Palisaded neutrophilic granulomatous dermatitis with leukocytoclastic vasculitis in a patient without any underlying systemic disease detected to date

Non-Infectious Granulomatous Dermatoses: A Pathologist's Perspective

Granulomatous dermatitis (GD) is one of the commonest tissue reaction patterns encountered in dermatopathology practice. Granulomatous inflammation in the skin can be seen in a wide range of conditions, thus, granulomatous dermatitis always poses significant challenge even to the astute dermatologists and dermatopathologists. Broadly, granulomatous dermatitis is divided into two groups-infectious and non-infectious, the prevalence of both highly variable and show overlapping pathology. However, there are subtle histological clues, which when combined with clinical features, help to narrow down the differential diagnosis. Thus, a good Clinicopathological correlation (CPC) along with histochemical stains, culture and ancillary techniques including molecular studies are required for arriving at a definite diagnosis. In this review, we shall discuss the histological clues to diagnose non-infectious granulomatous dermatitis (NIGD) and their differential diagnoses.

Palisaded Neutrophilic and Granulomatous Dermatitis in a Patient with Granulomatosis with Polyangiitis

Palisaded neutrophilic and granulomatous dermatitis (PNGD) shows various clinical features and is histologically characterized by palisaded granulomas surrounding degenerated collagen. PNGD is known to be associated with a variety of systemic conditions such as rheumatoid arthritis and systemic lupus erythematosus. Furthermore, PNGD has been reported to be associated with antineutrophilic cytoplasmic antibody-associated vasculitis, including granulomatosis with polyangiitis (GPA) and microscopic polyangiitis. Here, we report a case of PNGD associated with GPA, which showed the infiltration of CD163-positive M2 macrophages in the skin lesion with elevated serum level of soluble CD163 (sCD163). The serum sCD163 level was reduced to normal range after systemic steroid therapy. Thus, M2 macrophages may play a role in the pathomechanisms of PNGD associated with GPA.

Reactive Granulomatous Dermatitis: A Review of Palisaded Neutrophilic and Granulomatous Dermatitis, Interstitial Granulomatous Dermatitis, Interstitial Granulomatous Drug Reaction, and a Proposed Reclassification

The terms "palisaded neutrophilic and granulomatous dermatitis," "interstitial granulomatous dermatitis," and the subset "interstitial granulomatous drug reaction" are a source of confusion. There exists substantial overlap among the entities with few strict distinguishing features. We review the literature and highlight areas of distinction and overlap, and propose a streamlined diagnostic workup for patients presenting with this cutaneous reaction pattern. Because the systemic disease associations and requisite workup are similar, and the etiopathogenesis is poorly understood but likely similar among these entities, we propose the simplified unifying term "reactive granulomatous dermatitis" to encompass these entities.

Autoimmunity-related granulomatous dermatitis in association with hepatitis

AIM

Both interstitial granulomatous dermatitis (IGD) and palisaded neutrophilic granulomatous dermatitis (PNGD) are rare disorders typically associated with systemic autoimmune conditions. They probably represent different aspects of a disease spectrum encompassing the concept of autoimmunity-related granulomatous dermatitis (ARGD).

CASE REPORT

A 61-year-old woman presented with ARGD and autoimmune hepatitis. The clinical presentation suggested PNGD, while histopathology was consistent with IGD.

DISCUSSION

The association of ARGD with autoimmune hepatitis is apparently a rare event. The present case shows that the clinicopathological correlation in ARGD does not always clearly fit with the classical presentations of IGD or PNGD.