Penile Syringoma

Abstract

Background: Syringoma of the penis is rare. Purpose: This paper describes two men with syringoma of the penis and summarizes the clinical features of previously reported men with this condition. Methods: A 25-year-old African man presented with a nonpruritic flesh-colored papule on the right side of his proximal dorsal penile shaft and a 22-year-old Caucasian man presented with multiple asymptomatic flesh-colored papules on his ventral and lateral penis. Neither man had similar lesions elsewhere or a family member with this condition. Reports of patients with penile syringoma were identified using a medical search engine (PubMed Central) and references included in the published papers on this subject. Results: Microscopic examination of both men’s papules showed syringoma. Including these individuals, syringoma exclusively localized to the penis has only been reported in 11 men. It usually presents as multiple asymptomatic flesh-colored papules on the dorsal penile shaft of men less than 30 years of age. Epithelial-lined cystic spaces containing homogenous eosinophilic material are noted in the fibrotic upper dermis. The papules do not recur following excisional biopsy. Conclusion: Syringoma exclusively located on the penis is extraordinary and has only been reported in 11 men. It presents as a solitary papule or multiple asymptomatic papules on the penile shaft. Microscopic examination shows epithelial structures and eccrine ducts with comma-like tails resembling tadpoles in the fibrotic upper dermis; amorphous pink secretion is often present in the epithelial-lined spaces. Excision of the penile papules not only provides the diagnosis, but also successfully removes the individual lesion without recurrence.

Syringomas are benign eccrine tumors that typically present as symmetrically distributed dermal papules on the lower eyelids; however, they may appear on other areas of the body—particularly in individuals who experience an eruptive onset of the lesions. Penile syringoma are rare. The authors present the cases of two men with penile syringomas and review the characteristics of previously reported individuals with syringomas exclusively located on their penis.1-8

CASE REPORTS

Case 1. A 25-year-old healthy heterosexual African man presented with a two-year history of an asymptomatic papular lesion on the penis that was slowly increasing in size. He was beginning a new relationship and wanted to be certain that he did not have a contagious disease. No similar lesions were present elsewhere. No other family member had a similar problem.

Clinical examination showed a firm, smooth, 2x2mm, flesh-colored papule on the right proximal dorsal penile shaft (Figure 1). The remaining physical examination revealed no other physical abnormalities.

Figures 1A and 1B.

Distant (A) and closer (B) views of syringoma of the penis presenting as a solitary asymptomatic smooth, firm, flesh-colored nodule on the right side of the proximal dorsal penile shaft of a 27-year-old African man.

An excisional biopsy of the lesion was performed under local anesthesia. Microscopic examination of the penile papule showed a normal epidermis with a proliferation of ductal spaces and aggregates of epithelial cells in the upper dermis, which had a fibrous stroma (Figure 2). Many of the spaces were predominantly lined by two layers of epithelial cells and some were filled with amorphous pink secretion (Figure 3).

Figure 2.

Microscopic examination—low magnification—of the penile papule from the 27-year-old African man shows epitheliallined ductal spaces embedded in a fibrous stroma (hematoxylin and eosin, ×4).

Figures 3A and 3B.

Microscopic examination—intermediate (A) and higher (B) magnifications—of the penile syringoma from the 27- year-old African man described in Case 1 shows ducts, aggregates, and strands of epithelial cells in the fibrous dermis; some of the ducts are lined by two rows of epithelial cells and contain homogenous eosinophilic material (hematoxylin and eosin: A, ×10; B, ×20).

Correlation of the clinical presentation and the pathologic findings established a diagnosis of a solitary syringoma of the penis. Complete healing of the biopsy site occurred. There was neither recurrence nor additional new lesions.

Case 2. A 22-year-old healthy heterosexual Caucasian man presented with a less than one-year history of multiple asymptomatic papular lesions on the penis. He was concerned regarding the possibility of venereal warts. He had no similar lesions elsewhere. No other family member had a similar problem.

Clinical examination showed numerous, firm, smooth, 1 to 4mm, flesh-colored papules on the ventral and lateral penile shaft (Figure 4). The remaining physical examination revealed no other physical abnormalities.

Figure 4.

