Abstract 6308: Adhesive capsulitis vs. metastasis: Comparative frequency in oncology patients with hip pain

Abstract Background: Adhesive capsulitis (AC) is defined as the gradual, progressive loss of range of joint motion due to inflammation, adhesions, and capsular thickening. Shoulder AC is well established with a prevalence of 2-5% in the general population, but the prevalence of hip AC remains unknown, likely due to underdiagnosis. Existing literature suggests shared risk factors between shoulder and hip AC—including diabetes, thyroid disease, trauma, and surgery. In addition, while AC has been studied in the general population, its prevalence has not been extensively evaluated in the oncologic population. Oncologic patients with hip pain frequently undergo contrast-enhanced MRI to exclude metastasis, yet the relative frequency of tumor infiltration versus adhesive capsulitis remains unclear. Prior (few) studies have only used non-contrast, fat-suppressed T2W MRIs, making it challenging to differentiate the capsule from the iliofemoral ligament clearly. CEMR incorporates non-contrast sequences, allowing assessment of key AC features—including capsular and iliofemoral ligament thickening or enhancement, as well as preferential fluid pooling in the posterior recess or iliopsoas bursa. Purpose: To determine the frequency of AC in patients with known primary malignancy undergoing CEMR of hip joint at a tertiary care academic center. Methods: In this cross-sectional retrospective analysis, from 01/2021 to 01/2025, CEMR studies of hip joints were identified, yielding 57 eligible examinations. Adult patients (>18) with a known primary malignancy were included. Exclusions comprised non-contrast MRIs, absence of confirmed malignancy, significant artifacts, recent trauma, or known inflammatory or infectious conditions. Prospectively, reports were generated by fellowship-trained MSK radiologists in our center. Studies were subsequently re-reviewed by an additional radiologist to evaluate for features of AC, including capsular thickening, capsular enhancement, fluid pooling in synovial recesses, and/or presence of tumor lesions in the imaged hips. Results: Preliminary analysis yields AC in 9/57(16%) cases. 48/57 (84%) MRIs demonstrated a malignant lesion, non-AC condition. Further analyses will assess how often hip adhesive capsulitis occurs across age groups, genders, and malignancy types. Quantitative measures of capsular thickening, enhancement, and joint recess distention will help refine characterization of these imaging findings. Conclusion: Though occurring at a smaller frequency, AC can present as hip pain in patients with known primary malignancy. Recognizing this pattern can help clinicians direct appropriate management and prevent unnecessary concern for metastatic disease. Citation Format: Laasya Madana, Avneesh Chhabra, Alireza Eajazi. Adhesive capsulitis vs. metastasis: Comparative frequency in oncology patients with hip pain [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 6308.