Penile pyoderma gangrenosum.

A 70-year-old man presented with indurated penile ulcers of 1-month duration. Initial biopsy was reported as chronic ulcer. A repeat biopsy done due to inadequate response to doxycycline showed features of pyoderma gangrenosum. The ulcer healed with a course of steroids and has not recurred till date.

INTRODUCTION

Pyoderma gangrenosum (PG) is a rare, chronic, often destructive, inflammatory skin disease. It is characterized by a painful nodule or pustule which breaks down to form a progressively enlarging ulcer with a raised, tender, undermined border. It can occur by itself or with an underlying systemic disorder.[1] PG most commonly occurs on the lower extremities and trunk of adults aged 40-60 years.[2]

CASE REPORT

A 70-year old male, living with spouse presented with relatively asymptomatic ulcers over the penis of 1 month duration. He denied any extramarital contact. He was not a known diabetic or hypertensive.

General examination was within normal limits. Local examination showed two indurated ulcers 1.5 × 1 cm and 0.5 × 0.4 cm over the penis at the junction of foreskin and coronal sulcus. The ulcers bled on touch. There was no inguinal or femoral lymphadenopathy [Figure 1].

Figure 1

Shallow ulcers with irregular margins and indurated base over the penis at the junction of foreskin and coronal sulcus

Squamous cell carcinoma penis, tuberculous ulcer, donovanosis, and Herpes genitalis (either because of immunocompromise or development of resistant mutation) were considered as the differential diagnosis. The following investigations: Routine blood and urine examinations, peripheral smear, ANA, rheumatoid factor, VDRL, ELISA-HIV, HBsAg, anti-HCV, Mantoux test, Chest X-ray PA view, Ultrasound abdomen, gram stain from the ulcer, and tissue smear for Donovan bodies were negative or within normal limits.

A biopsy was done, and the patient was started on doxycycline 100 mg twice daily. Biopsy revealed a chronic ulcer with no evidence of malignancy. Tissue culture for mycobacteria and fungi were negative. Despite 3 weeks of doxycycline, the ulcers were found to be increasing in size and extent. A repeat biopsy was done, and the patient was circumcised to accelerate the healing process.

The second biopsy showed an ulcer with hyperplasia of the adjacent epidermis and a dense inflammatory cell infiltrate in the dermis composed of lymphocytes, neutrophils, Langhans, and foreign body type of multinucleate giant cells. Proliferation of capillary-sized blood vessels with perivascular accumulation of inflammatory cells was noted [Figure 2].

Figure 2

(a, b): A dense inflammatory cell infiltrate in the dermis composed of lymphocytes, neutrophils, Langhans, and foreign body type of multinucleate giant cells

With these histopathological findings and clinical correlation, an alternative diagnosis of PG was considered. He was started on 40 mg of prednisolone per day. The ulcer started healing on the third day. Prednisolone was tapered and stopped by 4 weeks. There has been no recurrence even 12 months after stopping treatment [Figure 3].

Figure 3

4 weeks after treatment

This case is reported for its extreme rarity. PG is rare, and there are only very few reports of penile PG.

DISCUSSION

The initial description of PG was done by Brunsting in the year 1930.[2] PG is a rare noninfectious neutrophilic dermatosis commonly associated with underlying systemic disease. The diagnosis is based on typical clinical features and exclusion of other cutaneous ulcerating diseases.[3] PG can have a variety of clinical presentations such as ulcerative, pustular, bullous, and vegetative forms.[4] The disease begins with small tender papules or pustules that evolve into painful ulcers with characteristic violaceous undermined edges. Lesions may be solitary or multiple and heal with atrophic cribriform scar. PG may be associated with constitutional symptoms.[5]

Although the disease is idiopathic, in 25-50% of patients, an underlying immunologic abnormality may exist.[6] The most common associations are inflammatory bowel disease (ulcerative colitis and Crohn's disease), arthritis (seronegative arthritis and rheumatoid arthritis), and hematologic diseases (myelogenous leukemia, hairy cell leukemia, myelofibrosis, and monoclonal gammopathy). Other neutrophilic dermatoses associated with PG are Behçet's disease, subcorneal pustular dermatosis, and Sweet's syndrome.[1]

Systemic corticosteroids or cyclosporine are the first line of therapy for disseminated and localized disease. Alternatives such as mycophenolate mofetil, tacrolimus, infliximab, or plasmapheresis may also be used.[7]

The diagnosis of PG of the genitalia is made on the exclusion of other causes of genital ulcers-infectious diseases (syphilis, chancroid, genital herpes, cutaneous tuberculosis, donovanosis, amoebiasis, and deep fungal infections), drug eruptions, traumatic ulcerations, Behcet's disease, and neoplasms. A biopsy is helpful to exclude most of these conditions, and this would make diagnosis of PG more obvious.

PG localized to the penis is rare.[8] This case is reported to highlight the fact that rare conditions like PG should be a differential diagnosis of genital ulcers, which do not respond to usual modes of treatment. Penile PG in the elderly may masquerade as squamous cell carcinoma penis and if correctly diagnosed could avert mutilating surgery.