Penile syringomas presenting as multiple asymptomatic flesh-colored papules on the ventral and lateral shaft of the penis of a 22-year-old Caucasian man

A biopsy of one of the lesions was performed under local anesthesia. Microscopic examination of the penile papule showed a proliferation of ducts predominantly lined by two rows of epithelial cells in the upper dermis; some of the ducts had comma-like tails giving them the appearance of tadpoles. The surrounding stroma was fibrous and some of the ductal spaces were filled with homogenous eosinophilic material.

Correlation of the clinical presentation and the pathologic findings established a diagnosis of multiple syringomas of the penis. Complete healing of the biopsy site occurred. The patient was reassured that the lesions were neither condyloma nor a sexually transmitted disease; he decided to observe the remaining lesions without any additional therapeutic intervention.

DISCUSSION

Syringomas are benign, small, soft, usually asymptomatic, flesh-to-yellow-colored, dermal papules that are derived from the intraepidermal portion of eccrine sweat ducts. Penile syringomas are an uncommon phenomenon. To the best of the authors’ knowledge, there are only 11 men (including the patients described herein) with syringomas exclusively located on the penile shaft (Table 1).1-8

TABLE 1.

Characteristics of patients with syringoma exclusively located on the penis^a

CASE	PA	DUR	OA	SIZEb	SITEc	MORPHOLOGY	TX	REF
1	18	1	17	2–3	D	Pink to flesh-colored clustered papules	NS	1, Case 2
2	19	<1	19	4–7	D and L	Slightly yellow to flesh-colored, round to oval, soft papules	NS	2
3	20	5	15	A few	D	Skin-colored, smooth, rounded, slightly elevated papules	Mcd	3
4	22	<1	22	1–4	V and L	Flesh-colored, smooth papules	Ob	CR, Case 2
5	25	2	23	2x2e	D: prox	Flesh-colored, firm papule	Exf	CR, Case 1
6	27	<1	27	2–3	D and L	White-yellow papulesg	NS	1, Case 1
7	30	17	13	2–4	D and L: mid	Reddish brown, round and irregular, dome- shaped, soft papulesh	Exi	4
8	31	15	16	2–5	D and L	Yellowish to flesh-colored, firm papules	Nk	5
9	32	20	12	1–3	D and L	Skin-colored, dome-shaped, soft papules	NS	6
10	35	NS	NS	NS	NS	Flesh-colored, smooth papules	Nl	7
11	41	1	40	Sm	D and V	Light brown, somewhat dark, dome-shaped papules	N	8

^aAbbreviations: CR=current report; D=dorsal; Dur=duration (years); Ex=excision; L=lateral; Mc=microelectro-coagulation; N=none; NS=not stated; OA=onset age (years); Ob=observe; PA=presentation age (years); prox=proximal; Ref=reference; Sm=small; Tx=treatment; V=ventral

^bThe size of the multiple lesions is measured in millimeters.

^cSite refers to the location of the syringoma on the penile shaft.

^d”The patient was treated with various sessions of microelectro-coagulation.”

^eThe patient only had a single lesion.

^fThe excisional biopsy not only provided the diagnosis, but also successfully treated the lesion without subsequent recurrence.

^gThe individual lesions coalesced into four slightly elevated, light brownish-red plaques that measured up to 10mm.

^h”A few larger lesions formed by coalescence of the smaller papules; the papules were discrete, with some tendency to grouping and linear arrangement.”

ⁱ”The patient considered his lesions unsightly, primarily because of their bright red color change associated with penile erection. He requested that the lesions be removed; 25 [of nearly 40] papules were excised…and these areas healed normally.”

^j”The lesions gradually spread over the shaft of his penis, increasing in number and size.”

^k”After patient reassurance and discussion of treatment options, the patient declined further treatment.”

^lHis wife had cervical dysplasia and he had biopsy-confirmed condyloma acuminatum; however, the syringoma lesions did not respond to topical application of 25% podophyllum in tincture of benzoin. Since the biopsy-confirmed syringoma “…were asymptomatic and benign, no further treatment was instituted.”

Syringomas, particularly in some of the individuals with eruptive onset of their lesions, may be present in more than one family member.9-11 However, there was no family history of similar lesions in the men with penile syringomas. Also, none of these individuals had any of the conditions that have been associated with development of syringomas, such as Costello syndrome, Down (trisomy 21) syndrome, Ehlers-Danlos syndrome, Nicolas-Balus syndrome, and Marfan syndrome.11-15

The penile syringoma initially appeared when the patients were between the ages of 12 to 40 years (mean=20 years; median=18 years); indeed, the onset age of the syringomas on the penis was less than 20 years old for 60 percent of the men and less than 30 years old for 80 percent of the patients. The new lesions were present from four weeks2 to 20 years6 (median=1.5 years) before the individuals sought medical attention.

