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Inflammatory pseudotumor of the pineal region: First reported case
Ping-Ding Kuang1, Qing-Hai Li1, Zi-Yu Liu2
1Department of Radiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China.
Insights
This study details the first reported case of a central nervous system (CNS) inflammatory pseudotumor in the pineal region. Neuroimaging and pathological findings confirmed the rare diagnosis, leading to successful surgical resection and a positive prognosis.
Area of Science:
- Neurology
- Pathology
- Oncology
Background:
- Central nervous system (CNS) inflammatory pseudotumors are exceptionally rare occurrences.
- Inflammatory pseudotumors in the pineal region are particularly uncommon, with this study presenting the first documented case.
Purpose of the Study:
- To report the initial case of an inflammatory pseudotumor in the pineal region.
- To describe the comprehensive neuroimaging, morphological, and immunohistochemical characteristics of this rare CNS lesion.
Main Methods:
- Magnetic resonance imaging (MRI) was utilized for detailed visualization of the pineal region mass and associated hydrocephalus.
- Histopathological examination of the resected lesion was performed, including morphological analysis and extensive immunohistochemical staining.
- Immunohistochemistry was employed to identify cell types and markers, including CD138, glial fibrillary acidic protein, S-100, neurofilament, Ki-67, CD3, CD43, CD20, CD79A, and immunoglobulin light chains (κ and λ).
Main Results:
- MRI revealed a homogeneously-enhanced mass in the pineal region causing obstructive hydrocephalus.
- Pathology showed a lesion composed of spindled cells in a collagenous background with significant lymphocytic, plasma cell, and histiocyte infiltrates.
- Immunohistochemistry confirmed immunopositivity for CD138, with T-cells (CD3+, CD43+), B-cells (CD20+, CD79A+), and polytypic plasma cells. The Ki-67 labeling index was low (<5%), and cells were immunonegative for glial and neural markers.
Conclusions:
- The combined neuroimaging and detailed histopathological/immunohistochemical findings supported the diagnosis of a pineal region inflammatory pseudotumor.
- Surgical resection was successfully performed, and the patient achieved a favorable prognosis, highlighting the importance of accurate diagnosis for effective management.
Abstract:
Inflammatory pseudotumors originating in the central nervous system (CNS) are quite rare. To the best of our knowledge, the present study reports the first case of a inflammatory pseudotumor that developed in the pineal region, and describes the neuroimaging, morphological and immunohistochemical findings. A 53-year-old male presented with hearing loss that had been apparent for 1 year and blurred vision that had persisted for 10 months. Magnetic resonance imaging (MRI) demonstrated a homogeneously-enhanced mass in the pineal region and obstructive hydrocephalus. A pathological examination revealed that the lesion was comprised predominantly of spindled cells in a collagenous background, with dense infiltrates of small lymphocytes, plasma cells and uninucleated histiocytes. Immunopositivity for cluster of differentiation (CD)138 was noted. Immunohistochemical staining showed that the cells were immunonegative for glial fibrillary acidic protein, S-100, placental alkaline phosphatase, neurofilament and Pit-Oct-Unc class 5 homeobox 1. The Ki-67 labeling index was <5%. The lymphocytic infiltrates consisted of CD3- and CD43-positive T-cells, and CD20- and CD79A-positive B-cells. Plasma cells displayed polytypic reactivity for immunoglobulin κ and λ light chains. Based on the MRI and the morphological and immunohistochemical analysis, a diagnosis of an inflammatory pseudotumor was formed. The patient underwent a surgical resection of the tumor and currently has a good prognosis.
