Diagnosis: Vegetative Pyoderma gangrenosum
Histology: florid pseudoepitheliomatous hyperplasia, lymphocytic vasculitis and dense dermal acute and granulomatous inflammation (Fig. 2); GMS, AFB and gram stain for fungal, mycobacterial and bacterial organisms was negative
Clinical Course: She was placed on oral prednisone, with plans to continue high dose steroids until the disease resolves. Once improvement is seen in the skin disease, the prednisone will be slowly tapered. It will be imperative that her diabetes mellitus is carefully monitored while she is on oral steroids.
Discussion: Pyoderma gangrenosum (PG) presents itself classically as an ulcer with a necrotic undermined border whose base can be prulent or vegetative. There are currently five types of PG: classic, bullous, vegetative, pustular and peristomal, and it often occurs de novo (70%) or due to pathergy (30%) (trauma leading to initial ulceration). PG most often occurs on the lower extremities, but less frequently occurs on the upper extremities, and has been reported to occur on the breasts. Over 80% of PG affecting the breast occurs 4 days to 6 weeks following breast surgery, and it characteristically spares the nipple/areola as was seen in this case.
Histopathology of PG is nonspecific, but early lesions have a neutrophilic vascular reaction, often around hair follicles. This makes the diagnosis of PG one of exclusion. The lesions are never infectious or gangrenous as the name leads one to believe.
Fifty percent of patients also have an underlying systemic disease, most commonly inflammatory bowel disease, rheumatoid arthritis or a myeloproliferative disorder. Those patients without evident systemic disease are still believed to have an underlying immunologic abnormality, though specific details are not yet understood.
Standard treatment most commonly includes local intralesional steroids and/or systemic steroids. Second line agents include immune modulators like cyclosporine, methotrexate, azathioprine and most recently infliximab.
Patients should also undergo workup for systemic diseases that can be associated, including a colonoscopy for possible inflammatory bowel disease or a bone marrow biopsy if an immunocompromised state is suggested. Surgery and debridement should be avoided because of the risk of further pathergy.
This case is presented by Lindsey Brodell, MD, Donna Hepper, MD, Milan Anadkat, MD