The most common reason that the men with syringomas on the penis went to see a physician—including both of the patients described herein—was concern that the penile lesions were a manifestation of a sexually transmitted disease.5-8 Some of the men were distressed by the cosmetic appearance of the papules4-6; for example, one of the individuals, a 30-year-old man, noticed that his erection was associated with a bright red color change of the lesions.4 Another patient, a 35-year-old man who had a history of biopsy-confirmed condyloma acuminata and whose wife had cervical dysplasia, presented for a second opinion when his residual lesions did not improve following topical application of 25% podophyllum in tincture of benzoin.7

Syringomas of the penis usually present as multiple lesions (91% of patients) on the dorsal and lateral penile shaft (5 patients); only one patient, the 25-year-old African man described in this report, presented with a solitary lesion on the dorsal shaft of his penis. Less commonly, syringomas appeared on either the dorsal (2 patients), dorsal and ventral (1 patient), or the ventral and lateral (1 patient) penile shaft. None of the men with penile syringomas had lesions on their scrotum; this is in contrast to women who develop genital syringomas, which typically occur on their vulva either as the only location or as part of a widespread eruption of similar lesions.16

The dermal papules of penile syringomas were asymptomatic. They ranged in size from 1 to 7mm and were described as smooth, rounded, or dome-shaped. The individual lesions were either flesh (or skin) colored, brown, reddish-brown, white-yellow, or pink.

The clinical differential for penile syringomas is listed in Table 2.1-8 An excisional biopsy can readily be performed to not only remove one or more of the lesions, but also for pathology evaluation. The changes noted on the microscopic examination of a penile syringoma are similar to those observed in a syringoma that is not located on the shaft of the penis. There are epithelial-lined ductal spaces and cysts in the upper dermis. Some of the spaces contain homogenous eosinophilic material. Some of the epithelial structures and cystic spaces have comma-like tails resembling tadpoles.

TABLE 2.

Clinical differential diagnosis of papular lesion of the penis

BENIGN TUMOR

Angiofibroma

Epidermal inclusion cyst

Sebaceous hyperplasia

Syringoma

DERMAL DEPOSITION

Calcinosis cutis

GRANULOMATOUS DISORDER

Granuloma annulare

Sarcoidosis

PAPULOSQUAMOUS DERMATOSES

Lichen nitidus

Lichen planus

Psoriasis vulgaris

VIRAL-ASSOCIATED CONDITIONS

Bowenoid papulosis

Condyloma acuminatum

Molluscum contagiosum

Treatment of syringomas on the penis is elective; indeed, treatment was only commented on for seven of the patients. Surgical removal of multiple lesions was performed in a 30-year-old man4 and microelectro-coagulation of many lesions over several sessions was done in a 20-year-old man.3 The biopsy removed the entire syringoma in one of the patients described in this article and no further therapeutic intervention was necessary. The other four individuals (including the other patient described in this article), after being reassured of the benign biological behavior of the lesions, decided to observe their remaining syringomas without any additional treatment.5,7,8

CONCLUSION

Syringoma of the penis is a benign, albeit rare, condition usually appearing as multiple asymptomatic papules on the penile shaft of young men less than 30 years of age. They are often small, 1 to 4mm, flesh-colored, smooth lesions. The patients frequently seek medical attention because they are worried about the possibility of a sexually transmitted disease, such as condyloma accuminata, or are concerned regarding the cosmetic appearance of the lesions. The clinical differential diagnosis of penile syringoma includes other benign adnexal tumors, cutaneous lesions associated with sexually transmitted diseases, and even inflammatory or neoplastic skin conditions. A lesional biopsy readily establishes the diagnosis. Characteristic pathological changes associated with syringoma are observed: epithelial structures and epithelial-lined (predominantly by 2 cell layers) ductal spaces containing eosinophilic homogenous material in a fibrous dermal stroma. Some of the patients elected to have either surgical removal or destruction of some of their additional syringoma. However, most patients, after being reassured of the benign biological behavior of the lesions, decided to observe the remaining syringomas without any subsequent intervention.