Dear Editor,

We are writing to express my appreciation for the groundbreaking article titled “Frequency and Imaging Features of Adjacent Osseous Changes of Salivary Gland Carcinomas in the Head and Neck Region” by Horiuchi and Shimono et al., which has recently been published in Neuroradiology [1]. This study presents a useful finding that has not been previously reported, highlighting the association between osseous sclerosis adjacent to salivary gland tumors and the histological subtype of adenoid cystic carcinoma (ACC). It is a serendipitous finding in head and neck tumors, which often pose challenges in qualitative diagnosis. We believe many readers have already recognized the usefulness of this study and its implications.

However, we would like to draw attention to one important consideration after reading the article. That is, the fact that sclerosis in adjacent bone does not always suggest tumor invasion. In their study, the authors evaluated osseous changes solely based on imaging and did not establish a histopathological diagnosis, as the authors have already noted in the discussion section enough.

We indeed encounter some cases of histopathologically proven bone infiltration that cause osteosclerosis; however, there are other cases in which no histopathological infiltration was found and the bone margins were negative under resection of the surrounding bone without any preoperative treatment. It should be noted that the fact that this finding does not always match the pathological invasion of the tumor, which may be different from other head and neck tumors, such as olfactory neuroblastoma, where osteosclerosis is likely to indicate invasion [2].

Although the presence of peritumoral osteosclerotic change is a very valuable and compelling sign of suspicion for ACC, evaluation of tumor spread, i.e., T-staging, requires comprehensive use of careful imaging evaluation with a variety of MRI sequences or with FDG accumulation. Determination of imaging criteria for considering bone invasion or, conversely, for downstaging disease requires further case accumulation.

The bottom line is, we hope that more radiologists will utilize this valuable article, enhance the quality of their qualitative diagnoses rather than T staging, and ensure the proper utilization of this study. We extend our gratitude to the authors for their contribution to the field of neuroradiology.