PMC8149129_01
A. Duramater was diffusely infiltrated by sheets of small neoplastic lymphocytes (H&E, 100x). B. Remnants of colonizes lymphoid follicles could be seen (H&E, 200x). C. Most of the cells had clear cytoplasm, giving a monocytoid appearance (H&E, 400x). D. Those cells showed strong and diffuse CD20 staining (CD20, 200x). E. CD21 antibody highlighted the residual meshwork of follicular dendritic cells (CD21, 200x). F. The proliferating index was low, with weak staining in less than 5% of the cells (Ki-67, 400x)
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Immunohistochemistry demonstrated positivity for CD20 and Bcl-2, with residual meshwork of follicular dendritic cells highlighted by CD23 and a low proliferative index, consistent with the diagnosis of an extranodal marginal zone lymphoma (Fig. 1).
Treatment planning with 3D technique and dose distribution between 2100 and 3218.4 cGy
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The patient was then referred to our institution where it was decided to deliver adjuvant conformal radiotherapy with a dose of 21 Gy in 14 fractions to the whole brain and a boost of 9 Gy in 6 fractions to the tumor bed, completing a total dose of 30 Gy delivered in 20 fractions of 1.5 Gy (Fig. 2).
RM of the brain after 5 years of irradiation exhibiting good local control of the disease and no sign of recurrence
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Patient kept follow-up visits every 6 months with cranial MRI during the first year and annually after that, with no evidence of disease recurrence after a follow-up time of 7 years (Fig. 3).
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Treatment planning with IMRT technique and dose distribution between 2100 and 3245.6 cGy
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It was decided to deliver adjuvant intensity-modulated radiotherapy (IMRT with a dose of 21 Gy in 14 fractions to the whole brain and a boost of 9 Gy in 6 fractions to the tumor bed, completing a total dose of 30 Gy delivered in 20 fractions of 1.5 Gy (Fig. 4).
RM of the brain after 3 years of irradiation with good local control of the disease and no sign of recurrence
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A complete response was achieved with no signs of disease recurrence, after a follow-up time of 6 years and 9 months (Fig. 5).