Squamous cell papilloma at the urethral meatus

Dear Editor,

Squamous cell papilloma in the urethra is a rare benign tumor and is usually reported in middle-aged and older women.1 It has never been documented in children. It is difficult to distinguish squamous papilloma from condylomata acuminatum and verrucous carcinoma because of their morphological overlap.2 Here, we report a rare case of a young child with squamous papilloma of the urethral meatus. Informed consent was obtained from the patient’s parents.

A 3-year-old boy was admitted to West China Hospital, Sichuan University (Chengdu, China), after the detection of a neoplasm of the urethral meatus 3 months previously. Physical examination showed a sessile tumor with a pebbled surface originating from the 6-o’clock position of the urethral meatus, involving the glans and the prepuce frenulum (Figure 1a–1c). Surgical excision and urethral meatoplasty were performed. The pathological diagnosis of squamous cell papilloma was made by hematoxylin and eosin staining (Figure 1d). Immunohistochemical examination revealed that the human papillomavirus (HPV) pan (Figure 1e) and HPV-16 (Figure 1f) markers were positive. The boy recovered uneventfully, and there was no evidence of recurrence during 6 months of follow-up.

Figure 1.

Squamous cell papilloma. (a) The top view, (b) the lateral view, and (c) the lateral view of the tumor at the urethral meatus. (d) Histological image of hematoxylin and eosin staining. (e) Human papillomavirus (HPV) pan marker was positive. (f) HPV-16 marker was positive.

Squamous papilloma is a common intraoral lesion, but it is rare in the urethra, especially at the urethral meatus. To date, the study of a relatively large number of urethral squamous papilloma patients included five patients.3 That study and another of three patients with urethral squamous papilloma both found that all patients were negative for HPV DNA, which suggested that squamous papilloma is a distinct entity not associated with condyloma acuminatum.2 Additionally, the authors believed that risk factors included smoking and exposure to aromatic amines, which is similar to the findings for urothelial carcinoma. We found that HPV infection was related to squamous papilloma in our patient, which is consistent with esophageal and oral lesions.4,5 The young age of our patient means that smoking and exposure to aromatic amines were unlikely to have been pathogenic factors. Some investigators are concerned that squamous papilloma can progress to low-grade papillary urothelial carcinoma.1 Guo et al.3 followed up four patients and 3 of them had no evidence of cancer. One of them developed urothelial carcinoma and had a history of low-grade urothelial carcinoma. Therefore, Guo et al.3 and Cheng et al.,2 who followed up four patients with squamous papilloma of the urinary tract, considered that squamous papilloma was a benign proliferative squamous lesion and was accompanied by no appreciable risk for developing cancer. Surgical removal is a routine treatment, and recurrence is rare.

AUTHOR CONTRIBUTIONS

CW collected the data, reviewed the literature, and drafted the manuscript. XM contributed to the follow-up and revision of the manuscript. Both authors read and approved the final manuscript.

COMPETING INTERESTS

Both authors declare no competing interests.