etc²⁴.

On the other hand, for unresectable desmoid tumor, definitive radiotherapy (54-58 Gy in absence of prior radiotherapy, only in desmoids tumors of extremities, superficial trunk and head & neck regions), systemic treatment and observation are the options. Radiotherapy is usually not given in intra-abdominal and retroperitoneal desmoid tumors.

Recent NCCN guideline (version 1.2015) has included NSAIDS like sulindac or celecoxib, hormonal or biological agents (tamoxifen, toremifine, or low dose interferon), chemotherapy (methotrexate and vinblastine or doxorubicin based regimens), and tyrosine kinase inhibitors (imatinib or sorafenib) are used as systemic treatment for advanced and unresectable desmoid tumors.

Moreover, anti-inflammatory treatment, hormone-therapy and chemotherapy have not been proven yet to be curative. These therapies are limited to patients, in whom resection is not possible because of a widespread tumour infiltration.

Figure 6 NCCN guideline (version 1.2015) for treatment of desmoid tumour

due to the germline mutations and chromosomal aberrations of the APC alleles, Bright-Thomas et al had performed a pre-clinical study of gene transfer for the treatment of desmoid disease in FAP. Despite the success of transgene expression, further work is needed in animal models of desmoid disease to assess the clinical effects of gene therapy²⁵.

In short, surgery always aims at radical tumor resection with free margins, which, depending on localisation of surgery, may leave major soft tissue defects behind^{26, 27, 28}. Although abdominal wall integrity after full-thickness surgery can be restored with direct sutures^4,26, reconstruction with synthetic materials is a common technique in major abdominal wall defects²⁷.

Here, a small tumor resection with tumor free margins and reconstruction of the abdominal wall was performed with a Bard Composix-Mesh. According to the recent literatures’ recommendation, distant or free muscle flaps is advisable for greater abdominal wall defect coverage which is not accessible to local flaps³⁰.

Additionally, prosthetic material is more susceptible to bacterial infection and other complications²⁸, although new developed material showed encouraging experimental results ^{29, 30}.

In this case, operated tumour had shown negative margins histopathlogically and negative β-Catenin mutation, some tumours exhibit a significant tendency for local recurrence even in the setting of negative microscopic margins, others do not recur after R1 resection, and some have been observed to spontaneously regress even without therapeutic intervention³¹. So, after considering less chance of recurrence by obtaining negative histopathological and immunochemistry report for margins of surrounding tissue, patient was discharged with follow up advice as per the NCCN guideline (Figure 6).

Conclusion

In conclusion, treatment of desmoid tumor is still controversial so final treatment remains puzzling. A variety of non-surgical treatments like definitive radiotherapy, anti-inflammatory drugs, hormone-therapy and chemotherapy has been advised but they are not proven to be curative. These therapies are limited to patients, in whom resection is not possible because of a widespread tumour infiltration.

