Recurrent inverted papilloma coexisted with skull base lymphoma: A case report

Figure 1 Magnetic resonance imaging of the head with contrast showed a heterogeneously enhanced mass involving the right nasal cavity (asterisk), orbital cavity, and bilateral frontal sinus with intracranial invasion (cross), and another lobulated fluid collection, suspected as a mucocele, at the right ethmoid cells (double-cross). A: Coronal section; B: Sagittal section; C: Axial section of the magnetic resonance imaging, which showed the orbital cavity invaded and compressed by the lesion (double-cross) from the medial side; D: Bilateral frontal sinuses that were involved by the lesion.

Figure 2 Histological examinations. A and B: Hematoxylin and eosin (H/E, 20 ×) sections showed an inverted papilloma with an inward growth pattern, which is composed of the proliferating columnar and squamous epithelial cells; C: H/E (100 ×) section showed medium to large tumor cells with oval to round shape, occasional poly-lobulated, vesicular nuclei containing fine chromatin and several nuclear membranes, with bound nucleoli infiltrating within the nasal stroma and brain tissue; D: Immunohistochemically, the tumor cells were positive for Bcl-2; E: Immunohistochemically, the tumor cells were negative for Bcl-6; F: The Ki-67 index was approximately 90%-95%.