Objective : Liquid-based cytology (LBC) is widely used worldwide to standardize specimen preparation. ThinPrep^® is the most commonly applied specimen preparation method for LBC. Therefore, evaluation of slides prepared using ThinPrep^® and the preparation process are meaningful. In the present study, we determined the minimum number of cells required to detect malignant cells on LBC slides prepared using ThinPrep^®.

Study Design : Specimens were prepared by mixing 5000, 500, 50, or 5 HeLa cells as malignant cells with 500000 squamous (oral) cells. LBC examination was performed after Papanicolaou staining, and the number of malignant cells on the slides were counted.

Results : Malignant cells could be detected in all the slides prepared from specimens containing 5000, 500, or 50 HeLa cells mixed with 500000 squamous cells. However, malignant cells could be detected only from some of the slides made from specimens containing 5 HeLa cells mixed with 500000 squamous cells.

Conclusion : Detection of malignant cells in specimens prepared using ThinPrep^® requires the presence of more than 50 malignant cells in the specimen.

Background : We report a case of adenosquamous carcinoma, the so-called “glassy cell carcinoma (GCC)” of the uterine cervix, coexisting with small cell carcinoma.

Case : A woman in her thirties presented to us complaining of abnormal vaginal bleeding. We performed a direct cervical smear cytology, which revealed atypical cells with small, naked nuclei and fine granular chromatin, as well as atypical cells with large nuclei and distinct nucleoli in a sheet-like arrangement. The suspected cytopathological diagnosis was small cell carcinoma coexisting with adenocarcinoma. A biopsy revealed features of an invasive carcinoma with neuroendocrine differentiation. We diagnosed the patient as having clinical stage IB2 cervical cancer and performed total hysterectomy. Histopathology of the surgically resected specimen revealed GCC with a small cell carcinoma component. No metastases were found in the dissected pelvic lymph nodes, and the pathological disease stage was determined as pT1b1N0M0. The patient was administered postoperative chemotherapy, and no recurrence or metastasis was observed until the last examination conducted six years after the surgery.

Conclusion : Although GCC is rare, recognizing that this histology can be encountered in clinical practice is important. When the cytological features do not fully satisfy the criteria for adenocarcinoma or squamous cell carcinoma, the possibility of GCC should be considered. Also, coexistence of multiple histological types is frequently observed in cervical small cell carcinoma. A careful examination of cytopathological specimens is crucial, because small cell carcinoma cells can coexist with a non-small cell carcinoma component.

Background : We present a case of uterine leiomyoma with bizarre nuclei (LBN).

Case : A woman in her forties presented to her doctor with prolonged menstruation and was diagnosed as having a uterine leiomyoma. Over time, the tumor grew to 40 mm in diameter, and the patient was referred to our hospital. Magnetic resonance imaging showed multiple masses in the uterus. Intraoperative rapid diagnosis was performed to distinguish between benign and malignant tumor. Imprint cytology revealed large atypical cells, containing pleomorphic nuclei with degenerative-like chromatin. Nuclear inclusions were present, nucleoli were prominent, and the cell cytoplasm was either lightgreen or not clearly visible. Histologically, bizarre spindle-shaped cells resembling smooth muscle cells were observed. The atypical cells were large, pleomorphic, and contained eosinophilic cytoplasm with occasional nuclear inclusions. No mitotic figures or tumor necrosis were observed. Immunohistochemical analysis revealed diffuse positivity for p16, partial positivity for p53 (wild-type pattern), and a Ki-67 index of less than 1%.

Conclusion : In cases where atypical cells suggestive of leiomyosarcoma are observed, cytological assessment for the presence or absence of tumor necrosis, mitotic figures, and degenerative-like smudged nuclear chromatin can help confirm the diagnosis of LBN.

Background : Lung epithelioid hemangioendothelioma (EHE) is a rare vascular neoplasm, and diagnosis by cytology is often challenging. We report a case of EHE diagnosed by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) biopsy. We also reviewed the cytology slides and found metachromatic mucous material by May-Giemsa staining.

Case : A 50s-year-old woman underwent EBUS-TBNA of a left hilar mass. Cytologic examination showed loosely cohesive clusters of epithelioid cells containing irregular nuclei with nucleoli and intracytoplasmic vacuoles. These cytologic findings suggested adenocarcinoma, however, histopathology revealed positive results for endothelial markers, and the final pathological diagnosis was EHE. We reevaluated the cytological findings and found metachromatic myxoid material by May-Giemsa staining of the sections.

Conclusion : The cytological features of this case were similar to those of adenocarcinoma, making differentiation between the two difficult. Detection of metachromatic interstitial mucus is useful for the diagnosis of EHE.

In this article, we present a case of a parotid gland nodule, in which the aspiration cytology specimen showed amylase crystalloids. The patient, a woman in her 70 s, diagnosed as having a nodule in the left parotid region, was referred to our otolaryngology department. Imaging revealed a well-demarcated nodule measuring approximately 20 mm in diameter. Aspiration cytology showed a large number of crystalloids with inflammatory cells. Immunocytochemically, these crystalloids were positive for α-amylase. It is important to consider the possibility of amylase crystalloids in cases where the aspiration cytology specimens show crystalloids of various shapes.

Background : Primary sclerosing cholangitis (PSC) is a rare disease with a poor prognosis.

Case : Herein, we present the case of a male patient in his 30 s with ulcerative colitis, who presented to us with abnormal liver function test results, elevated biliary enzyme levels, and prominent biliary strictures. We confirmed the diagnosis of PSC by liver biopsy. While the initial biliary cytology was benign, atypical cells were found in the subsequent cytology specimen. We considered adenocarcinoma of the bile duct in the differential diagnosis. However, there was no prominent hyperchromasia and the cytology was classified as suspicious.

Conclusion : Bile duct brushing cytology by endoscopic retrograde cholangiopancreatography (ERCP) could play a critical role in the diagnosis of PSC.