Objective : Endometrial cytology is an important tool for the diagnosis of endometrial malignancies. The Osaki Study Group reporting format (OSGF) is a new reporting format for endometrial cytology, and its usefulness over the conventional reporting format (CRF) remain unknown. We compared the CRF and OSGF in terms of their diagnostic accuracy for endometrial malignancies.

Study Design : We examined 100 cases of liquid-based cytology (Sure Path) according to the CRF and 121 liquid-based cytology specimens according to the OSGF, and compared the diagnostic accuracy between the two reporting systems. Next, we reclassified the CRF cases according to the OSGF, and compared the diagnostic accuracies of the two formats for the same samples. In addition, we compared the biopsy rate that followed the cytology findings reported according to the CRF and OSGF.

Results : The diagnostic sensitivity (97.1% vs. 63.3%, p<0.01) and specificity (98.6% vs. 85.1%, p<0.01) were higher for OSGF than for CRF. The diagnostic sensitivity in the cases reported by the CRF improved when the findings were reclassified according to the OSGF. The post-report biopsy rate was significantly lower in the OSGF group than in the CRF group (p<0.01).

Conclusion : The OSGF is a more useful format for the diagnosis of endometrial malignancies than the CRF used in conventional clinical practice.

Background : Basal cell carcinoma (BCC) is a malignant skin tumor that rarely metastasizes. Herein, we report a case of BCC of the vulva, especially focusing on the cytological findings.

Case : An 82-year-old female patient presented to our hospital with a painless ulcerated lesion in the vulval area measuring approximately 5 cm in size. Biopsy and cytological examination revealed the characteristic features of BCC. Local excision of the lesion was performed. In the cytological examination performed prior to the operation, pleomorphism with cellular atypia and peripheral palisading were observed ; these findings were similar to the findings in sections prepared from the resected specimen.

Conclusion : In this case, we examined the correlation between the cytological and pathological characteristics. Although the usefulness of cytology for the diagnosis is unknown, when there is strong clinical suspicion of BCC, cytological examination is useful to confirm the diagnosis. Thus, cytological analysis is useful not only to diagnose BCC, but also to distinguish it from other forms of malignant melanoma.

Background : Granular cell tumors are relatively rare tumors originating from Schwann cells that can occur anywhere in the body. Herein, we report a case of granular cell tumor arising in the axillary region, which was difficult to distinguish from metastatic breast cancer.

Case : A 47-year-old woman underwent partial mastectomy, sentinel lymph node biopsy, and radiation therapy for right upper outer quadrant breast cancer. After 5 years, she presented with a subcutaneous mass in the right axilla with a maximum diameter of 1.0 cm, and lymph node recurrence was suspected. Fine-needle aspiration cytology revealed a small number of spindle-shaped cells with coarse and abundant cytoplasmic granules. These cells were difficult to differentiate from apocrine metaplastic cells or apocrine carcinoma cells, but the tumor was eventually diagnosed as a granular cell tumor by core needle biopsy.

Conclusion : Granular cell tumors, composed of cells containing abundant and granular cytoplasm, should be considered in the differential diagnosis of breast tumors, because they can arise in any organ of the body. Trauma associated with the surgery and radiation therapy may have contributed to the development of granular cell tumor in our patient.

Background : We encountered a case of low-grade fibromyxoid sarcoma (LGFMS) as a hybrid tumor with sclerosing epithelioid fibrosarcoma (SEF).

Case : A man in his 50 s presented to us with an axillary mass, which was removed by operation. The cytological features were as follows : atypical cells with spindle- or oval-shaped nuclei were found in a myxoid background that showed metachromasia on Giemsa staining. The cellularity of the clusters was not very high, and mitotic figures were unclear. We suspected that the mass was a benign, or at most low-grade malignant, mesenchymal tumor, but were unable to list possible histological types in the differential diagnosis. Finally, on histopathology, the tumor showed two histological types, both of which showed positive immunohistochemical staining for MUC4. The cytological features that we observed in this case were consistent with the diagnosis of LGFMS.

Conclusion : The histological features were reflected in the cytological findings of this case. Giemsa staining was helpful for the diagnosis of this condition. Thus, Giemsa staining, in addition to Papanicolaou staining, is useful for delineating the cytological features of soft tissue tumors.

