Unmasking hypertrophic pachymeningitis radiologically: A case series of diverse etiologies
Ishani Nayyar, Sahil Gupta, Sudhansu Sekhar Mohanty, Sangram Panda, Basanta Manjari Swain, Somya GuptaAbstract:
Context:
Hypertrophic pachymeningitis (HP) is an uncommon but clinically significant condition characterized by focal or diffuse dural thickening with diverse etiologies, including infectious, inflammatory, neoplastic, and idiopathic causes. Differentiation among these entities remains challenging and often requires histopathological confirmation. However, characteristic imaging patterns on magnetic resonance imaging (MRI) can aid in narrowing the differential diagnosis and guiding management.
Aims:
To evaluate MRI characteristics of HP and identify imaging patterns correlating with underlying etiologies, thereby improving diagnostic accuracy and reducing reliance on invasive procedures.
Settings and Design:
It was a retrospective descriptive study, conducted over a period of 6 months, from April 1, 2025, to October 1, 2025, at a tertiary center.
Materials and Methods:
Patients demonstrating enhancing dural thickening on MRI suggestive of HP were included. Clinical details, laboratory parameters, including cerebrospinal fluid analysis and relevant serology, and histopathological findings (where available) were reviewed. MRI assessment focused on the distribution, morphology, and enhancement characteristics of dural thickening.
Statistical Analysis Used:
Descriptive statistics were applied. Frequencies and percentages were used to summarize etiologies, patterns of thickening (focal/diffuse), morphology (smooth/irregular), and enhancement (homogeneous/heterogeneous). Correlation with underlying etiologies was assessed descriptively.
Results:
The study found that infectious causes, predominantly tuberculosis, constituted the majority (46.6%) of cases. Focal dural thickening was more common (73.3%) compared to diffuse involvement (26.6%). Heterogeneous enhancement patterns predominated (80%), particularly in infectious and neoplastic etiologies, whereas homogeneous enhancement was more frequently associated with inflammatory and reactive conditions.
Conclusions:
Focal, irregular, heterogeneously enhancing lesions favor infectious or neoplastic etiologies, while diffuse, smooth, homogeneous thickening suggests inflammatory or reactive causes. MRI-based pattern recognition is a valuable noninvasive tool that aids diagnosis and guides management.