Feline Progressive Histiocytosis

Abstract

Abstract. Histiocytic proliferative diseases include reactive and neoplastic proliferations of dendritic cells (DC) or macrophages. Various forms of DC proliferations have been documented in humans and dogs; their etiology is largely unknown. With the exception of a few case reports, histiocytic proliferations have not been characterized in cats. This study summarizes clinical, morphologic, and immunophenotypic features of a feline progressive histiocytosis (FPH) in 30 cats. There was no breed or age predilection. Females were more often affected than males. Solitary or multiple nonpruritic firm papules, nodules, and plaques had a predilection for feet, legs, and face. Lesions consisted of poorly circumscribed epitheliotropic (13/30) and nonepitheliotropic (17/30) histiocytic infiltrates of the superficial and deep dermis, with variable extension into the subcutis. The histiocytic population was relatively monomorphous early in the clinical course. With disease progression, cellular pleomorphism was more frequently encountered. Histiocytes expressed CD1a, CD1c, CD18, and major histocompatibility complex class II molecules. This immunophenotype suggests a DC origin of these lesions. Coexpression of E-cadherin, a feature of cutaneous Langerhans cells, was only observed in 3 cats. FPH followed a progressive clinical course; the lesions, however, were limited to the skin for an extended period of time. Terminal involvement of internal organs was documented in 7 cases. Treatment with chemotherapeutics or immunosuppressive and immunomodulatory drugs was not successful. The etiology of FPH remains unknown. FPH is best considered an initially indolent cutaneous neoplasm, which is mostly slowly progressive and may spread beyond the skin in the terminal stage.

A Review of Histiocytic Diseases of Dogs and Cats

“…The reactive lymphocytes that infiltrate the lesions mostly express CD3 and CD8. 4 Canine Fibrohistiocytic Nodule. The term splenic fibrohistiocytic nodule was introduced in 1998 with the intent of providing useful prognostic information for clinicians and freeing pathologists the burden of deciphering complex splenic lesions of uncertain type.…”

“…76 Most canine and feline histiocytic diseases involve proliferations of cells of LC or interstitial DC lineage; hemophagocytic histiocytic sarcoma (HS) is currently the only histiocytic disease of dogs and cats that has been shown to originate in macrophages. [3][4][5]11,24,51,54 Cytokines and growth factors that influence DC development include fms-like tyrosine kinase (FLT3) ligand, granulocytemacrophage colony-stimulating factor (GM-CSF), stem cell factor, tumor necrosis factor alpha (TNF-a), interleukin 4 (IL-4), and transforming growth factor beta 1 (TGF-b1). 37,76 Macrophage development from CD34þ precursors is influenced by GM-CSF and macrophage colony-stimulating factor (M-CSF).…”

“…These monoclonal antibodies have greatly facilitated the investigation of histiocytic diseases in dogs and cats. [3][4][5]11,18,24,47,51,54 Langerhans cells and dermal interstitial DCs are also distinguishable by their differential expression of E-cadherin (LCsþ) and Thy-1 (CD90) (dermal interstitial DCsþ). Langerhans cells localize within epithelia via E-cadherin homotypic adhesion with E-cadherin expressed by epithelial cells.…”

Primary Nasal Histiocytic Sarcoma of Macrophage–Myeloid Cell Type in a Cat

“…A similar condition in humans is a clonal proliferative disease, but such analysis has not been performed in cats with FPLCH (Willman et al, 1994;Yousem et al, 2001). FPH is a slowly progressive condition in which histiocytes are confined to the skin for extended periods with eventual involvement of internal organs (Affolter and Moore, 2006). Friedrichs and Young (2008) reported a case of feline HS of macrophage origin based on the immunophenotype CD1c À CD11b + CD18 + MHCII + .…”

Disseminated Cutaneous Mast Cell Tumors with Epitheliotropism and Systemic Mastocytosis in a Domestic Cat

“…?show "fnote_aff1"$^! "content-markup(./author-grp [1]/aff|./author-grp [1]/dept-list)> Cutaneous mast cell tumors (MCTs), or mastocytomas, are relatively common dermal or subcutaneous neoplasms that are most commonly found on the head and trunk in cats older than 4 years. 4,11,12,15,17,19,21,22,29 The grading scheme outlined for canine MCTs described previously does not appear to be prognostically significant in cats.…”