Abstract Number: 83

An atypical case of pemphigus vegetans presenting as an erosive tumour on the back

J. Chen1,2 , C.-Y. Chu3

Meeting: 2021 Dermcoll

Session Information

Date: -

Session Title: Poster Presentations

Session Time: -

A 60-year-old woman presented to the dermatology clinic with a one-year history of a slowly enlarging brown plaque on her back. This was associated with a two-month history of oral ulcers at the buccal mucosa and a one-month his- tory of pruritic plaques in the perineum. She was other- wise well. A biopsy was taken from the plaque on her back and the left inguinal area. Microscopically, both specimens showed inflammatory vegetative lesions with pseudo-carci- nomatous papillomatosis and hyperkeratosis with multiple intracorneal and intraepithelial abscesses containing eosi- nophils and neutrophils, which were densely infiltrated the dermis. Focal acantholysis was appreciated in the speci- men from the back.

A second biopsy of the plaque on the back showed similar histology of epidermal hyperplasia with hyperkeratosis and multifocal subcorneal and intraepidermal pustules com- posed of neutrophils, eosinophils, and degenerated ker- atinocytes. Suprabasal and intraepidermal acantholysis were also seen.

Lastly, direct immunofluorescence study showed positive intercellular space(ICS) staining of IgG and indirect immunofluorescence study demonstrated positive anti-ICS antibody. PAS stain showed no infectious agents other than skin flora.

These findings were consistent with pemphigus vegetans
(PV) in the patient’s clinical context and demographics.

The patient responded to a tapering dose of oral pred- nisolone, topical clobetasol propionate and topical dexam- ethasone Orabase paste.

While PV commonly presents in intertriginous areas, it is interesting to note the unusual location that PV presented in this patient. Thus, involvement of the back should also be considered for biopsy and histology as atypical locations in PV, such as feet, scalp and abdomen, have also been documented.