Granulomatosis and Polyangiitis Presenting as Superficial Granulomatous Pyoderma

Abstract

Superficial granulomatous pyoderma (SGP) is one of four subtypes of pyoderma gangrenosum (PG), an uncommon neutrophilic dermatosis, that presents as superficial, indolent ulcerative nodules or plaques that arise independently from an associated underlying disease [1]. Granulomatosis and polyangiitis (GPA) is a systemic, cytoplasmic ANCA (cANCA) positive vasculitis of small and medium vessels classically presenting with a triad of vascular, pulmonary, and renal complications [2]. We report a case of a limited variant of GPA presenting as SGP in a 57year-old male with multiple nonhealing, painful ulcers on the upper extremities, torso, and neck with histologic features of superficial ulcers with predominantly plasma cell infiltrate consistent with atypical SGP. Over the following year, violaceous ulcers appeared, and a larger wedge biopsy demonstrated sinus tract formation with underlying plasmocytosis with histiocytes and giant cells, neutrophilic inflammation, and focal granuloma formation without vasculitis. The patient developed pulmonary symptoms and fever in the setting of markedly elevated cANCA. A chest CT revealed a lung nodule with fine needle aspiration (FNA) demonstrating acute and granulomatous inflammation but no organisms. Based on compatible clinical and histological findings, the diagnosis of GPA presenting as SGP was established. This case of a variant of GPA initially limited to the integument and mistaken for SGP characterizes the clinical and histopathological presentations of two rare diseases and supports the notion that GPA should be included in the differential diagnosis for SGP even before systemic symptoms and elevated cANCA arise to ensure early diagnosis and treatment.

A Rapidly Enlarging Facial Abscess

“…Atypical presentations of granulomatosis with polyangiitis featuring PG-/SGPGlike lesions have been reported, which are sometimes termed malignant pyoderma. 10 In this case, the absence of systemic involvement and negative antineutrophil cytoplasmic antibodies ruled out the diagnosis. Superficial granulomatous PG is a challenging diagnosis requiring a comprehensive workup to rule out mimickers, particularly infections; however, this must be balanced with the need for prompt initiation of immunosuppression in more aggressive cases involving the face that can eventuate in permanent disfigurement.…”

“…The coexistence of granulomas and vasculitis may indicate granulomatosis with polyangiitis, a small-/medium-vessel vasculitis associated with upper/lower respiratory and kidney complications. Atypical presentations of granulomatosis with polyangiitis featuring PG-/SGPG-like lesions have been reported, which are sometimes termed malignant pyoderma . In this case, the absence of systemic involvement and negative antineutrophil cytoplasmic antibodies ruled out the diagnosis.…”

A Rare Form of Granulomatosis With Polyangiitis With Pyoderma Gangrenosum

“…All parts of the body can be affected, however, the most typical presentation includes the upper respiratory tract. It can include recurrence of sinusitis with inflammation that can resemble a severe common cold with persistent rhinorrhea, nasal crusting, nasal congestion or bleeding, as well as ulcerations of mucous membranes [6][7][8]. Another typical organ system involved is the kidneys, in which patients can develop hypertension, and peripheral edema, which can eventually lead to a more serious condition, glomerulonephritis.…”

“…Even rarer presentations include neurological and cardiac abnormalities, ranging from peripheral neuropathy to hemiplegia and pericarditis, cardiomyopathy, and myocardial infarction. Other generalized systemic symptoms include fevers, malaise, polyarthralgia, loss of appetite, and general fatigue [8][9].…”