ARRS 2022 Abstracts


E1035. Mimicking Malignancy: A Head to Toe Review of Benign Soft Tissue Pseudomasses
  1. Eric Pang; Mallinckrodt Institute of Radiology
  2. Eric Fischer; Mallinckrodt Institute of Radiology
  3. Jonathan Baker; Mallinckrodt Institute of Radiology
Soft tissue masses are commonly encountered by patients and their physicians in clinical practice. While the vast majority are benign, some may mimic sarcomas due to their varied imaging appearance. A multimodality imaging approach is often complementary, especially when radiologists encounter equivocal or complex cases. To that end, this exhibit aims to familiarize radiologists with these lesions to prevent misdiagnosis which can lead to unnecessary interventions or delay appropriate care for benign lesions.

Educational Goals / Teaching Points
The exhibit will review the imaging evaluation of common and important pseudomasses through a systematic case-based approach. Discussion will include the appropriate uses and limitations of radiography, ultrasound, CT, and MRI; the importance of anatomic location, calcification pattern, and contrast enhancement for differential diagnosis; and the imaging features of common entities masquerading as sarcoma.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
This exhibit will focus on notable inflammatory/reactive (e.g. adventitial bursitis, elastofibroma dorsi, pigmented villonodular synovitis, synovial pannus, tumoral calcinosis), and post-traumatic (e.g. calcific myonecrosis, chronic hematoma, degloving injuries, retracted muscle/tendon tears) pseudomasses. Lesions will be categorized according to common anatomic locations as well as anatomic site of involvement (muscle, tendon, fascia, bursae, synovium, and joint space). Each case will discuss pertinent clinical features, including patient demographics, lesion chronicity, physical examination findings, and underlying pathophysiology. These features will be correlated with specific imaging characteristics, including but not limited to, calcification pattern, contrast enhancement, and lesion composition (cystic, fat, fibrous, etc.). Pseudomasses will be juxtaposed with selected examples of biopsy proven sarcomas to highlight distinguishable features. These cases will illustrate the common limitations and pitfalls within each imaging modality that may lead to misdiagnosis.

Radiologists should be able to recognize the varied but characteristic imaging features of clinically significant soft tissue pseudomasses on multiple imaging modalities. Familiarity with these entities will allow radiologists to make an accurate diagnosis and forestall unnecessary biopsy procedures and patient anxiety.