Primary Site Identification of Soft-Tissue Mass: Things to Know in MRI Assessment

Abstract

The spectrum of soft-tissue mass is varied, including neoplastic and nonneoplastic/inflammatory lesions. However, soft-tissue tumors have similar imaging findings and, therefore, the diagnosis of soft-tissue mass is challenging. Although careful assessment of the internal characteristics on imaging can often narrow the differential diagnoses, the differential diagnosis may be out of the question if identification of the soft-tissue mass origin is missed. The purpose of this article is to review the imaging findings and the essential anatomy to identify the primary site of the soft-tissue mass, and discuss the associated potential pitfalls. In order not to fall into a pitfall, recognition of characteristic imaging findings indicating the origin of the soft-tissue mass and anatomical knowledge of the normal tissue distribution are necessary. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY STAGE: 3.

Keywords: Magnetic resonance imaging (MRI) is a powerful medical imaging modality that has been used extensively in the evaluation of soft-tissue mass. MRI findings of the soft-tissue mass in conjunction with clinical information (clinical history, physical evaluation, age, etc.) can allow a suspected diagnosis or a reasonable differential diagnosis. However, misinterpretation of the soft-tissue mass origin based on the imaging findings can lead to a deeply misguided diagnosis. This article aims to systematically review the imaging findings and the essential anatomy to identify the primary site of the soft-tissue mass. We describe and illustrate the important diagnostic clues and the essential anatomy to determine the origin of the soft-tissue mass. In addition, the associated potential pitfalls are discussed.; SOFT-TISSUE TUMORS are a highly heterogeneous/diverse group of tumors, and the number is quite large. On the other hand, there are also a wide variety of nonneoplastic lesions forming soft-tissue masses, and many of them have a clinical presentation simulating that of a soft-tissue tumor. In addition to reasons such as these, the overlapping of their imaging features often makes diagnosis of soft-tissue mass challenging for radiologists.; digital radiography; magnetic resonance imaging; primary site; soft tissue mass; soft tissue tumor.