Cryoablation as a downsizing strategy enabling R0 resection in a giant mediastinal desmoid tumor: a case report

Introduction

Desmoid tumors of the intrathoracic region are extremely rare and represent a unique clinical and therapeutic challenge. Classified among aggressive fibromatoses, they are non-metastatic but locally invasive lesions with a strong tendency for local recurrence (1). Although desmoid tumors account for approximately 3% of all soft-tissue neoplasms, thoracic and mediastinal localizations are exceptional, explaining the paucity of published data, particularly for giant lesions (2).

Diagnosis is often delayed because symptoms are nonspecific or absent at early stages. When present, they usually reflect mass effect—such as dyspnea, chest pain, or cough—rather than intrinsic tumor biology (3). Computed tomography (CT) and magnetic resonance imaging (MRI) are essential to assess tumor extent and its relationship with adjacent structures, while histological confirmation generally requires percutaneous or surgical biopsy (4-6).

Most desmoid tumors are sporadic and arise in the trunk or extremities, whereas intra-abdominal, abdominal wall, and multifocal forms are more frequently associated with familial adenomatous polyposis (FAP) (6). Although most desmoid tumors are sporadic, approximately 10–15% are associated with FAP and adenomatous polyposis coli (APC) gene mutations. In both sporadic and FAP-related tumors, dysregulation of the Wnt/β-catenin pathway leads to β-catenin accumulation and uncontrolled cellular proliferation, with CTNNB1 mutations identified in up to 80% of sporadic cases. Reported risk factors include prior trauma or surgery, particularly in FAP patients, as well as pregnancy (6-9).

Therapeutic management has significantly evolved over the past decade. According to recent international consensus guidelines, upfront radical surgery has progressively been replaced by a more conservative and stepwise approach, prioritizing active surveillance and non-surgical treatments whenever feasible (10-12). Surgical resection is now typically reserved for selected cases, particularly after tumor stabilization or response to medical or locoregional therapies. When surgery is indicated, complete resection remains the only potentially curative treatment. However, intrathoracic localization frequently precludes safe excision because of proximity to vital vascular, airway, and cardiac structures, reinforcing the importance of multidisciplinary decision-making in expert centers.

Systemic therapies—including non-steroidal anti-inflammatory drugs (NSAIDs), hormonal agents such as tamoxifen, and targeted therapies—may provide disease control in selected patients (3). More recently, percutaneous cryoablation (PCA) has emerged as a promising minimally invasive option, particularly for extra-abdominal desmoid tumors, offering local control with acceptable morbidity (13,14). The prospective CRYODESMO-O1 phase II trial demonstrated that cryoablation is a feasible and effective treatment for progressive desmoid tumors, achieving non-progression rates of 86% at 12 months, along with pain relief and functional improvement (5).

The aim of this study is to describe the role of cryoablation as part of a multimodal therapeutic strategy in the management of giant mediastinal desmoid tumors. We present this case in accordance with the CARE reporting checklist (available at https://med.amegroups.com/article/view/10.21037/med-2026-1-0004/rc).

Case presentation

A 64-year-old woman with a medical history of bilateral breast implants (removed in 2015), bilateral salpingectomy for post-tubercular adnexitis [1990], hysterectomy with bilateral oophorectomy [2013], and a monitored left breast mass since 2018, presented in 2020 with a persisting cough over 3–4 months.

The clinical timeline is summarized in Figure 1.

Figure 1 Clinical timeline. MDT, multidisciplinary team.

Clinical findings and diagnostic assessment

CT performed in October 2020 revealed a giant left anterior-superior mediastinal mass measuring 15 cm × 9 cm, associated with probable obstructive atelectasis due to compression of the trachea and left main bronchus (Figure 2). The patient reported increasing positional pain and respiratory discomfort. Positron emission tomography-CT (PET-CT) did not show distant disease, and the primary tumor demonstrated moderate metabolic activity, with an initial standardized uptake value (SUV) of 1.8. A CT-guided percutaneous biopsy confirmed the diagnosis of desmoid-type fibromatosis.

Figure 2 Percutaneous cryoablation procedure. (A) Frontal and (B) lateral views of trocars inserted via a left anterior approach under fluoroscopic control. (C) Correct positioning of trocars confirmed with non-contrast CBCT. CBCT, cone-beam computed tomography.

