Introduction
Squamous cell papilloma is a benign epithelial tumor rarely observed in the distal urethra in both sexes (1). The majority of lesions are seen in women in the external meatus. Urethral caruncle, urethral prolapse, urethral diverticulum and periurethral gland abscess are included in the differential diagnosis (2). Generally, these lesions are observed in hypoestrogenic state in post-menopausal women and are reported to develop from urethral caruncle background (3). Careful histological investigation is important for diagnosis (2). The clinical importance of these non-invasive lesions is unknown, though some case reports are available in the literature.
In this paper, we aimed to present an 18-year-old male patient with the diagnosis of squamous cell papilloma in the distal urethra and a literature review.
Case Presentation
An 18-year-old male patient admitted to our clinic with the complaints of intermittent dysuria and occasional reduction in urine flow rate in recent times. Physical examination revealed a polypoid lesion protruding from the external meatus (Figure 1). There was no other pathology identified in the external genital area. Due to the possibility of multifocality, urethrocystoscopy was planned. Urethrocystoscopy showed a solitary polypoid lesion in the distal fossa navicularis, protruding from the external meatus. Urethroscopy of the anterior and posterior urethra appeared to be normal, and cystoscopy revealed no additional pathology in the bladder. Surgical excision was performed for the polypoid lesion. Histologically, it was composed of papillary cores with overlying benign squamous epithelium (Figure 2). Immunohistochemical staining was negative for human papillomavirus (HPV) and p16, thus, pathological diagnosis of squamous cell papilloma was made.
In the postoperative 12th month after surgical excision, the patient had no complaints and was monitored by our clinic with no recurrence.
This study is retrospective designed study.
Discussion
Squamous cell papilloma is a rarely observed benign lesion presenting with irritative urinary symptoms, generally identified in women over the age of 40 years (4). The patient may have symptoms, such as dysuria, intermittent hematuria, difficulty in voiding, low urinary flow rate and residual urine sensation after voiding (4). In women, lesions are generally observed in the distal urethra protruding from the external meatus (4). Evaluation with cystoscopy is an appropriate approach. Urethral caruncle, condyloma accuminatum, urethral prolapse, urethral diverticulum and periurethral gland abscess are important pathologies in the differential diagnosis (2). There is no information related to male cases in the literature, however, for differential diagnosis, anterior urethral pathologies are important. When anterior urethral pathologies are examined, congenital urethral polyp in the anterior urethra, fossa navicularis pathologies (stenosis, Guerin’s sinus), anterior urethral valve, syringocele (dilatation of Cowper’s gland ducts), congenital bulbous urethral stricture, condyloma accuminatum, and especially botryoid sarcoma polyps should be taken into the consideration in the differential diagnosis (5,6,7,8). Definite diagnosis of squamous cell papilloma is made by careful pathological investigation. In a study investigating the correlation of squamous cell papilloma with HPV evaluated verrucous carcinoma, condyloma acuminata and urethral squamous cell papilloma cases, no correlation was observed (8). As a result, to exclude HPV and p16 immunostaining, clear definition of squamous cell papilloma is important. Microscopic investigation of the lesion demonstrates koilocytotic alterations and wrinkled hyperchromatic nuclei of squamous cells (8,9,10). In our patient with a polypoid lesion in the distal fossa navicularis and protruding from the external meatus, urethrocystoscopy was performed to aid differential diagnosis and to research the presence of additional pathologies. When additional pathologies were not identified, surgical excision was performed. Pathological investigation was negative for HPV and p16 in accordance with the literature and the diagnosis of squamous cell papilloma was made. Recurrence after surgery in urethral squamous cell papilloma is rare, however, as there is a limited number of case reports in the literature, definite information cannot be given (8). The largest series in the literature comprises 5 patients. Two of these 5 cases could not be monitored so they were not assessed. Two patients did not have recurrence during follow-up and one patient was reported to have a lesion accompanied by low-degree urothelial carcinoma (11). However, when squamous cell papilloma cases are examined, the majority of patients appear to have a low risk for both urothelial carcinoma and HPV infection (4). There is no clear follow-up plan after surgical excision in the English literature; as a result, it is recommended that a follow-up plan can be determined based on physical examination and presence of symptoms (4). As recommended, we monitored our patient with physical examination and questioning of symptoms; and no recurrence was detected in the postoperative 12th month. In conclusion, urethral squamous cell papilloma is usually a benign lesion, generally occurring in the urethra in women above the age of 40 years and presenting with irritative urinary symptoms. Diagnosis can be made by urethrocystoscopy which is the accepted treatment with surgical excision. The probability of recurrence is usually low. In some cases, these lesions may be found in the female middle urethra and the male anterior urethra; other important anterior urethral pathologies and botryoid rhabdomyosarcoma polyps must be kept in mind for differential diagnosis.
Ethics
Informed Consent: Retrospective study.
Peer-review: Externally peer-reviewed.
Authorship Contributions
Surgical and Medical Practices: H.H.Ö., K.Y., M.U.M., Concept: S.Ç., Design: S.Ç., Data Collection or Processing: S.Ç., Analysis or Interpretation: S.Ç., H.H.Ö., K.Y., M.U.M., Literature Search: S.Ç., Writing: S.Ç.
Conflict of Interest: No conflict of interest was declared by the authors.
Financial Disclosure: The authors declared that this study received no financial support.
