A Comparative Pathological Study on Granulomatous Meningoencephalomyelitis and Central Malignant Histiocytosis in Dogs

Abstract

ABSTRACT. Histiocytic proliferative disorders in canine central nervous system (CNS) including granulomatous meningoencephalomyelitis (GME) and malignant histiocytosis were compared pathologically. Lesions of GME mainly existed in the white matter of the cerebr um, brainstem and cerebellum and consisted of characteristic perivascular cuffing, parenchymal granuloma and leptomeningeal infiltrates of mononuclear cells. In malignant histiocytosis, there were two histological patterns, diffuse proliferation of neoplastic histiocytes through the leptomeninges and neoplastic nodule formation in the parenchyma. Neoplastic histiocytes exhibited mild to severe cellular atypia and high ability of invasion into the brain parenchyma. Mitotic and phagocytic figures were also observed. Several histiocytic markers, including lysozyme, α1-antitrypsin and lectin RCA-1, revealed histiocytic origin of both inflammatory and neoplastic cells, however, those were not determinative for the discrimination between GME and malignant histiocytosis. CD3-and PCNA-positive cells existed in the lesions of both diseases. The number of CD3-positive cells in GME tended to be greater than in malignant histiocytosis, while the difference was not statistically significant.

Histiocytic Sarcoma with Central Nervous System Involvement in Dogs: 19 Cases (2006–2012)

“…Although reported relatively infrequently in the veterinary literature,3, 4, 5, 6, 7, 8, 9, 10, 11, 12 HS with CNS involvement is being recognized more frequently. At our institution (NCSU), we were unable to document a case of HS with CNS involvement before 2006, but confirmed 19 cases from 2006 to 2012.…”

“…Although CNS involvement has been recognized in dogs with disseminated (secondary) HS,2, 3 published reports of HS confined to the CNS (primary HS) are uncommon4, 5, 6, 7, 8, 9, 10, 11, 12 and most describe single cases or small numbers of dogs. The purpose of this report is to document the clinical, diagnostic, and pathologic findings as well as treatment and outcome in a larger case series of dogs with a confirmed diagnosis of HS involving the CNS.…”

Morphological Distinction of Histiocytic Sarcoma from Other Tumor Types in Bernese Mountain Dogs and Flatcoated Retrievers

“…This indicates that a canine subtype comparable to human LCH/LCS may also exist. An eccentrically located nucleus was reported in canine HS (6,37,51) and in human HS (41) and IDCS (14). Further research will shed light on possible similarities among human and canine histiocytic tumor subtypes.…”

Distribution of the Inflammatory Lesions in the Central Nervous System of Dogs Affected with Disseminated and Ocular Form of Granulomatous Meningoencephalomyelitis

“…In the dog 2, granulomatous inflammatory changes predominated in the visual system; a lesion in the optic nerve was most severe, suggesting optic neuritis as a primary lesion. An ocular form of GME with severe granulomatous optic neuritis was also reported [4,10]. The dog 2 showed no nervous signs except for blindness.…”

“…Paraffin sections of 3 m-thick were cut and stained with hematoxylin and eosin (HE). Lectin histochemistry with the use of biotinylated lectin Ricinus communics agglutinin I (RCA-1: specific marker for microglia/ macrophage, dilution 1:400) (Vector Laboratory, Burlingame, U.S.A.) [10] was performed on the selected sect i o n s f r o m t h e b r a i n a n d o p t i c n e r v e . Immunohistochemistry with the use of monoclonal antibody to glial fibrillary acid protein (GFAP, dilution 1:500) (DakoCytomation, Glostrup, Denmark) was also performed on sections from the retina.…”