Primary central nervous system lymphoma and 5-aminolevulinic acid

Abstract

Background: Despite surgical resection of primary central nervous system lymphomas (PCNSL) having been always discouraged, recent evidence supports that it might improve prognosis in this patient population. Five- aminolevulinic acid-derived fluorescence is widely used for the resection of malignant gliomas, but its role in PCNSL surgery remains unclear.

Case description: We present two patients with a solitary solid intraparenchymal mass. As high-grade glioma leaded the list of differential diagnosis (other possibilities were metastasis, abscess, and PCNSL), a five- aminolevulinic acid-guided complete resection (with strong fluorescence in both cases) was done. Surgery was uneventfully carried on with complete resection until five-aminolevulinic acid-induced fluorescence was no longer evident. After surgery, patients have no neurological deficits and had good recovery. Pathological examination revealed that both tumors were PCNSL. Adjuvant radiotherapy and chemotherapy were started. After 1 year of follow-up, patients have good evolution and have no recurrences.

Conclusion: These cases add to the growing literature which shows that surgery might play an important role in the management of PCNSL with an accessible and single lesion. Five-aminolevulinic acid could also be a useful tool to achieve complete resection and improve prognosis in this group of patients.

Keywords: 5-Aminolevulinic acid; Brain injuries; Lymphoma; Neuro-oncology; Neurosurgery.

Figure 1:

The images a, b, and c correspond to the patient 1. The images d, e, and f correspond to the patient 2. In both cases, we can appreciate a single intra-axial lesion in the right frontal lobe, prominently hypointense in T1 sequences (a and d) and hyperintense in T2 sequences (b and e). It shows intense contrast enhancement with hypocaptant center of cystic/necrotic aspect and is surrounded by a large halo of edema with vasogenic characteristics (c and f).

Figure 2:

The images a and b correspond to the patient 1. The images c, d, and e correspond to the patient 2. Diffusion-weighted image demonstrate a clear rim of restricted diffusion in its solid marginal components: periphery of the lesion evince hyperintensity on diffusion- weighted imaging (a and c) and very low values on apparent diffusion coefficient map (b and d). In the perfusion study of the patient 2 (e), the peripheral region of the lesion manifests a slight increase in relative cerebral blood volume about 1.6 respect to the healthy contralateral white matter.

Figure 3:

All images belong to the patient 1. These images correspond to the surgical site (a and b) and the tumor resection (c and d). We can appreciate strong red fluorescence under blue light illumination (OPMI/Pentero, Carl Zeiss, Oberkochen, Germany).

Figure 4:

Postoperative magnetic resonance image (contrast- enhanced T1-weighted images). Total resection of the tumor was achieved in the patient 1 (a). The patient 2 present milimetric remains in the surgical site (b).

Figure 5:

All images belong to the patient 2. Paraffin section with immunoperoxidase technique ×10. Neoplastic cells express CD20 (a), BCL2 (b), BCL6 (c), MUM1 (d), and MYC (e). Ki-67 proliferation index is high (f).