Case 1: A vesiculobullous and ulcerative lesion due to a suprabasilar split of squamous epithelium
Note the tombstone row of basal cells still attached to the dermal papillae. The altered mucosa is thrown into papillary folds and contains a brisk lymphocytic infiltrate.
Case 2: A clue that this is a mucosal biopsy is that we see muscle (to the right). Furthermore, there is no granular layer or keratosis, however, these features can be present if the mucosa is rubbed or irritated. Acantholysis and inflammation are clearly present.
At higher power, one can see the suprabasilar clefting that characterizes this entity.
Yet another lovely photo demonstrating the suprabasilar clefting, which creates the so-called tombstone basal layer.
Pemphigus is a group of serious autoimmune diseases characterized by cutaneous and/or mucosal blistering, due to circulating IgG antibodies directed against desmoglein 1 and 3 (Dsg 1 and 3). There is a fairly strong genetic background to pemphigus with linkage to HLA class II alleles and ethnic groups such as those of Mediterranean and Indian origin.
Pemphigus vulgaris is the most common type of pemphigus. Other subtypes include pemphigus foliaceus, paraneoplastic pemphigus, pemphigus vegetans and IgA pemphigus.
Pemphigus vulgaris affects the mouth at an early stage. Blisters, which eventuate in chronic erosions and ulcers, are seen largely in the buccal mucosa, palate and ventrum of tongue and lips (Scully). Advanced signs usually consist of severe desquamative or erosive gingivitis, and gingival lesions are uncommon at the onset but may appear as isolated blisters (Scully).
Biopsy of perilesional tissue with immunostaining is neceessary for diagnosis. Immune deposits (IgG and C3) are seen intercellularly, and this finding precedes the appearance of squamous acantholysis in the suprabasal epithelium, and so it is more sensitive than conventional histopathology. Assay of serum antibody titres are also useful.
Systemic immunosuppression using corticosteroids, with azathioprine or other adjuvants or alternatives are employed.
This is potentially lethal condition, so systemic immunosuppression is almost invariably required for treatment. Systemic corticosteroids can reduce the mortality to less than 10% (Mignogna).
→Key histologic features include acatholysis, intraepidermal vesicles, "tombstone row" of basal cells due to suprabasilar clefting, and perivascular lymphocytes.
→Pemphigus vulgaris is a result of autoantibodies to cell surface adhesion molecules of keratinocytes, specifically desmoglein 1 and 3.
Scully C, Mignogna M. Oral mucosal disease: pemphigus. Br J Oral Maxillofac Surg. 2008 Jun;46(4):272-7.
Mignogna MD, et al. Oral pemphigus: long term behaviour and clinical response to treatment with deflazacort in sixteen cases, J Oral Pathol Med 29 (2000), pp. 145–152.