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

Abstract

Background: Inverted papilloma is an uncommon neoplasm in the nasal cavity. It is a histologically benign tumor, but has a high recurrence and local invasion rate. In addition, nasal or skull base lymphoma is another rare neoplasm. The coexistence of these two tumors in one case makes the diagnosis and related treatment difficult.

Case summary: We report a case of an immunocompetent patient, who had a history of inverted papilloma 20 years ago. The patient presented with an infiltrated mass lesion in the nasal cavity with extension to the frontal base. The repeated biopsies revealed inverted papilloma without any malignant transformation. After the patient underwent a frontobasal craniotomy with total tumor excision, the final pathological examination revealed nasal inverted papilloma coexisting with diffuse large B-cell lymphoma of the skull base.

Conclusion: Based on this case report, while managing a case of an aggressive recurrent inverted papilloma, not only squamous cell carcinoma transformation, but also other invasive malignancy, such as lymphoma, should be considered.

Keywords: Case report; Coexisting tumors; Inverted papilloma; Primary central nervous system lymphoma; Skull base; Squamous cell carcinoma.

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%.