Background Angiectatic nasal polyps with pleomorphism (PANP) are rare benign lesions of nose and paranasal sinuses. Clinical manifestation includes nose obstruction, bleeding and headache. The demonstrating bone-damaged lesion by imaging as well as the enlarged and pleomorphic stromal cells with nuclear atypia by morphology simulate a malignant process, which may be misdiagnosed. The aim of the present study is to generalise the features of PANP in case of potential clinical and pathological pitfall of diagnosis.
Methods Thirteen patients diagnosed as PANP were retrospectively analyzed in the Pathology Department of Beijing Tongren Hospital Affiliated to Capital Medical University from August 2014 to December 2019. Immunohistochemical staining with CD34, CK, Vim, Calponin, Ki67,Bcl-2, and STAT-6 was performed with envision-two steps method.
Results PANP is a benign tumor presenting with gross variegated tan to gray soft fleshy tissue with foci of obvious hemorrhage and necrosis. The imaging shows internal heterogeneous hyperintensity with a peripheral hypointense rim while postcontrast images display a strong nodular and patchy enhancement. Vimentin (Vim) stain was consistently positive , while negative for CD34, STAT-6 and Bcl-2 (focal positive in two cases). Calponin and CK stain was positive in nine cases, respectively .
Conclusions PANP is a clinically rare tumor which may stimulate malignancy lesion. Recognizing of characteristic features in these thirteen patients would be beneficial to avoid misdiagnosis and unnecessary aggressive treatment.