Two synchronous desmoids tumours of the thoracic wall: A case report

Abstract

Introduction and importance

Desmoid tumour is a rare neoplasm that develops from the fascia and musculoaponeurotic tissue. These tumours tend to local invasion. Desmoid tumours are usually solitary. We present the first case of two synchronous desmoid tumours of the chest wall.

Case presentation

A 56-year-old male with no medical history presented a painless chest wall mass. CT scan showed a deep soft tissue mass infiltrating the pectoralis major and minor muscles with an invasion of the subclavian and axillary pedicles and a second tumour infiltrating the latissimus dorsi muscle. MRI has allowed for a better study of these two masses, and a surgical biopsy confirmed the diagnosis of a desmoid tumour. The surgical resection was intra-tumoural for the anterior mass to preserve the axillary and subclavian pedicles, and the tumour resection was marginal for the posterior tumour. The postoperative course was uneventful, and an adjuvant therapy based on Imatinib was performed. The tumour residue was stabilized for two years follow-up.

Clinical discussion

Desmoid tumours are considered a locally aggressive disease. Ultrasound, CT scan, and MRI have different roles in their diagnosis. But pathological diagnosis is the “golden standard” diagnosis of desmoid tumours. The treatment of desmoid tumours is still not standardized. Surgery is the best primary treatment, but sometimes oncological resection may not be possible because of extension to the vital structure. Adjuvant therapy, like Imatinib, had demonstrated encouraging results.

Conclusion

For desmoid tumours with vital or noble structure invasion, intra-tumoural resection associated with adjuvant therapy demonstrated encouraging results.

Highlights

• •We present the first case of two synchronous desmoid tumours of the thoracic wall.
• •Desmoid tumours tend to local invasion and recurrence after surgical excision.
• •Oncological resection is the reference treatment for desmoid tumours.
• •Resection may be intra-tumoural in cases with vital structures invasion.
• •Imatinib as adjuvant therapy to intra-tumoural resection may arrest the progression.

1. Introduction

Desmoid tumour is a rare neoplasm that develops from the fascia and musculoaponeurotic tissue [1]. These tumours have a tendency to local invasion and recurrence after surgical excision. Only a few cases have been reported in the chest wall. MRI is the best imaging modality for disease characterization. Depending on the signal intensity, we can predict its histological components. Desmoid tumours are usually solitary, but multifocal desmoid tumours develop in rare cases, <5 % of all desmoid tumours [2]. Herein, we present a rare case of two synchronous desmoid tumours in the chest wall of a 56-year-old male, which was discovered accidentally due to a thoracic wall mass that extended outward from the pectoral region.

This work has been reported in line with the SCARE criteria 2020 [3].

2. Presentation of case

A 56-year-old man with no personal or family medical history presented to the orthopaedic department for a painless mass in the chest wall extending outward from the right pectoral region. Physical examination revealed a painless mass in the anterior chest wall with a firm consistency on palpation. Neurological and vascular examination of the upper limbs was unremarkable.

We started imaging exploration with a CT scan that showed a deep soft tissue mass anterior to the right thoracic wall measuring 190 ∗ 170 ∗ 110 mm, infiltrating the pectoralis major and minor muscles with similar density to the skeletal muscle. It extends upwards to the subclavian region and outwards to the axillary region, with an invasion of the subclavian and axillary pedicles. A second tumour of the thoracic wall presenting the same characteristics, infiltrating the latissimus dorsi muscle, and measuring 76 ∗ 54 mm, was also discovered.

On MRI, the anterior mass shows a heterogeneous hyperintense signal on T2- weighted images (WI) and an isointense heterogeneous signal on T1-WI, with a peripheral enhancement (Fig. 1). And a “band sign” characterized this lesion: an hyperdensity on the CT scan with no enhancement, parallel to a hypo signal on the T1- and T2-WI without enhancement corresponding to the dense collagenous stroma (Fig. 2). The second tumour presented the same characteristics.

Fig. 1.

CT scan and MRI sections of deep soft tissue mass anterior to the right thoracic wall, infiltrating the pectoralis major and minor muscles.

A: Axial CT section without enhancement showed similar attenuation as the skeletal muscle.

B: Axial CT scan section with an enhancement: green arrow.

C: Axial MRI section, a heterogeneous hyperintense signal on T2-wi.

D: Axial MRI section, a heterogeneous iso-intense signal on T1-wi.

E and F: Axial MRI sections, T1-wi with contrast: blue arrow.

Yellow arrows: the “Band sign”: a hyper density on CT scan with no enhancement and low-signal intensity on both T1- and T2-weighted images with no enhancement that corresponds to the dense collagenous stroma.

Fig. 2.

Axial MRI sections of deep soft tissue mass infiltrating the latissimus dorsi muscle. White arrows: low-signal intensity on both T1- and T2-weighted images with no enhancement.

A surgical biopsy of the anterior mass was performed, and it confirmed the diagnosis of a desmoid tumour. The patient had surgery. We use an enlarged anterior approach next to the superior and medial edge of the anterior tumour, covering the biopsy scar (Fig. 3). The surgical resection was intra-tumoural to preserve the axillary and subclavian pedicles (Fig. 4). We used a second approach centred on the posterior tumour (Fig. 3), and the tumour resection was marginal. The postoperative course was uneventful. An adjuvant therapy based on Imatinib was associated.

Fig. 3.

Photos of used surgical approaches.

A: The anterior approach.

B: the posterior approach.

Fig. 4.

Photos of the resected tumour.

