Pazdzior-Czapula Katarzyna, Mikiewicz Mateusz, Gesek Michal, Zwolinski Cezary, Otrocka-Domagala Iwona
Department of Pathological Anatomy, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Oczapowskiego St. 13, 10-719 Olsztyn, Poland.
Folia Histochem Cytobiol. 2019;57(3):146-154. doi: 10.5603/FHC.a2019.0016. Epub 2019 Sep 25.
Canine cutaneous round cell tumours (CCRCTs) include various benign and malignant neoplastic processes. Due to their similar morphology, the diagnosis of CCRCTs based on histopathological examination alone can be challenging, often necessitating ancillary immunohistochemical (IHC) analysis. This study presents a retrospective analysis of CCRCTs.
This study includes 60 cases of CCRCTs, including 55 solitary and 5 multiple tumours, evaluated immunohistochemically using a basic antibody panel (MHCII, CD18, Iba1, CD3, CD79a, CD20 and mast cell tryptase) and, when appropriate, extended antibody panel (vimentin, desmin, a-SMA, S-100, melan-A and pan-keratin). Additionally, histochemical stainings (May-Grünwald-Giemsa and methyl green pyronine) were performed.
IHC analysis using a basic antibody panel revealed 27 cases of histiocytoma, one case of histiocytic sarcoma, 18 cases of cutaneous lymphoma of either T-cell (CD3+) or B-cell (CD79a+) origin, 5 cases of plas-macytoma, and 4 cases of mast cell tumours. The extended antibody panel revealed 2 cases of alveolar rhabdo-myosarcoma, 2 cases of amelanotic melanoma, and one case of glomus tumour.
Both canine cutaneous histiocytoma and cutaneous lymphoma should be considered at the beginning of differential diagnosis for CCRCTs. While most poorly differentiated CCRCTs can be diagnosed immunohis-tochemically using 1-4 basic antibodies, some require a broad antibody panel, including mesenchymal, epithelial, myogenic, and melanocytic markers. The expression of Iba1 is specific for canine cutaneous histiocytic tumours, and more sensitive than CD18. The utility of CD20 in the diagnosis of CCRCTs is limited.
犬皮肤圆形细胞瘤（CCRCTs）包括各种良性和恶性肿瘤性病变。由于它们形态相似，仅基于组织病理学检查来诊断CCRCTs具有挑战性，通常需要辅助免疫组织化学（IHC）分析。本研究对CCRCTs进行了回顾性分析。
本研究纳入60例CCRCTs，包括55例单发肿瘤和5例多发肿瘤，使用基本抗体组合（MHCII、CD18、Iba1、CD3、CD79a、CD20和肥大细胞类胰蛋白酶）进行免疫组织化学评估，并在适当情况下使用扩展抗体组合（波形蛋白、结蛋白、α -平滑肌肌动蛋白、S - 100、黑素A和泛角蛋白）。此外，还进行了组织化学染色（May - Grünwald - Giemsa和甲基绿派洛宁）。
使用基本抗体组合的IHC分析显示，有27例组织细胞瘤、1例组织细胞肉瘤、18例T细胞（CD3 +）或B细胞（CD79a +）起源的皮肤淋巴瘤、5例浆细胞瘤和4例肥大细胞瘤。扩展抗体组合显示有2例肺泡横纹肌肉瘤、2例无色素性黑色素瘤和1例血管球瘤。
在CCRCTs的鉴别诊断开始时，应考虑犬皮肤组织细胞瘤和皮肤淋巴瘤。虽然大多数低分化CCRCTs可以使用1 - 4种基本抗体进行免疫组织化学诊断，但有些需要广泛的抗体组合，包括间充质、上皮、肌源性和黑素细胞标记物。Iba1的表达对犬皮肤组织细胞性肿瘤具有特异性，且比CD18更敏感。CD20在CCRCTs诊断中的效用有限。