References

1. Fletcher CDM. Myofibroblastic tumours: an update. Verh Dtsch Ges Path. 1998: 82:75–82.
2. Kiel KD, Suit HD. Radiation therapy in the treatment of aggressive fibromatoses (desmoid tumors) Cancer. 1984: 54:2051–2055.
3. Lewis JJ, Boland PJ, Leung DH, Woodruff JM, Brennan MF. The enigma of desmoid tumors. Ann Surg. 1999: 229:866–872.
4. Nugent KP, Spigelman AD, Phillips RK. Life expectancy after colectomy and ileorectal anastomosis for familial adenomatous polyposis. Dis Colon Rectum. 1993: 36:1059–1062.
5. Dangel A, Meloni AM, Lynch HT, Sandberg AA. Deletion (5q) in a desmoid tumor of a patient with Gardner's syndrome. Cancer Genet Cytogenet. 1994: 78:94–98.
6. Miyaki M, Konishi M, Kikuchi-Yanoshita R, Enomoto M, et al. Coexistence of somatic and germ-line mutations of APC gene in desmoid tumors from patients with familial adenomatous polyposis. Cancer Res. 1993: 53:5079–5082.
7. Palmirotta R, Curia MC, Esposito DL, Valanzano R, et al. Novel mutations and inactivation of both alleles of the APC gene in desmoid tumors. Hum Mol Genet. 1995: 4:1979–1981.
8. Wever ID, Dal CP, Fletcher CD, Mandahl N, et al. Cytogenetic, clinical, and morphologic correlations in 78 cases of fibromatosis: a report from the CHAMP Study Group. CHromosomes And Morphology. Mod Pathol. 2000: 13:1080–1085.
9. Lynch HT, Fitzgibbons R, Desmoid tumors, and familial adenomatous polyposis: case report and literature review. Am J Gastroenterol. 1996: 91:2598–2601.
10. Casillas J, Sais GJ, Greve JL, Iparraguirre Mc, et al. Imaging of intra and extraabdominal desmoid tumors. Radiographics. 1991: 11:959-968.
11. Carlson JW, Fletcher CD. Immunohistochemistry for beta-catenin in the differential diagnosis of spindle cell lesions: analysis of a series and review of the literature; Histopathology. 2007: 51(4):509-14.
12. Hasegawa SL, Fletcher CDM. Fibromatosis in the adult. Adv Pathol. 1996: 9:259–275.
13. Gacouin A, Desrues B, Lecoz A, Quinquenel ML, et al. Desmoid tumor of the thoracic wall. Rev Mal Respir. 1993: 10:554–556.
14. Budzynski A, Wysocki A. Retroperitoneal desmoid tumor. Przegl Lek. 1996: 53:506–507.
15. Soravia C, Berk T, McLeod RS, Cohen Z. Desmoid disease in patients with familial adenomatous polyposis. Dis Colon Rectum. 2000: 43:363–369.
16. De Cian F, Delay E, Rudigoz RC, Ranchere D, et al. Desmoid tumor arising in a cesarean section scar during pregnancy: monitoring and management. Gynecol Oncol. 1999: 75:145–148.
17. Gansar GF, Markowitz IP, Cerise EJ. Thirty years of experience with desmoid tumors at Charity Hospital. Am Surg. 1987: 53:318–319.
18. Nuyttens JJ, Rust PF, Thomas CR, Jr, Turrisi AT, et al. Surgery versus radiation therapy for patients with aggressive fibromatosis or desmoid tumors: A comparative review of 22 articles. Cancer. 2000: 88:1517–1523.
19. Mentzel T, Katenkamp D. Myofibroblastic tumors. Brief review of clinical aspects, diagnosis and differential diagnosis. Pathologe. 1998:19:176–186.
20. Pritchard DJ, Nascimento AG, Petersen IA. Local control of extra-abdominal desmoid tumors. J Bone Joint Surg Am. 1996: 78:848–854.
21. Rock MG, Pritchard DJ, Reiman HM, Soule EH, et al. Extra-abdominal desmoid tumors. J Bone Joint Surg Am. 1984: 66:1369–1374.
22. Waddell WR, Kirsch WM. Testolactone, sulindac, warfarin, and vitamin K1 for unresectable desmoid tumors. Am J Surg. 1991: 161:416–421.
23. Wilcken N, Tattersall MH. Endocrine therapy for desmoid tumors. Cancer. 1991: 68:1384–1388.
24. Patel SR, Evans HL, Benjamin RS. Combination chemotherapy in adult desmoid tumors. Cancer.1993: 72:3244–3247.
25. Bright-Thomas RM, Agrawal A, Hargest R. Preclinical studies of gene transfer for the treatment of desmoid disease in familial adenomatous polyposis. Br J Surg. 2002: 89:1563–1569.
26. Rohrich RJ, Lowe JB, Hackney FL, Bowman JL, et al. An algorithm for abdominal wall reconstruction. Plast Reconstr Surg. 2000: 105:202–216.
27. Bauer JJ, Salky BA, Gelernt IM, Kreel I. Repair of large abdominal wall defects with expanded polytetrafluoroethylene (PTFE) Ann Surg. 1987: 206:765–769.
28. Disa JJ, Klein MH, Goldberg NH. Advantages of autologous fascia versus synthetic patch abdominal reconstruction in experimental animal defects. Plast Reconstr Surg. 1996: 97:801–806.
29. Leber GE, Garb JL, Alexander AI, Reed WP. Long-term complications associated with prosthetic repair of incisional hernias. Arch Surg. 1998: 133:378–382.
30. Disa JJ, Chiaramonte MF, Girotto JA, Klein MH, et al. Advantages of autologous fascia versus synthetic patch abdominal reconstruction in experimental animal defects. Plast Reconstr Surg. 2001: 108:2086–2087.
31. Lewis JJ, Boland PJ, Leung DH, Woodruff JM, et al. The enigma of desmoid tumors. Ann Surg. 1999: 229:863–872.