Initial management consisted of hormonal therapy with tamoxifen combined with NSAIDs. In March 2021, targeted therapy with a tyrosine kinase inhibitor (imatinib) was introduced due to concern for potential progression. Given the tumor size and its intrathoracic extension with close relationships to critical mediastinal structures, including the great vessels and other mediastinal organs, surgical resection was initially considered unsafe and therefore not retained as a therapeutic option. This decision followed careful evaluation of imaging findings during multidisciplinary tumor board discussions and surgical team review, which indicated that resection would likely require a highly invasive procedure with a substantial risk of incomplete resection (R1–R2) or even exploratory sternothoracotomy without safe tumor removal. The case was repeatedly reviewed during local multidisciplinary oncology meetings and further discussed with the regional sarcoma reference multidisciplinary team. Given the initial surgical contraindication related to the tumor’s extensive mediastinal involvement and the lack of response to prior medical therapies, cryoablation was proposed as an alternative local treatment strategy. No further systemic treatment was administered thereafter. This decision was supported by the recently published prospective CRYODESMO-O1 trial (5), which reported promising outcomes for cryotherapy in desmoid tumors.

Cryoablation

In December 2021, the tumor measured 13 cm × 12 cm × 8 cm, corresponding to an estimated volume of approximately 1,250 cm³ (Figure 3). PCA was performed by the interventional radiology team under general anesthesia with the patient in the supine position. Intraoperative cone-beam computed tomography (CBCT) was used to plan three access trajectories. To ablate the maximum volume of the tumor while minimizing the number of probes, the following strategy was applied:

• A cryoablation device (ProSense^TM, IceCure Medical HQ, Caesarea, Israel) capable of generating a 5 cm × 5 cm × 4.5 cm ice ball using a 10-G cryoprobe (IceCure^TM IceCure Medical HQ) per cycle (5’ freeze, 5’ thaw and 12’ freeze);
• A triangular equilateral configuration (2.5 cm sides) using three 20-cm trocars, allowing insertion of 10-G cryoprobes into the central part of the tumor along its long axis (antero-posterior and infero-superior orientation) (Figure 2);
• A pull-back ablation technique consisting of sequentially 1 cm-overlapped ice balls created by withdrawing the probes in 4-cm steps along each trocar from the postero-superior to inferior limits of the tumor (three ablation cycles per trocar) to ensure adequate tumor coverage.

Figure 3 Serial CT scans at different clinical time points. October 2020: diagnostic time; November 2021: before PCA; January 2025: after PCA; December 2025: follow-up. CT, computed tomography; PCA, percutaneous cryoablation.

Procedure planning was performed using pre-ablative 3D CBCT acquisition. Trocar insertion was guided in real time using a combination of ultrasound and fluoroscopy (Figure 2). The patient remained hospitalized for 3 days after the procedure without complications.

Follow-up and outcomes

Serial imaging from 2022 to 2024 demonstrated a progressive reduction in tumor width and improved anatomical relationships within the mediastinum (Figure 3). Cryoablation had initially been performed with a definitive intent, as the tumor was considered unresectable after failure of prior systemic therapies. On CT performed in January 2025, the residual tumor measured 9 cm × 6 cm × 7 cm, corresponding to a residual volume of approximately 350 cm³ (Figure 3), representing a reduction of approximately 900 cm³ (nearly 70%). Follow-up imaging also demonstrated the appearance of central calcifications within the portion of the tumor targeted by cryoablation. Given the marked tumor downsizing, the case was re-evaluated in a multidisciplinary tumor board. In early 2025, surgery was proposed to exploit a favorable window of opportunity for definitive local control with acceptable operative risk, prior to possible tumor progression, following extensive functional and imaging assessment.

Surgery

In April 2025, surgical resection was performed under general anesthesia using a combined median sternotomy and anterior thoracotomy approach (Figure 4). The tumor was found to be highly fibrotic and infiltrative, with close adherence to major mediastinal vascular structures and the lung. Complete macroscopic resection was achieved following meticulous dissection, including pulmonary wedge resections and esophageal mobilization. Involvement of the vagus and phrenic nerves necessitated their sacrifice. The tumor was removed en bloc, and histopathological examination confirmed complete excision.

Figure 4 Intraoperative view of left sterno-thoracotomy after desmoid tumor removal.

