Eosinophilic angiocentric fibrosis (EAF) is a rare tumefactive fibroinflammatory disease with predilection for the upper respiratory tract, mainly the sinonasal cavities [1]. Following its original description by Holmes and Panje in 1983 as intranasal granuloma faciale [2], the currently used term “eosinophilic angiocentric fibrosis (EAF)”, has been coined by Roberts and McCann in 1985 [3]. To date, no >60 cases have been reported in the literature [1], [4], [5], [6], [7].

EAF affects both sexes equally at a wide age range (16 to 79 yrs). Prolonged obstructive sinonasal symptoms, occasionally with associated nasal deformities, are the main presentation and may be present for several years or even decades prior to diagnosis [1], [4], [5], [6], [7]. Destructive involvement of adjacent craniofacial bones may mimic malignancy [8]. Except for rare cases that have been associated with the systemic IgG4-related disease [7] or granulomatosis with polyangiitis [9], EAF is usually not accompanied by any other systemic manifestations of autoimmune or vasculitic disorders.

Histologically, EAF seems to progress through different stages. Focal small vessel eosinophilic vasculitis characterizes the early phase, accompanied by eosinophilic degradation and gradual emergence of increasing numbers of lymphoplasmacytic cells with variable lymphoid follicle formation [1]. The eventual emergence of mainly angiocentric onionskin fibrosis gives the disease its name. Continuous progressive fibrosis accompanied by progressively decreasing inflammatory cells characterizes the late paucicellular stage of the disease [1], [7]. The background fibroblastic cells entrapping obliterated small vessels frequently give a pseudogranulomatous appearance. Notably, necrosis, atypia, mitoses, and well-formed granulomas are definitionally lacking in EAF.

Erythema elevatum diutinum (EED) and granuloma faciale are two variants of immune complex-mediated cutaneous small-vessel vasculitic disorders collectively named “chronic localized fibrosing leukocytoclastic vasculitis” [10], [11], [12]. Acral sites and symmetrical bilateral extensor surfaces (EED) and skin of the face (GF) are the main affected sites [10], [11], [12]. Histologically, these diseases are similar, characterized by small-vessel neutrophilic leukocytoclastic vasculitis. GF also shows admixed eosinophilic reaction. Rarely, EED may present with tumefactive nodular (pseudotumoral) fibrous lesions closely mimicking EAF [12], [13].

Extranasal EAF is very rare and involves mainly head and neck sites (larynx, the orbit, conjunctiva, and lacrimal glands), and the lower respiratory tract and lungs [1], [7], [14]. However, involvement of other sites such as the breast is very rare [15].

In this study, we describe four patients presenting with large fibroinflammatory pseudotumors in the paravertebral region not associated with IgG4-related disease or any autoimmune systemic disorders and showing hybrid features of both EAF and nodular EED.