Lingual histiocytic sarcoma in a dog: A case report

An 8-year-old spayed Maltese dog was presented for the evaluation of a lingual mass. The dog had excessive drooling and dysphagia. Oral examination revealed a soft, fluctuating mass at the left side of the tongue. Computed tomography showed a 21 × 32 × 66 mm lingual mass and enlarged left medial retropharyngeal lymph node. On cytology of the lingual mass, a round cell tumor was suspected; however, it was not responsive to glucocorticoid therapy. Because of severe complications, glossectomy and lymphadenectomy were performed; unfortunately, the patient died because of dyspnea in the postoperative period. Histopathologic examination and immunohistochemistry revealed lingual histiocytic sarcoma and confirmed lymphatic metastasis. This is a rare case report of a dog with lingual histiocytic sarcoma diagnosed based on histopathology and immunohistochemistry.