The postoperative course was complicated on day 10 by mediastinitis, requiring reoperation with lavage and sternal stabilization using metallic hardware. Re-exploration through the previous median sternotomy revealed sternal dehiscence with transverse fractures caused by failed steel wires, which were removed. After bacteriological sampling, sternal stability was restored using a large sternal staple combined with two STRATOS^® (strasbourg thoracic osteosyntheses system) fixation bars. Empirical antibiotic therapy with piperacillin-tazobactam was continued for 6 weeks due to negative intraoperative cultures. The patient required 8 days of intensive care and was discharged on postoperative day 24.

Final pathology revealed predominantly sclerotic scar tissue with less than 10% residual desmoid tumor, and complete R0 resection margins. Histological findings are shown in Figure 5.

Figure 5 Histological findings. (A) H&E staining (×10) showing spindle-cell proliferation with paler fibromatous nodules. (B) H&E staining (×20) showing bland spindle-shaped cells with elongated nuclei embedded in a loose collagenous matrix, with no cytological atypia or mitoses identified. (C) CD34 immunostaining (×20) highlighting intratumoral blood vessels. (D) Immunohistochemical staining (×20) for β-catenin demonstrating cytoplasmic and nuclear accumulation in tumor spindle cells, consistent with desmoid-type fibromatosis. H&E, hematoxylin and eosin.

At one-month follow-up, the patient reported complete resolution of cough. Follow-up CT showed a stable sternum, complete resolution of mediastinal collections, and no pleural effusion. At the last follow-up (8 months), the patient remained well, without evidence of recurrence.

All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Declaration of Helsinki and its subsequent amendments. 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 editorial office of this journal.

Discussion

Desmoid-type fibromatosis is a locally aggressive, non-metastatic disease characterized by an unpredictable clinical course and a high propensity for local progression or recurrence. Historically, surgery was considered the standard treatment for desmoid tumors, requiring wide excision with significant removal of surrounding healthy tissue. However, the high risk of locoregional recurrence ranging between 20% and 60% and the morbidity associated with repeated surgical procedures increasingly favor an initial active surveillance (“wait-and-see”) approach, particularly in asymptomatic patients, with treatment—including medical therapy, radiotherapy, or surgery—reserved for cases showing disease progression (15,16). Non-invasive therapies are generally preferred to limit treatment-related morbidity, especially given that spontaneous tumor regression occurs in approximately 20–30% of cases (3,6,17). Comparative studies have shown that cryotherapy provides oncological outcomes comparable to surgery, with similar local control and, in some series, higher response rates (5,18-20).

In our case, the indication for cryoablation was based on a locally advanced mediastinal tumor considered unresectable due to its anatomical relationships, with symptomatic and progressive disease despite prior systemic therapies. This indication is consistent with current evidence, where cryoablation is proposed in patients with progressive, symptomatic desmoid tumors, particularly after failure of medical treatment, as reported in the prospective CRYODESMO-O1 trial by Kurtz et al. (5). Cryoablation was selected as a minimally invasive local treatment option with a more favorable safety profile compared to upfront surgery in this context, initially with a palliative intent aimed at symptom control and local disease stabilization. Regarding complications, available data indicate that PCA is generally safe, with a low rate of major adverse events. In a systematic review and meta-analysis by Vora et al. (20), the pooled rates of complications were approximately 4.2% for major events and 10.2% for minor events. Similarly, a systematic review by Bodard et al. (13) reported major complication rates below 5%, with predominantly minor adverse events occurring in approximately 20% of patients. Reported complications include nerve injury, bleeding, infection, and skin necrosis, as well as transient pain or inflammatory reactions, with most events being manageable and often reversible. In thoracic locations, specific risks such as pneumothorax or injury to adjacent critical structures must also be considered. In terms of oncological control, cryoablation has been associated with high rates of disease stabilization. In the CRYODESMO-O1 trial, the rate of non-progressing disease at 12 months was 86%. Similarly, pooled data from the literature report progression-free survival rates of approximately 85% at 12 months and 62% at 36 months, with an overall progression rate of around 7–8%. These findings suggest that while cryoablation provides effective local control in most patients, tumor recurrence or progression may still occur, supporting the need for continued surveillance and, in selected cases, additional treatments.

