Benign neck masses showing restricted diffusion: Is there a histological basis for discordant behavior?

Abstract

Diffusion weighted imaging (DWI) evolved as a complementary tool to morphologic imaging by offering additional functional information about lesions. Although the technique utilizes movement of water molecules to characterize biological tissues in terms of their cellularity, there are other factors related to the histological constitution of lesions which can have a significant bearing on DWI. Benign lesions with atypical histology including presence of lymphoid stroma, inherently increased cellularity or abundant extracellular collagen can impede movement of water molecules similar to malignant tissues and thereby, show restricted diffusion. Knowledge of these atypical entities while interpreting DWI in clinical practice can avoid potential misdiagnosis. This review aims to present an imaging spectrum of such benign neck masses which, owing to their distinct histology, can show discordant behavior on DWI.

Differentiation of Benign From Malignant Sinonasal Masses Using Diffusion Weighted Imaging and Dynamic Contrast Enhanced Magnetic Resonance Imaging

“…6 In case of giant cell granuloma, restricted diffusion could be due to hemorrhage and extensive fibrous stroma. Das et al 7 attributed diffusion restriction in hemangiopericytoma to its hypercellularity and compact cellular arrangement.…”

Cervical lymphadenopathy in tularemia: the role of diffusion-weighted magnetic resonance imaging in differentiating lymphadenopathies due to metastatic tumors

“…It is based on diffusion properties of water protons in biologic tissues, including the diffusion of molecules in extracellular or intracellular spaces as well as in cell membranes. There were numerous reports of DW-MRI characterization of malign, and benign lymph nodes might be completed without the need for invasive procedures [5][6][7][8]. The aim of this study is to evaluate the DW-MRI features of lymph node involvement due to tularemia and metastatic tumors in the head and neck region and to show the similarities and differences between them.…”

Restricted diffusion in benign intracranial neoplasms: a narrative review

“…It is based on free, constant, and random movement of intra-and extracellular water molecules (Brownian motion). In tissue, the motion of water molecules can be decreased (restricted diffusion) or increased (free diffusion) depending on tissue type, intra-and extracellular interactions, or certain pathological causes [1].…”

“…While interpreting DWI, it is important for the radiologist to be aware of various histological attributes like matrix composition, which can have a significant influence on diffusion characteristics. Some pathological entities, despite being benign, can have inherently increased cellularity and hence can mimic malignant lesions on DWI [1]. Anticipation of such atypicality in benign CNS lesions can reduce the possibility of potential misdiagnosis, thereby improving the diagnostic accuracy [1].…”

“…Some pathological entities, despite being benign, can have inherently increased cellularity and hence can mimic malignant lesions on DWI [1]. Anticipation of such atypicality in benign CNS lesions can reduce the possibility of potential misdiagnosis, thereby improving the diagnostic accuracy [1].…”