Dear Editor, Gestational intrauterine choriocarcinoma, a malignant tumour of placental trophoblasts, can present symptomatically as uterine enlargement or abnormal bleeding. Cytology is limited in making the initial diagnosis of cervical/uterine choriocarcinoma. 1 Instead, the diagnosis is frequently made by evaluating b human chorionic gonadotropin (b-hCG) serum levels. In our case report, clinical findings along with the cytological and histomorphological features of cervical/uterine choriocarcinoma are described.A 45-year-old woman presented with an 8-month history of abnormal uterine bleeding. Gynaecological examination revealed an enlarged uterus. Computed tomography scan displayed an enlarged uterus with multiple various sized masses in the corpus and a large heterogeneous mass in the uterine cervix. Laboratory investigations showed low haemoglobin and high serum titre of b-hCG (244,000 mIU/ml).Preoperative cervical smears revealed malignant cells intermingled with benign intermediate and superficial squamous epithelium and many neutrophils. The malignant cells, which formed either clusters of cells or were isolated in an inflammatory background, had moderate to abundant cytoplasm. There were a few mononucleated and binucleated cells, and many cells displaying syncytium-like features ( Figure 1a). The nuclei of the malignant cells varied considerably in size; the largest were 5 to 10 times larger than the smallest ones ( Figure 1b). There were a few cells with abundant, irregularly shaped cytoplasm and bizarre nuclei. Some cells showed prominent eosinophilic nucleoli (Figure 2a). The distribution of nuclear chromatin was coarsely granular. Based on the clinical and cytological findings, the diagnosis of choriocarcinoma was entertained.An abdominal hysterectomy was performed. Sectioning of the enlarged uterus revealed one leiomyoma, two ill-defined 3 cm masses with a necrotic and haemorrhagic area in the corpus, and an infiltrative 5 cm mass with foci of haemorrhage and necrosis in the cervix. Microscopically, the uterine and cervical lesions were composed of clusters of cytotrophoblast separated by streaming masses of syncytiotrophoblasts, resulting in dimorphic plexiform patterns in a haemorrhagic and necrotic background (Figure 2b). The tumour cells were positive for both keratin and hCG. The diagnosis of choriocarcinoma was established. The patient underwent chemotherapy and was followed by monitoring serum b-hCG levels that demonstrated a gradual decline in titres.A major challenge in the cytology diagnosis of cervical choriocarcinoma is the exclusion of a primary cervical neoplasm, particularly squamous cell carcinoma. To differentiate choriocarcinoma from squamous cell carcinoma in cervical smears, one should pay attention to the presence of highly atypical cells with abundant cytoplasm, and bizarre nuclei with prominent nucleoli. The cells of choriocarcinoma are usually larger than carcinoma cells, form syncytiumlike structures, and do not produce keratin. The Figure 1. (a) Cervical cytology. Syncyti...