Salomão D R, Sigman J D, Greenebaum E, Cohen M B
Department of Pathology, the University of Iowa Hospitals and Clinics, Iowa City 52242-1009, USA.
Cancer. 1998 Aug 25;84(4):245-51.
The head and neck region is one of the most common locations of rhabdomyosarcoma. Salivary gland involvement is usually secondary to advanced disease, and presentation as a primary salivary gland tumor is very rare.
Three cases of rhabdomyosarcoma presenting as parotid masses, in 2 boys (ages 3 and 7 years) and a girl (age 5 years), were retrieved from the files of 2 institutions.
The three patients presented with parotid gland enlargement. Clinically, the enlargements appeared to be inflammatory, and they were treated unsuccessfully with antibiotics. Fine-needle aspiration biopsy (FNAB) was performed on all three patients. The cytologic features varied from one case to another; one case had features of a small round cell tumor, another was composed of a monomorphic population of spindle cells in a metachromatic stroma, and the third case was composed mostly of spindle cells with moderate cellular pleomorphism. Immunohistochemical studies performed in two of the cases confirmed the diagnosis of rhabdomyosarcoma, and ultrastructural studies were confirmatory in the other case. The patients are alive; 2 of them have had no evidence of disease after 6 and 9 years of follow-up, and the third, the most recent patient, has just finished adjuvant chemotherapy.
With the increased use of FNAB for the evaluation of salivary gland masses in children, the authors believe that it is important to recognize the occurrence of rhabdomyosarcoma in this location. Immunohistochemical studies have proved helpful in differentiating rhabdomyosarcoma from other parotid gland tumors and can be readily done on cytologic preparations.
头颈部是横纹肌肉瘤最常见的发病部位之一。唾液腺受累通常继发于晚期疾病，而表现为原发性唾液腺肿瘤的情况非常罕见。
从两家机构的档案中检索出3例表现为腮腺肿块的横纹肌肉瘤病例，其中2例为男孩（年龄分别为3岁和7岁），1例为女孩（年龄5岁）。
3例患者均表现为腮腺肿大。临床上，肿大看似为炎症性，使用抗生素治疗无效。对所有3例患者均进行了细针穿刺活检（FNAB）。各病例的细胞学特征各不相同；1例具有小圆细胞瘤的特征，另1例由异染性基质中单一形态的梭形细胞组成，第3例主要由具有中度细胞多形性的梭形细胞组成。对其中2例进行的免疫组织化学研究证实了横纹肌肉瘤的诊断，另一例通过超微结构研究得以确诊。患者均存活；其中2例在随访6年和9年后无疾病证据，第3例，即最近的患者，刚刚完成辅助化疗。
随着FNAB在评估儿童唾液腺肿块中的应用增加，作者认为认识到该部位发生横纹肌肉瘤很重要。免疫组织化学研究已证明有助于将横纹肌肉瘤与其他腮腺肿瘤区分开来，并且可以很容易地在细胞标本上进行。