A: Photo of surgical resection of the anterior tumours and its invasion to the auxiliary pedicle.

B: Photo of the resected anterior tumour.

C: The cut surfaces of the tumour are shiny white similar to scar tissue.

Two years after the postoperative follow-up, the clinical examination was unremarkable. The patient had a follow-up MRI which showed a tumour remnant of 30 ∗ 60 cm next to the subclavian and axillary pedicles and a second residue of 20 ∗ 30 mm on the right parasternal in contact with the pleura (Fig. 5).

Fig. 5.

Two years post-operative control MRI. Axial sections showed a 30 ∗ 60 cm tumour remnant next to the subclavian and axillary pedicle and a 20 ∗ 30 mm tumour residue in the right parasternal in contact with the pleura.

3. Discussion

Desmoid tumour is a rare neoplasm that develops from the fascia and musculoaponeurotic tissue [1]. These tumours tend to local invasion and recurrence after surgical excision. But they have no metastatic potential. They are sometimes considered a locally aggressive proliferative disease. Desmoid tumours account for approximately 3.5 % of fibrous tumours, 0.3 % of all solid tumours, and only 0.03 % of all neoplasms [4], [5]. It can occur in almost any anatomical region but is typically found in the abdomen [6], the chest wall represents 8–10 % of cases, and the tumour is exceptionally intrathoracic [5]. It is common in females of childbearing age (between 20 and 40 years) [1].

Its pathogeny is diverse and uncertain. Trauma, abnormal oestrogen level, genetic factors and surgery are considered the most common causes [1]. Different mutations of β-catenin have been described in desmoid tumours [7]. Desmoid tumours are usually solitary, but multifocal desmoid tumours develop on rare occasions in <5 % of all desmoid tumours [2]. Desmoid tumours can be sporadic or associated with familial adenomatous polyposis, specifically with Gardner's syndrome [2], [8]. To our knowledge, this case is the first case of two synchronous desmoid tumours of a thoracic wall without Gardner's syndrome.

Desmoid tumours are deep, painless, hard-textured soft tissue masses. Ultrasound, CT scan, and MRI have different roles in their diagnosis, depending on their locations and clinical presentation. Ultrasound examination is the first-line imaging technique to evaluate a palpable mass. A desmoid tumour is an oval, solid soft tissue mass with smooth or irregular margins and variable echogenicity [9]. Due to its heterogeneous composition, it can be characterized by alternating layers of hypo- (matrix and collagen) and hyper-echogenicity (cells). Vascularization, assessed on colour Doppler ultrasound, can be variable [9]. On CT scans, it is often a well-defined mass. Density may be lower, similar or higher than skeletal muscle. A higher density is secondary to prominent collagen components or fibrotic lesions [10], and lower-density lesions reflect elevated myxoid substances [10]. MRI is the best imaging modality for the characterization of the disease. Tumours appear as a heterogeneous mass with a variable signal on T2-WI and T1-WI [9]. Decreased T2 signal correlates to dense collagen and hypocellularity, while an increased T2 signal correlates with high cellularity. The contrast enhancement is variable and depends on the cellularity of the mass.

Pathological diagnosis is the “golden standard” diagnosis of desmoid tumours. Macroscopically, they had a firm, grainy texture. On the cut surface, they are shiny white similar to scar tissue and lack a true capsule [11]. Microscopically, they are composed of dense collagenous stroma and uniform fibroblasts with low cellularity [9]. Immunohistochemistry also participates in diagnostic confirmation, such as positivity for smooth-muscle actin and b1-catenin [9].

Currently, the treatment of desmoid tumours is not standardized, and there are varied clinical treatments for desmoid tumours. Surgery is the best primary treatment, but sometimes oncological resection may not be possible because of extension to vital structure, like in our case. Adjuvant therapy, like radiotherapy, cytotoxic chemotherapy, and some non-steroidal anti-inflammatory drugs (sulindac), are discussed in the literature but without having proven effectiveness [12], [13], [14]. However, many studies evaluating the effect of Imatinib as an adjuvant therapy have demonstrated encouraging results by showing a prolonged arrest of the progression of desmoid tumours in patients [15], [16].

Recurrences occur on average in 50 % of cases; several predictors factors have been reported in the literature, such as young age (<30 years), female sex, location (recurrences are more frequent at the extremities), tumour size (>7 cm), and the quality of the excision margin [1], [17], [18]. The worst factor of severe prognosis, as in our case, was the deep location and the positive resection margins, as reported in the literature [5].

4. Conclusion

Desmoid tumours are rare and locally aggressive tumours. To our knowledge, this case is the first case of two synchronous desmoid tumours of the thoracic wall without Gardner's syndrome. Imaging and Pathological study play a principal role in the diagnosis. Given their high recurrence, the reference treatment for these tumours is surgery with oncological resection. However, in cases with a vital or noble structures invasion, such as the vascular-nervous pedicle, surgical resection could result in significant functional disability. As the presented case, intra-tumoural resection associated with adjuvant therapy based on Imatinib could lead to a prolonged arrest of tumour progression.

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

Ethical approval is waived at our institution.

Funding

No funding was received to assist with the preparation of this manuscript.

Guarantor

Oueslati Achraf.

CRediT authorship contribution statement

• Achraf Oueslati: Original draft writing

• Amine Briki and Zayed Filali: Data collection and processing

• Souad Ferjani: Assist with data analysis

• Naoufel Hadded: Supervision.

Conflicts of interest

The authors have no relevant financial or non-financial interests to disclose.