Summary

A 75 years old man presented to the Social Hygiene Clinic (SHC) with an asymptomatic warty growth on his penis for 2 months. The lesion increased in size gradually. He had a history of unprotected sex with a commercial sex worker in China 10 months ago. Although his clinical history was highly suggestive of genital warts, physical examination revealed a warty lesion which was not fully compatible with the clinical features of a genital wart. Skin biopsy was then performed which showed squamous cell carcinoma in situ (SCC in situ). In view of possibility of sampling error, he was subsequently referred to the surgical department for treatment.

摘要

一名75歲男子，因過去兩個月在陰莖上呈疣狀腫瘤而到社會衛生科門診求醫。患處逐漸增大。他在十個月前曾有召妓紀錄。雖然病歷與性病疣相當吻合，但臨床徵狀卻不符合，在進行皮膚組織切片檢查時，病理學診斷結果顯示原位鱗狀細胞癌，因皮膚組織檢查可能有抽取的誤差，病人其後被轉介到外科部門進行治療。

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Introduction

Squamous cell carcinoma (SCC) of the penis is a rare malignancy. In the United States, it accounts for only 0.4% of all cancers in men.¹ It can present as plaque, nodule, ulcer or warty lesion. We report below a man suffering from squamous cell carcinoma in situ of the penis presented as a warty lesion.

Case report

A 75 years old man presented to our sexually transmitted disease (STD) clinic with a asymptomatic warty growth over the penis for 2 months. The lesion increased in size gradually. The patient was an ex-smoker and ex-drinker. He had history of gallstones and pancreatitis. He had circumcision after puberty. He denied any past history of STD. For his sexual history, he had vaginal sex without condom with his wife in China 2 months before the consultation. He had vaginal sex without condom with a commercial sex worker (CSW) in China 10 months before the consultation. He was now retired and he previously worked as a gardener.

Physical examination showed a warty crateriform lesion over his glans penis. (Figure 1) It was 2 cm x 1.8 cm in size. There was no palpable lymph node and abdominal examination was unremarkable. The clinical differential diagnoses included genital wart, squamous cell carcinoma in situ, squamous cell carcinoma, Buschke-Lowenstein tumour and keratoacanthoma.

An incisional skin biopsy was performed which showed the lower portion of the epidermis was involved by moderate dysplasia - cellular disorientation, cytological and nuclear pleomorphism with increased mitosis and apoptosis. (Figure 2) There was no definite dermal invasion. The histopathologic features were compatible with squamous cell carcinoma in situ of the penis. In view of clinical morphology of the lesion, and the likelihood of invasive SCC which may be missed due to sampling error, the patient was referred to the surgical team for complete excision and hence thorough pathological assessment.

The dysplastic cells occupy the middle to lower epidermis. The undersurface of the epidermis is irregular but there is no definite dermal invasion.

Complete excision and reconstruction of the penis was performed by the surgical team. Histopathology revealed moderate differentiated squamous cell carcinoma with focal invasion into the stroma. New tumour growth was subsequently found at the initial excision site. Since the patient strongly refused amputation of the penis, he was referred to the clinical oncology team for radiotherapy.

Discussion

Squamous cell carcinoma of the penis is a rare malignancy that may mimic genital wart. The predicted lifetime risk in the United States and Denmark was 1 in 1437 men² and 1 in 1694 men³ respectively. The risk factors for SCC of the penis include genital warts,⁴ multiple sexual partners,⁵ past history of sexually transmitted diseases,⁴ smoking,⁶ previous genital infections,⁴ etc. Of all these risk factors, genital wart is the most significant risk factor. Our case had some risk factors for penile cancer which included smoking and multiple sexual partners. SCC of the penis is most commonly diagnosed in the 60-70 years of age. It may occur at any site on the penis, but most often on the glans (48%)⁷ like this gentleman. Its clinical presentation varies from slightly elevated areas of induration, ulcers, nodules to warty growth. It metastasizes via the lymphatics - firstly, to the inguinal lymph nodes, followed by pelvic and lastly distant metastasis. Squamous cell carcinoma in situ of penis may progress to SCC if left untreated.

Histopathologic examination is essential to establish the diagnosis and to provide exact information about the extension of the tumour in deeper tissues. They are pathologically staged and are graded using the American Joint Committee on Cancer (AJCC) tumour, node, and metastasis (TNM) staging and modified Broders systems, respectively. The TNM system classifies cases into stages I-IV based on the extension of the tumour. The modified Broders classification divides tumours into 4 histologic grades ranging from well differentiated to poorly differentiated.⁸

Management of the penile SCC varies according to the staging. For treatment of squamous cell carcinoma in situ, first line therapy is wide local excision.⁹ Other modalities that have been employed include local applications of fluorouracil cream and CO2 laser.¹⁰ The treatments of other stages of SCC include penile amputation, bilateral ilioinguinal LN dissection, radiotherapy, chemotherapy, or combination therapy. An overall 5 year survival rate of 52% has been reported: 66% in patients with negative lymph nodes and 27% in patients with lymph nodes.¹¹ Death from cancer is usually a consequence of local complications: infection, haemorrhage of the ulcerated tumour or ulcerated inguinal metastasis. In our case, the initial skin biopsy revealed squamous cell carcinoma in situ of the penis. However, one must be cautious about the possibility of sampling error. It will greatly affect the treatment issues and hence the prognosis. Our patient was therefore referred to the surgical team for complete excision. Excisional biopsy showed moderate differentiated squamous cell carcinoma with focal invasion into the stroma. Since our patient refused amputation of the penis, he was referred to clinical oncology team for radiotherapy.

Key messages

1. Not all warty growths in the genital region are genital warts.
2. One must be aware of the possibility of sampling error as a pitfall in taking a biopsy and clinicopathological correlation is the key to correctly interpreting the pathology report.

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References