HPV-associated squamous cell carcinoma in situ arising from urethral caruncle: A case of the unusual occurrence in the common urogenital lesion.

INTRODUCTION AND

IMPORTANCE

Urethral caruncle is one of the most prevalent urethral inflammatory disease in postmenopausal females. Although urethral caruncle is neither neoplastic nor preneoplastic, there have been rare reports of malignant neoplasm arising from them. Furthermore, none of them revealed association between urethral caruncle lesion and HPV (human papilloma virus) infection.

CASE PRESENTATION: We herein report a case of an 80-year-old female with squamous cell carcinoma in situ arising from the urethral caruncle, which was found to be associated with HPV infection. The 1.5 cm-sized mass located at posterior aspect of urethral meatus, was clinically suspected urethral caruncle.

CLINICAL DISCUSSION: After caruncle excision was performed, histopathological result demonstrates severe squamous dysplasia with koilocytic atypia, involving the whole thickness of squamous epithelium. No invasive tumour cell was identified, consistent with squamous cell carcinoma in situ. The lesion showed block positivity in p16 immunohistochemical staining, which is the surrogate marker for the cytopathic incorporation of human papilloma virus. In the following molecular study, viral expression of HPV was confirmed by real time PCR with detection of high-risk HPV subtype 39.

CONCLUSION

Squamous cell carcinoma originating from a urethral caruncle is an exceptionally uncommon occurrence. A comprehensive review on the English-written literature yielded only three previously documented case reports.