Cryo-surgery for symptomatic extra-abdominal desmoids. A proof of concept study.

BACKGROUND AND OBJECTIVE: Extra abdominal desmoid tumors are rare, highly aggressive, and invasive benign soft tissue tumors. Current treatment modalities show high levels of recurrence and comorbidities. Cryo-surgery as an alternative was subsequently investigated. METHODS: In this retrospective, single center study 11 patients showing symptomatic tumors were treated with individualized cryo-surgery. Treatment protocol included preoperative planning using computer rendered 3D models, intraoperative navigation and execution using cone beam guidance, and postoperative magnetic resonance imaging image analysis using a gaussian mixture model software. Subjective outcomes were reported using Short Form Health Survey (SF-36) questionnaires. RESULTS: Sixteen ablations were performed, each demonstrating a complete match with the determined preoperative plan and model. A total of 9/11 (82%) of patients showed improvements in symptoms and a reduction in tumor volume while 2/11 (18%) did not. Average reduction in tumor volume and viable segments were 36.7% (p = 0.0397) and 63.3% (p = 0.0477), respectively. Mild complications according to the SIR Adverse Event Classification Guidelines were experienced in 3/16 (19%) ablations. SF-36 scores showed a statistically significant improvement (p = 0.0194) in the mental health category and a nonsignificant (p = 0.8071) improvement in the physical health category. CONCLUSION: Cryo-surgery using the three-phase protocol as described may improve the overall outcome of future ablation procedures.

Intraarticular Inflammatory Myofibroblastic Tumor of the Left Knee With ALK-CARS Fusion Detected With Archer Fusionplex Sarcoma NGS Panel: Case Report and Literature Review.

Inflammatory myofibroblastic tumor (IMT) is a lesion of intermediate biological potential with local recurrences and rare metastases found in multiple anatomical locations. We present a case of a pure intraarticular IMT of the knee, a location that has not been previously documented, with genetic confirmation of ALK-CARS fusion detected with next-generation sequencing. A 20-year-old healthy male was admitted to the orthopedic oncology department due to several months of pain and restriction in movement of his left knee. On magnetic resonance imaging, multiple intraarticular nodular lesions were seen. The patient underwent 2 synovectomies within the course of 1 year. The initial biopsy was interpreted as nodular fasciitis. The second biopsy revealed exuberant tissue displaying compact fascicles of spindle cells intermixed with myxoid areas in a background of inflammatory cells, highly suggestive for IMT. Due to the unusual intraarticular location, equivocal ALK immunostaining and the differential diagnosis with nodular fasciitis, we performed targeted next-generation sequencing using Archer FusionPlex Sarcoma panel, which can identify multiple fusions in a single assay. An ALK-CARS fusion was found, supporting the diagnosis of IMT. This report emphasizes the added value of broad molecular analysis in cases with unusual clinical presentation, equivocal immunohistochemistry, and a wide differential diagnosis.