Isolated penile Kaposi’s sarcoma in a HIV-positive patient stable on treatment for three years

Introduction

Kaposi’s sarcoma (KS) is an AIDS-defining illness and the commonest tumour found in HIV patients. KS is caused by the human herpesvirus-8 (HHV-8).¹ Penile KS is a rare presentation, and the majority of reported cases were published before the introduction of antiretroviral therapy (ART).^2,3,4,5 To our knowledge, this is the first case report to describe two KS lesions on the penis of a HIV-positive patient with a CD4 count above 200 cells/mm³ and suppressed viral load whilst being managed with ART.

Case report

A 40-year-old British Caucasian man was diagnosed with HIV in October 2006. He has been treated with a fixed dose combination of tenofovir, emricitabine and efavirenz (as Atripla) since February 2007. He had a CD4 count of 551 cells/mm³ and an undetectable viral load in March 2012. He presented with a one-week history of a pedunculated lesion on his penis. A genital examination revealed a solitary lesion measuring 5 mm in diameter on the inner layer of the prepuce. The lesion was violaceous and non-tender. Extragenital examination was normal. Under local anaesthesia, an excision of the lesion was performed. Histological examination confirmed a diagnosis of penile prepuce KS.

Two months later, he presented to the genito-urinary medicine (GUM) clinic with a new skin-coloured lesion at the frenulum of the glans penis. The lesion measured 6 mm × 6 mm × 3 mm and had a broad base. The surface was smooth (Figure 1). Extragenital examination was normal. He was initially treated with cryotherapy and 5% imiquimod as the lesion was presumed to be a genital wart. This was unsuccessful, and a surgical excision biopsy was conducted under local anaesthesia. At this time, his CD4 count was 437 cells/mm³ (23%). He had an undetectable viral load and undetectable serum HHV-8 DNA. OPEN IN VIEWER

The biopsy result showed irregularly arranged interlacing fascicles of spindle-shaped cells containing oval to elongated nuclei of clumped chromatin and occasional prominent nucleoli. Mitotic figures were identified. The intervening scanty stroma showed extravasation of red blood cells, associated with acute and chronic inflammatory cells (Figure 2). OPEN IN VIEWER

A CT scan of his chest, abdomen and pelvis was normal with no evidence of visceral KS or lymphadenopathy. He remains disease-free one year later.

Discussion

The first case of penile KS was described in 1902. ² It is estimated that 20% of patients with systemic KS will develop lesions at the genitalia and 3% of patients will develop the lesion initially at the genitalia. ³ We conducted a literature search using MEDLINE and CINAHL using search terms ‘penile’, ‘genital’ and ‘Kaposi sarcoma’ for published cases between 2002 and 2012. This found a limited number of reports involving penile KS in HIV-positive patients.

A major risk factor for the development of KS is a low CD4 count. ⁶ The ability of ART to suppress HIV and allow immune reconstitution has led to a decrease in the incidence of KS.^6,7 HIV patients with normal CD4 counts can still develop rare presentations of KS. ⁶

The typical clinical feature of primary penile KS is a purple papule or macule located on the glans.^2,8 Nodules, plaques, multiple papules, wart-like or pedunculated lesions are less common. ⁹ The patient’s second KS lesion was pale (Figure 1). An explanation for this could be as a result of cryotherapy given weeks before biopsy. Our experience confirmed that some KS lesions could be misdiagnosed as genital warts, which are not uncommon presentations in GUM clinics. Physicians should remain suspicious of any atypical lesions presenting at the penis and not responding to effective therapy. One should consider undertaking a biopsy in this setting, especially as there is growing evidence of penile KS occurring in HIV-negative individuals. ⁸

Review of the literature over the past 10 years has shown lack of reported primary penile KS in HIV-positive individuals (Appendix). Only one other case report of primary penile KS in an individual with HIV infection was found. This case differs from our case in that the gentleman had severe immune suppression and the lesions were treated with and responded appropriately to ART. ⁹ Another case series describes nine patients who had persistent extragenital KS despite immune recovery with CD4 counts above 300 cells/mm³ and HIV-1 viral load below 300 copies/ml. ⁶ Our case is therefore unique in that this gentleman presented with primary penile KS lesions whilst already immune-reconstituted and adherent to ART.

A range of methods have been used in treating penile KS. We conducted a surgical excision, which agrees with the general consensus of other published studies. Other case reports have achieved remission with ART, radiotherapy, systemic or local chemotherapy.^8,10–18

Penile KS can occur in immune-reconstituted HIV patients and should be included in the differential diagnoses of any suspicious penile lesions.