case_images: PMC10634224_01
case_images: In October 2019, an axial paranasal sinus MRI on first presentation (A,B, arrows) demonstrated mucosal swelling of the left nasal cavity with low signal on T1WI and high signal on T2WI. The mucosa of bilateral maxillary sinus, ethmoid sinus and left frontal sinus were thickened, especially the left maxillary sinus with a soft tissue mass, which were considered to be inflammation. In May 2020, brain MRI (C,D) revealed abnormal signal in the left frontal lobe showing mixed signal on T1WI and heterogeneous high signal on T2WI, causing mild peritumoral edema, mild compression of the anterior horn of the left ventricle and slight midline shift. Consequently, lymphoma involvement with hemorrhage was considered. In November 2021, preoperative brain MRI (E,F) showed an irregular mass in the left frontal lobe, with mixed intensity signal on T1WI and heterogeneous high signal on T2-FLAIR. After enhancement, axial (G, arrow) and sagittal (H, arrow) brain MRI showed the mass was wreath-like enhancement. The left anterior horn of the ventricle was compressed, the midline structure was obviously shifted to the right, and the left optic tract and anterior commissure were compressed. The cisterna of ventricles enlarged and the cerebral sulci deepened.
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case_images: Cranial magnetic resonance imaging (MRI) demonstrated swelling of the left nasal cavity mucosa with inflammation in the paranasal sinus, leading to an endoscopy-guided biopsy (Figures 1A,B). In May 2020, the patient experienced a possible CNS relapse, as indicated by MRI findings (Figures 1C,D), promoting treatment with three cycles of anti-PD1 therapy in combination with high-dose methotrexate (MTX). Weighted imaging. Wreath-like enhancement surrounded by lamellar edema, midline shift, and ventricle dilation was observed, suggesting possible lymphoma progression and brain herniation (Figures 1E-H).
case_images: Left nasal cavity biopsy (A,B) demonstrated diffuse infiltration of atypical cells with coarse chromatin, prominent nucleoli by H&E-stain. Immunohistochemical stains (C to H) revealed the tumor cells expressing cytoplasmic CD3 (C), CD30, CD56 (D), TIA-1 (E) and MUM-1 were positive with Ki-67 (F) index of >40%, but negative for the rest of the T-cell markers including CD5 (G) and ALK/P80 (H) Post-operative pathology (I) showed necrosis of the left frontal brain tissue and hyperplasia of histocytes without neoplastic cells.
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case_images: TIA-1 and MUM-1, with Ki-67 index of >40% (Figures 2A-H). These findings confirmed the diagnosis of extranodal ENKTL. Emergency decompressive craniectomy was performed, and a pathological examination of the biopsy specimen demonstrated diffuse necrosis of the left frontal lobe without evidence of lymphoma involvement (Figure 2I).
case_images: PET/CT revealed thickened mucosa of nasal cavity and ethmoid sinus, which extends to the subcutaneous tissue and part of left orbit, with a maximum standardized uptake value (SUVmax) of 14.25. Several enlarged lymph nodes were also noted in left preauricular, parotid ande cervical regions, with a SUVmax of 14.50.
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case_images: Positron emission tomography/computed tomography (PET/CT) showed tumor extension into the nasal cavity, ethmoidal sinus, left orbit, and surrounding lymph nodes (Figure 3).
case_images: The timeline of clinical courses of the ENKTL patient with brain herniation due to severe radiation necrosis, which were assessed by both MRI and biopsy. ENKTL, extranodal NK/T cell lymphoma; CNS, central niveous system; MTX, methotrexate; ASCT, autologous stem cell transplantation.
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case_images: The timeline of this case was summarized in (Figure 4).