muramidase and Tongue-Neoplasms

Fibrous histiocytomas are uncommon mesenchymal tumours of the soft tissue in the head and neck region. We report two cases that occurred in the oral cavity, one of a benign fibrous histiocytoma (BFH) and another of an angiomatoid variant of fibrous histiocytoma (AFH). BFH is a benign neoplasm composed of cells with fibroblastic and histiocytic characteristics, while AFH is considered as a distinct type of fibrous histiocytoma with an intermediate malignancy grade that combines features of both fibrohistiocytic and vascular neoplasm. We describe the clinicopathological and histological characteristics of these lesions to clarify and facilitate their diagnosis. In the BFH case, the surgical specimen had many histiocytes positive for lysozime, whereas the AFH cells showed positivity for endothelial cell marker (anti-CD34 antibody). In both cases the tumours were positive for fibronectin and negative for S100 and SMA. Ki-67. Immunohistochemistry was performed in all cases to reveal the different mitotic activity between AFH and BFH tumour cells. Finally, differential diagnoses and therapeutic treatments are discussed.

Topics: Actins; Adult; Antigens, CD34; Cheek; Diagnosis, Differential; Fibronectins; Histiocytes; Histiocytoma, Benign Fibrous; Histiocytoma, Malignant Fibrous; Humans; Infant; Ki-67 Antigen; Male; Mitotic Index; Mouth Neoplasms; Muramidase; S100 Proteins; Tongue Neoplasms

Six cases of oral granular cell lesions were studied with respect to intermediate-sized filaments (IF), peanut lectin binding (PNL) and muramidase activity by means of the peroxidase antiperoxidase technique. The tumours included three granular cell myoblastomas of the tongue (GCM) two cases of congenital gingival granular cell tumour (CGGT) and one granular cell ameloblastoma (GCA). Every tumour studied showed intracytoplasmic PNL binding whereas muramidase was negative in all cases. Vimentin expression was demonstrated in the CGGT and to a lesser extent in the GCM, but was absent in the GCA which was positive for keratin. Desmin and glial fibrillary acidic protein (GFAP) were not present in any of the lesions. These data demonstrate that PNL binding might be considered to be a common feature of granular cells regardless of their histogenesis. Lysosomes are supposed to represent the intracellular binding sites for this marker. Moreover it is shown that histomorphological identity between the granular cells of CGGT and GCA does not signify identity in histogenesis since the former are of mesenchymal derivation while the latter, from their intermediate filament protein types appear to originate from epithelium.

Topics: Ameloblastoma; Arachis; Gingival Neoplasms; Histocytochemistry; Humans; Intermediate Filament Proteins; Mouth Neoplasms; Muramidase; Neoplasms, Muscle Tissue; Receptors, Mitogen; Tongue Neoplasms; Vimentin