In the present case, PCA was initially performed as a local treatment strategy in a patient with a large mediastinal desmoid tumor considered unresectable because of its size and its close relationship with critical mediastinal structures. During follow-up, serial imaging demonstrated progressive tumor downsizing, with an estimated volumetric reduction of approximately 70% over a 29-month period, associated with modification of the tumor’s internal architecture and improved anatomical relationships within the mediastinum. This anatomical evolution allowed reconsideration of surgical feasibility during multidisciplinary discussions and ultimately allowed complete (R0) resection of the tumor. Pathological examination confirmed a major treatment effect with extensive tumor devitalization and less than 10% residual viable tumor cells. In this context, although wide surgical margins could not be achieved due to the proximity of critical mediastinal structures, this marked pathological response may be interpreted as a reduction in the biological aggressiveness of the lesion, potentially compensating for anatomically limited margins and contributing to local control. Although a direct causal relationship between cryoablation and improved resectability cannot be definitively established in a single case report, the temporal association between the procedure and the progressive tumor regression observed on serial imaging suggests that cryoablation may have contributed to this favorable evolution. In selected cases, cryoablation may therefore represent a potential strategy to induce tumor regression and facilitate reconsideration of surgical options in patients with large thoracic desmoid tumors initially considered unresectable.

The present case adds to the existing literature in several meaningful ways. First, while contemporary guidelines advocate a conservative, stepwise approach to desmoid tumors, published data illustrating how this strategy can be successfully applied to giant mediastinal lesions are scarce. This case suggests that a sequential, adaptive strategy may ultimately lead to complete surgical resection even when initial anatomy precludes operability. Second, although PCA has been increasingly reported as an effective treatment for desmoid tumors, its role has primarily been described as a definitive locoregional therapy aimed at disease control or symptom palliation. In contrast, this case highlights cryoablation as a purposeful tumor downsizing tool. Rather than targeting complete ablation, the intervention was integrated into a long-term treatment plan with the specific objective of modifying tumor geometry and mediastinal relationships. The observed progressive reduction in tumor size was sufficient to transform an initially unresectable tumor into one amenable to surgical resection. Third, this case expands the clinical implications of the CRYODESMO-O1 trial (5). While the trial demonstrated high non-progression rates, pain relief, and functional improvement, it did not specifically address the potential of cryoablation to facilitate delayed curative surgery. Our observation suggests that, in selected patients, cryoablation may serve not only as a disease-controlling modality but also possibly as a bridge to secondary R0 resection. The favorable evolution of our patient created a window of opportunity in which surgery could be reconsidered with acceptable operative risk.

Furthermore, this report emphasizes the importance of reassessing surgical indications over time. In desmoid tumors, treatment response should not be evaluated solely through conventional RECIST criteria or volumetric changes. Instead, careful analysis of anatomical remodeling—particularly in critical dimensions relevant to surgical access—may be more clinically meaningful. In this case, pathological analysis confirmed marked tumor devitalization, with less than 10% residual viable desmoid cells, supporting a major treatment effect rather than a formal oncological downstaging. Finally, the case underscores the central role of multidisciplinary management in expert centers. The favorable outcome was the result of iterative decision-making involving medical oncologists, interventional radiologists, thoracic surgeons, and radiologists over several years. Such dynamic, longitudinal multidisciplinary evaluation is essential for managing rare and complex tumors such as intrathoracic desmoid tumors.

Although limited by its single-case nature and the relatively short postoperative follow-up period of 8 months, insufficient to reliably assess recurrence given the known unpredictable and potentially late recurrence pattern of desmoid tumors, this report provides novel, practice-relevant insight. It suggests that cryoablation may expand surgical options in selected patients and supports a paradigm in which interventional radiology techniques are integrated as complementary tools within a multidisciplinary therapeutic strategy.

Conclusions

PCA may represent a tumor downsizing strategy for large intrathoracic desmoid tumors initially considered unresectable. In this case, cryoablation was associated with both radiological tumor reduction and a marked pathological response, with less than 10% residual viable desmoid cells identified at final histological examination. This combined radiological tumor downsizing and a major pathological response facilitated reconsideration of surgical resection, ultimately allowing delayed en bloc R0 resection. These findings highlight the potential role of cryoablation in expanding surgical options within a multidisciplinary, personalized treatment strategy for this rare and challenging disease.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the CARE reporting checklist. Available at https://med.amegroups.com/article/view/10.21037/med-2026-1-0004/rc

