Crateriform Papules on Penis

Dear Editor,

A 28-year-old married male presented to our outpatient department with complaints of raised skin lesions over the genital region for the past 2 months. It was associated with occasional itching. There was no history of promiscuity. On examination, there were three pigmented crateriform papules of varying sizes over the inner aspect of the prepuce [Figure 1]. The papules were smooth and soft on palpation. Serology for syphilis and the human immunodeficiency virus types 1 and 2 were both nonreactive. The clinical differential diagnosis includes molluscum contagiosum, human papillomavirus (HPV) warts, bowenoid papulosis, ectopic sebaceous glands, and genital porokeratosis.

Figure 1.

Multiple pigmented crateriform papules over inner aspect of prepuce

Dermoscopy showed some aggregated white or yellow nodules within the crater and a linear vessel in the periphery [Figure 2]. On histopathological examination, the epidermis showed surface indentation which corresponds clinically with the central crater. There was an expansion of the normal lobular sebaceous gland with mature sebocytes and a peripheral germinative layer in the superficial dermis. Few lobules communicate with surface epithelium through the common duct with mild interstitial mixed inflammatory infiltration. Cellular atypia was not seen [Figure 3]. The histopathological differential diagnosis considered were sebaceous hyperplasia, sebaceous adenoma, and Fordyce spots. The differences among these were shown in Table 1.

Figure 2.

Dermoscopy shows yellow and white nodules (black arrow) and non branching linear vessel (yellow arrow) (Dermlite 4, polarising mode, 10x)

Figure 3.

Surface indentation with expansion of normal lobular sebaceous gland with mature sebocytes and a peripheral germinative layer in superficial dermis and few lobules communicate with surface epithelium through common duct (H&E stain, 10x)

Table 1.

The difference between sebaceous hyperplasia, Fordyce spots, and sebaceous adenoma

Sebaceous hyperplasia	Fordyce spots	Sebaceous adenoma
Sebaceous glands are composed of numerous lobules grouped around a centrally located sebaceous duct	Mature sebaceous lobules are situated around a small sebaceous duct leading to the surface epithelium	Incompletely differentiated sebaceous lobules that are irregular in size and shape. Both basaloid and sebaceous cells were seen. Cytological atypia absent

As our case had numerous lobules opening through a common duct, a diagnosis of sebaceous hyperplasia (SH) was made. As the patient was cosmetically concerned, cryotherapy was done.

Sebaceous glands form part of the skin appendages and are present in large numbers on the face, scalp, and ears in association with hair structures. Free sebaceous glands (those not associated with the hair follicle) are occasionally found in some areas of modified skin, such as the nipple (Montgomery tubercles), lips (Fordyce’s spots), and the inner surface of the prepuce (Tyson’s glands).[1]

Sebaceous glands can be seen in the oral mucosa or genitalia in adults as ectopic glands or “Fordyce spots,” though it is not a common area to be found. SH is a benign increase in the size of the sebaceous lobule surrounding the follicular infundibulum; so, it usually appears in hairy areas. It affects adults of middle age or older, mainly in the face and other actinic damaged areas.

Facial SH in the elderly is due to decreased cellular turnover secondary to decreased androgen levels, with a resulting increase in the size of the gland.[2] However, it does not explain the hyperplasia which occurs in the glands of the penile shaft. In contrast, the majority of penile SH cases seem to appear at an earlier age. The higher sensitivity of the sebaceous cells to androgens, leading to an increase in cellular proliferation may be a possible cause of penile SH.[3]

There are several cases of SH of genital location in adults,[4] not only in the penis but also in the vulva.[5] Some of them show a typical linear pattern of distribution,[4] which has been interpreted as a Koebner phenomenon or induced by cosmetics.[4,6]

Dermoscopy shows yellow and white aggregates at the center of the lesion. They correspond to hyperplastic sebaceous glands histopathologically. These are surrounded by non-branching vessels which do not cross the center of the lesion. This pattern of non-arborizing vessels is called “crown vessels” and this vascularity is specific for hyperplastic sebaceous glands. Sometimes, the ostium of the gland is seen as a small crater.[7]

They mimic sexually transmitted diseases (STDs) like molluscum contagiosum (MC) and genital warts. Clinically, MC appears as discrete pearly-white umbilicated papules and genital warts have a highly variable appearance and may be flat, dome-shaped, cauliflower-shaped, or pedunculated.

In conclusion, in adults, we must keep that non-infectious causes may mimic STDs and a high index of suspicion for alternative diagnoses should be thought. Apart from the classical presentation of umbilicated papules, SH can also present like crateriform papules as in our case.

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