Background : Pleomorphic adenoma of the salivary gland associated with necrosis is rare. Findings of fine-needle aspiration (FNA) cytology in one such case is reported.

Case : A male patient in his 40’s presented with the complaints of swelling and pain in the left submandibular gland. Findings of ultrasonography were suggestive of malignancy. FNA showed numerous large cells with nuclear atypia, naked nuclei and multinucleated cells in the background of a large amount of necrosis and inflammation. However, no myxomatous stroma was found. Therefore, malignancy could not be ruled out. Extensive coagulative necrosis and abscess formation were observed at the center of the tumor. In addition, organization and fibrous connective tissue were seen around the tumor. In a part of the margin of the tumor, structures composed of epithelial or myoepithelial cells were observed which showed cord-like, nest-like, glandular or tubular arrangement. Based on the findings, the tumor was diagnosed as a pleomorphic adenoma with a large area of infarct-like necrosis.

Conclusion : In this case, the possibility of malignant tumor could not be ruled out because of the presence of necrosis, and histiocytes/fibroblasts with reactive atypia. Cytologists should be aware of the cytological findings associated with infarct-like changes of a tumor and exercise adequate caution while diagnosing a tumor as benign or malignant.

Background : Invasive lobular carcinoma sometimes presents cytologically with cells containing intracytoplasmic mucin and having signet ring cell-like features. Metastases from invasive lobular carcinoma may be difficult to distinguish from primary gastric carcinoma. We report a case of invasive lobular carcinoma in which ascitic fluid showed cells with signet ring cell-like features.

Case : A woman in her 50 s, who had undergone surgery for breast cancer at another hospital 4 years earlier, presented to our hospital with a history of abdominal distension. Based on the findings of endoscopy and abdominal CT, the patient was suspected as having type 4 advanced gastric cancer, ascites and carcinomatous peritonitis. Cytologic examination of the ascitic fluid revealed scattered univacuolated signet ring-like cells containing mucin. The atypical cells were small and monomorphic in shape, and showed a high N/C ratio with uniform linear arrays. The cells had thick light-green cytoplasm, increased fine chromatin, and distinct nucleoli, and the diagnosis of poorly differentiated adenocarcinoma was made. The patient was finally diagnosed as having metastasis from lobular carcinoma of the breast to the greater omentum and stomach.

Conclusion : The presence or absence of linear arrays of tumor cells and nuclear pleomorphism, nuclear size, and the ratio of multivacuolated cells among signet ring-like cells in the ascitic fluid are considered to be useful to distinguish invasive lobular carcinoma from poorly differentiated gastric adenocarcinoma.

Background : Angiomyolipoma (AML) is a benign tumor consisting of three components, namely, blood vessels, smooth muscles, and adipocytes, that rarely arises in the liver. Two cases of AML of the liver are reported, with a special focus on the cytological features.

Case S : Case 1 : A woman in her forties. Fine needle aspiration cytology (FNAC) revealed giant atypical cells with naked nuclei, in bizarre shapes, containing clear nuclei. Spindle-shaped cells formed blood vessel-like structures. Based on these findings, malignancy could not be excluded. Case 2 : A woman in her sixties. FNAC revealed three components : giant atypical cells with clear nuclei, adipocytes, and spindle cells. Histologically, we recognized adipocytes, blood vessels, and a variety of giant atypical cells.

Conclusion : AML is a benign tumor composed of giant atypical cells. Caution should be exercised against misdiagnosing it as a malignant tumor. The giant atypical cells show a variety of characteristic cytological features. In case these findings were seen, AML cannot be excluded. This is one of the pitfalls of liver cytology.

Herein, we report the case of an elderly male patient who was diagnosed as having invasive micropapillary carcinoma (IMPC) of the breast, focusing on the findings of cytology and X-chromosome analysis. The patient presented with a localized solid nodule in the right subareolar region. Cytology revealed cell clusters showing an inside-out pattern in a clean background. The margins of the cell clusters were partially fluffy or showed a microvilli-like pattern. Histologically, the tumor was a combination of invasive ductal carcinoma and IMPC. FISH assay revealed an increase in the number of X chromosomes in 32% of the tumor cells.