Peer Review File: Available at https://med.amegroups.com/article/view/10.21037/med-2026-1-0004/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://med.amegroups.com/article/view/10.21037/med-2026-1-0004/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Declaration of Helsinki and its subsequent amendments. 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 editorial office of this journal.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Cazzato RL, Gantzer J, de Marini P, et al. Sporadic Desmoid Tumours: Systematic Review with Reflection on the Role of Cryoablation. Cardiovasc Intervent Radiol 2022;45:613-21. [Crossref] [PubMed]
2. Brener-Chaoul M, Cervantes-Gutiérrez Ó, Padilla-Longoria R, et al. Desmoid tumors: diagnostic and therapeutic considerations. Gac Med Mex 2020;156:439-45. [Crossref] [PubMed]
3. Mangla A, Agarwal N, Schwartz G. Desmoid Tumors: Current Perspective and Treatment. Curr Treat Options Oncol 2024;25:161-75. [Crossref] [PubMed]
4. National Comprehensive Cancer Network (NCCN). Soft Tissue Sarcoma. Version 1.2025. May 2, 2025. Available online: https://www.nccn.org/professionals/physician_gls/pdf/sarcoma.pdf
5. Kurtz JE, Buy X, Deschamps F, et al. CRYODESMO-O1: A prospective, open phase II study of cryoablation in desmoid tumour patients progressing after medical treatment. Eur J Cancer 2021;143:78-87. [Crossref] [PubMed]
6. Rosa AA, Carolina AP, Marta AV, et al. Desmoid Tumors-Experience from a Referral Center, Part 1: Multidisciplinary Review and Practical Recommendations. Cancers (Basel) 2025;17:3470. [Crossref] [PubMed]
7. Kasper B, Ströbel P, Hohenberger P. Desmoid tumors: clinical features and treatment options for advanced disease. Oncologist 2011;16:682-93. [Crossref] [PubMed]
8. Nieuwenhuis MH, Lefevre JH, Bülow S, et al. Family history, surgery, and APC mutation are risk factors for desmoid tumors in familial adenomatous polyposis: an international cohort study. Dis Colon Rectum 2011;54:1229-34. [Crossref] [PubMed]
9. Santti K, Ihalainen H, Rönty M, et al. Estrogen receptor beta expression correlates with proliferation in desmoid tumors. J Surg Oncol 2019;119:873-9. [Crossref] [PubMed]
10. Rastrelli M, Chiusole B, Cavallin F, et al. Desmoid Tumors in the Active Surveillance Era: Evaluation of Treatment Options and Pain Relief in a Single-Center Retrospective Analysis. J Pers Med 2023;13:1653. [Crossref] [PubMed]
11. Kasper B, Baldini EH, Bonvalot SDesmoid Tumor Working Group, et al. Current Management of Desmoid Tumors: A Review. JAMA Oncol 2024;10:1121-8.
12. Desmoid Tumor Working Group. The management of desmoid tumours: A joint global consensus-based guideline approach for adult and paediatric patients. European Journal of Cancer 2020;127:96-107.
13. Bodard S, Marcelin C, Kastler A, et al. Safety and efficacy of cryoablation of soft-tissue tumours: a systematic review. Br J Radiol 2025;98:861-74. [Crossref] [PubMed]
14. Mandel JE, Kim D, Yarmohammadi H, et al. Percutaneous Cryoablation Provides Disease Control for Extra-Abdominal Desmoid-Type Fibromatosis Comparable with Surgical Resection. Ann Surg Oncol 2022;29:640-8. [Crossref] [PubMed]
15. Timbergen MJM, Schut AW, Grünhagen DJ, et al. Active surveillance in desmoid-type fibromatosis: A systematic literature review. Eur J Cancer 2020;137:18-29. [Crossref] [PubMed]
16. Borghi A, Gronchi A. Desmoid tumours (extra-abdominal), a surgeon's nightmare. Bone Joint J 2023;105-B:729-34. [Crossref] [PubMed]
17. Bonvalot S, Eldweny H, Haddad V, et al. Extra-abdominal primary fibromatosis: Aggressive management could be avoided in a subgroup of patients. Eur J Surg Oncol 2008;34:462-8. [Crossref] [PubMed]
18. Colak C, Hull C, Simpfendorfer C, et al. Extra-abdominal desmoid fibromatosis: Cryoablation versus traditional therapies. Clin Imaging 2022;88:9-16. [Crossref] [PubMed]
19. de Bruyns A, Li H, MacNeil A, et al. Evolving Practice Patterns Over Two Decades (1993-2013) in the Management of Desmoid-type Fibromatosis in British Columbia. Clinical Oncology (Royal College of Radiologists (Great Britain)) 2020;32:e102-10.
20. Vora BMK, Munk PL, Somasundaram N, et al. Cryotherapy in extra-abdominal desmoid tumors: A systematic review and meta-analysis. PLoS One 2021;16:e0261657. [Crossref] [PubMed]