Chronic Localized Fibrosing Leukocytoclastic Vasculitis Associated With Lymphedema, Intralymphatic and Intravascular Lymphocytosis, and Chronic Myelogenous Leukemia: A Case Report of Unilateral Erythema Elevatum Diutinum.

One of the pathogenic causes of cutaneous inflammatory pseudotumors is chronic localized fibrosing leukocytoclastic vasculitis (CLFLCV), a vasculitic reaction pattern seen in granuloma faciale (GF), a localized vasculitis, and erythema elevatum diutinum (EED), a generalized vasculitis. Patients with myelodysplastic syndromes (MDSs) are at risk for a diverse spectrum of cutaneous neutrophilic dermatoses such as EED. Herein, we report a 74-year-old man who presented with a large ulcerative, fungating tumor affecting the right flexor ankle caused by CLFLCV. During his workup and management, MDS and Philadelphia chromosome-negative chronic myeloid leukemia was diagnosed. Surgical excision of the inflammatory mass promptly triggered tumor recurrence, whereas antineutrophil therapy (dapsone coupled with hydroxyurea, and prednisone) lead to tumor regression. Histopathologic examination revealed an eosinophilic-rich small-vessel neutrophilic vasculitis associated with storiform and angiocentric fibrosis (GF-like). In the regions of fibrosis, dilated lymphatic and vascular spaces were numerous, some of which were congested with small CD3-positive lymphocytes (intralymphatic and intravascular lymphocytosis). These findings indicate coexisting localized lymphedema. By direct immunofluorescence, IgM and C4d vessel deposits were detected. The pathogenesis of the fibrotic nodules and plaques of CLFLCV is suspected to be due to recurring bouts of immune-complex vasculitis, creating a cycle of vessel damage followed by reparative granulation tissue. Poor lymphatic drainage may be the underlying factor initiating and maintaining recurrent, localized episodes of immune-complex vasculitis and progressive fibrosis. Although his tumor histopathology resembled GF-eosinophilic rich CLFLCV-the clinical context points to a solitary and paraneoplastic case of EED.