Abstract：
Granular cell tumors (GCTs) are characterized by abundant eosinophilic cytoplasmic granules. Based on the hypothesis that canine intracranial GCT is a subtype of meningioma and its cytoplasmic granules are formed through autophagy processes, histopathological and immunohistochemical examination were performed on biopsy samples from 7 cases of canine intracranial GCTs and 15 cases of conventional meningiomas. Histopathologically, 7/7 cases of GCTs involved the meninges; foci of meningothelial-like cells were observed in 3/7 cases; brain invasion was observed in 2/7 cases. Immunohistochemically, neoplastic cells of GCTs were positive for E-cadherin and negative for S100, cytokeratin, CD204, and β-catenin in 7/7 cases. Neoplastic cells of 15/15 cases of meningiomas were positive for E-cadherin, and negative for S100 and CD204. Immunoreactivity of meningiomas for cytokeratin and β-catenin was observed in 6/15 cases and 8/15 cases, respectively. Cytoplasmic granules of GCTs were positive for ubiquitin (5/7), p62 (5/7), and LC3 (7/7). Compared to GCTs, the ratios of ubiquitin (6/15) and p62 (3/15) positive cases were lower in meningiomas, and 15/15 cases were negative for LC3. These findings indicate that the biological natures of GCTs including anatomical location, histopathological features and immunoreactivity for E-cadherin are almost in conformity with those of meningiomas. The immunoreactivity for autophagy associated molecules may suggest the possible involvement of autophagy in cytoplasmic granule formation of canine intracranial GCTs.
摘要：
颗粒细胞肿瘤（GCTs）的特征是大量的嗜酸性粒细胞胞浆颗粒。基于假设犬颅内GCT是脑膜瘤的一种亚型，其细胞质颗粒是通过自噬过程形成的，对7例犬颅内GCT和15例常规脑膜瘤的活检标本进行组织病理学和免疫组织化学检查。组织病理学,7/7例GCT累及脑膜；3/7例可见脑膜上皮样细胞灶；2/7例可见脑浸润。免疫组织化学，肿瘤细胞的GCTs是E-cadherin阳性和阴性的S100，细胞角蛋白，7/7例患者中CD204和β-catenin。15/15脑膜瘤的肿瘤细胞E-cadherin阳性，S100和CD204阴性。在6/15例和8/15例中观察到脑膜瘤对细胞角蛋白和β-catenin的免疫反应性。分别。GCT的细胞质颗粒泛素阳性（5/7），P62(5/7),和LC3（7/7）。与GCT相比，脑膜瘤中泛素（6/15）和p62（3/15）阳性病例的比率较低，15/15例LC3阴性。这些发现表明，GCT的生物学性质包括解剖位置，E-cadherin的组织病理学特征和免疫反应性与脑膜瘤几乎一致。自噬相关分子的免疫反应性可能提示自噬可能参与犬颅内GCT的细胞质颗粒形成。
