Heintz P W, Schmidt W A, Pommier R F, Vetto J T, DiTomasso J P
Department of Pathology, Oregon Health Sciences University, Portland, USA.
Acta Cytol. 1998 Nov-Dec;42(6):1431-6. doi: 10.1159/000332180.
Carcinoma ex pleomorphic adenoma is a rare neoplasm of the salivary gland. This lesion, also known as malignant mixed tumor, occurs when a malignant tumor arises in the epithelial component of a pleomorphic adenoma. Reports of fine needle aspiration biopsy (FNAB) diagnosis of malignant mixed tumors are rare and have been limited to cases arising in the parotid. Cytologic features and diagnostic pitfalls of this uncommon neoplasm are presented.
A 75-year-old male presented with a nontender submandibular mass. The lesion had been present 12 months, with a recent increase in size. FNAB was performed, and the smears revealed a mixture of benign and malignant areas. The benign portion of the smears showed findings typical of pleomorphic adenoma. The malignant area showed large cells occurring singly and in groups. The malignant cells contained pleomorphic nuclei with irregular nuclear membranes and prominent macronucleoli; cytologically, they resembled cells from a poorly differentiated adenocarcinoma.
We present the first case of carcinoma ex pleomorphic adenoma of the submandibular gland correctly diagnosed by FNAB. This rare salivary gland malignancy can be accurately diagnosed on FNAB if strict criteria are applied.
多形性腺瘤恶变是一种罕见的涎腺肿瘤。这种病变，也称为恶性混合瘤，是在多形性腺瘤的上皮成分中出现恶性肿瘤时发生的。细针穿刺活检（FNAB）诊断恶性混合瘤的报道很少，且仅限于腮腺发生的病例。本文介绍了这种罕见肿瘤的细胞学特征及诊断陷阱。
一名75岁男性患者，下颌下出现无痛性肿块。该病变已存在12个月，近期体积增大。进行了FNAB，涂片显示有良性和恶性区域混合存在。涂片的良性部分显示出多形性腺瘤的典型表现。恶性区域可见单个及成群的大细胞。恶性细胞含有多形性核，核膜不规则，有明显的大核仁；在细胞学上，它们类似于低分化腺癌的细胞。
我们报告了首例通过FNAB正确诊断的下颌下腺多形性腺瘤恶变病例。如果应用严格的标准，这种罕见的涎腺恶性肿瘤可在FNAB上得到准确诊断。
