The correct answer is lichen planus (choice “c”).
Condyloma accuminata can demonstrate amazing lability, sometimes appearing decades after exposure. And spouses may not always be truthful when questioned about such exposure. To further confuse the issue, it's entirely possible that a patient may be unaware he or she has condyloma. So, this might well have been condyloma. But the differential for penile lesions would include this condition—and more.
Psoriasis (choice “a”) commonly affects the penis, manifesting as pinkish plaques and papules. But there is a good chance that examination would have revealed corroborative signs of this disease. Furthermore, the histologic results would have been entirely different.
While syphilis (choice “b”), especially in its primary stage, can present with nonhealing sores, in no way do they resemble the patient’s lesions. There is also no source for such an infection. And biopsy would have shown a predominately plasma cell infiltrate in an entirely different pattern.
Lichen sclerosus et atrophicus (choice “d”) is quite uncommon, especially on the penis, where it is usually known as balanitis xerotica obliterans (BXO). As its name suggests, BXO is usually atrophic—therefore macular—and whitish. Exclusive to uncircumcised men, it bears no resemblance to condyloma.
Though idiopathic, lichen planus is not contagious. Unless neglected, this condition seldom causes any suffering aside from mental anguish over its appearance. To make a more accurate diagnosis, it is always helpful for providers to consider a mnemonic device for “7 Ps” associated with lichen planus:
Fortunately, lichen planus affecting the penis responds readily to treatment with mid-strength topical steroid cream and the "tincture of time," which improves its appearance until it eventually disappears. For this patient, the PCP treated the affected area with triamcinolone 0.1% cream bid for 2 weeks. This was then applied once a day every other day for a month, which cleared the patient’s lesions.