A diffuse polymorphous inflammatory infiltrate is present in the dermis. There is a distinct Grenz zone present in the upper right hand corner of the picture. One can also appreciate fibrosis throughout the dermal layer, which is a common finding in more mature lesions.
A high power view better demonstrates the eosinophilic infiltrate, vasculitis, and fibrosis.
Granuloma faciale (GF) is a rare chronic inflammatory dermatoses of unknown etiology. It is suspected that a type III hypersensitivity reaction (Arthrus-like process) is involved as immunofluorescence studies have shown immunoglobulin complexes within vessel walls.
Histologic examination shows a diffuse dermal infiltrate of lymphocytes, neutrophils, plasma cells, and eosinophils. There is typically a distinct Grenz zone as the infiltrate does not involve the papillary dermis. GF has a similar histologic appearance as erythema elevatum diutinum (EED), and therefore should be kept in the differential; however, EED typically lacks a prominent eosinophilic infiltrate and Grenz zone. Additionally, the clinical presentation should aid in differentiating these two processes.
Patients are generally asymptomatic and present with a single, smooth, red-brown to purple thickened papule or plaque on the face. In about one third of patients there may be multiple facial lesions and more rarely extrafacial involvement. Middle-aged Caucasian males are most commonly affected by GF.
There is no reliably efficacious therapy for GF, but patients may respond to topical or intralesional cortiocosteroids, oral dapsone, topical tacrolimus, PUVA, and pulse dyed laser therapy.
Although GF is typically asymptomatic and not associated with a systemic disease, patients generally request treatment given the lesion is almost always located on the face. Unfortunately, response to therapy is variably and generally not curative.
Bolognia JL, Jorizzo JL, Rapini RP, eds. Dermatology. St. Louis, MO: Mosby; 2008.
Busam KJ. Dermatopathology: Foundations in Diagnostic Pathology 1st Ed. Philadelphia, PA: Elsevier; 2010.