Cell-Block cytology in diagnosis of primary central nervous system lymphoma: A case report

Abstract

Introduction: Primary Central Nervous System Lymphoma (PCNSL) remains a diagnostic challenge due to the variable clinical manifestations. Liquid biopsies, particularly those involving cell-free DNA (cfDNA) from plasma, are rapidly emerging as important and minimally invasive adjuncts to traditional biopsies. However, conventional pathology may be still essential to obtain a diagnosis.

Patient concerns: A 56-year-old woman presented with a progressive headache, dizziness, blurred vision, and lower limbs weakness with dysesthesia. Atypical clinical and radiological presentations, previous empirical treatment in another hospital, together with the patient's refusal to stereotactic brain biopsy made it challenging to diagnose. Her status deteriorated continuously during hospitalization.

Diagnosis: Lumber punctual was performed, and CSF cytological analysis revealed malignancy cells with a high nuclear-cytoplasmic ratio. However, these cells were too loose to perform immunohistochemical stains. Genetic aberrations detections with CSF and peripheral blood sample were also inconclusive. We made a "cell-block" using the sedimentary cells collected from CSF collected through multiple aspirations via an Omaya reservoir. We further performed cytopathological and immunohistochemical analysis using this "cell-block," which finally confirmed the diagnosis of diffuse large-B cell PCNSL.

Interventions: Intracranial chemotherapy began afterwards (MTX 15 mg and dexamethasone 5 mg, twice per weeks).

Outcomes: Unfortunately, this patient was dead 2 weeks later due to severe myelosuppression and secondary septic shock.

Conclusion: We provided "cell-block" method, which collects cell components from large amount of CSF for cytology and immunohistochemical analysis. "Cell-block" cytology can be an alternative diagnostic method in diagnosis of PCNSL.

Figure 1

FDG-PET performed 4 months before this presentation showed that FDG uptake increased in the callosal area with a maximal SUV of 16.5 (panel A), and the area abutting the fourth ventricle with a maximal SUV of 16.2 (panel B).

Figure 2

Spinal MRI revealed diffuse thickening of the dura matter and multiple tuberous lesion, which were enhanced after gadolinium administration (panel A: T1-weighted, panel B: T2-weighted, panel C: gadolinium contrast enhanced T1-weighted).

Figure 3

Cranial MRI showed an isointense nodular lesion in the pineal region on T1-weighted (panel A) and T2-weighted phases (panel B), which lead to mild hydrocephalus. Sagittal view of T2-weighted MRI also revealed a hyperintense lesion in the dorsal medulla (panel C, yellow arrowhead). Both two lesions were enhanced after gadolinium enhancement.

Figure 4

Microscopy of the “cell-block” revealed numerous malignant cells with a high nuclear-cytoplasmic ratio, which further confirmed the diagnosis of large B cell lymphoma by immunohistochemical stains (∗40∗10).