Background : In patients with fallopian tube carcinoma, cancer cells can be detected on endometrial cytology.

Case : The patient was a 56-year-old woman who presented with massive ascites and parasternal lymphadenopathy and masses in the peritoneum, left ovary, and uterine corpus. Findings of endometrial cytology suggested ovarian, fallopian tube, or peritoneal cancer rather than endometrial cancer. After administering two courses of chemotherapy, we performed laparoscopic bilateral salpingo-oophorectomy and hysteroscopic biopsy of the endometrium and myometrium. Postoperative histopathology revealed serous tubal intraepithelial carcinoma in the right fallopian tube. Endometrial histopathology revealed small clusters of adenocarcinoma cells not contiguous with the normal endometrium, which suggested metastasis to the myometrium. We administered four additional courses of chemotherapy, followed by hysterectomy and omentectomy. Postoperative histopathology revealed high-grade serous carcinoma in the myometrium and omentum, but no tumor cells in the endometrium. The final histopathological diagnosis was stage ⅣB right fallopian tube carcinoma with myometrial metastasis.

Conclusion : Endometrial cytology revealing small clusters of atypical cells with normal endometrial cells in a normal background should raise the suspicion of fallopian tube carcinoma.

Background : Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare tumor derived from the precursors of plasmacytoid dendritic cells, and needs to be differentiated from acute monocytic leukemia (AMoL). Herein, we report the cytomorphological findings in two cases of BPDCN and compare them with those in AMoL.

Cases : Case 1 was a male patient in his 60s who presented with generalized erythema, and Case 2 was a male patient in his 70s who presented with subcutaneous induration in the right hypochondrium. Both patients underwent skin biopsies and lymph node needle biopsies. In both cases, the imprint cytology of lymph node needle biopsies showed tumor cells with pseudopodia. On Giemsa staining, the cytoplasm of the tumor cells was grayish blue in color and contained small vacuoles ; however, the characteristic granules observed in AMoL were not present. Immunohistochemical staining of skin biopsy samples from both patients were positive for CD4, CD56, CD123, TCL1, and CD303 ; on the findings, both cases were diagnosed as having BPDCN.

Conclusions : BPDCN is a closely related neoplasm to AMoL, but treatment strategies for the two diseases are different. It is important to differentiate BPDCN from AMoL based on the findings of pseudopodia and lack of granules on Giemsa staining in the tumor cells in cytology specimens that can be quickly prepared, and to make an early diagnosis by marker search.

Background : We report a case of paraganglioma of the bladder detected by bladder washing cytology (BWC).

Case : A male in his 50s. A bladder tumor was detected at another hospital, but it was followed up as a benign tumor. The patient was referred to our hospital when he developed hematuria and signs of tumor growth. BWC revealed cells that were different in appearance from those in typical high-grade urothelial carcinoma, or umbrella cells. The cytological diagnosis was suspicious (atypical cells of unknown origin). Cystoscopy revealed a submucosal tumor-like mass on the posterior wall. Transurethral bladder tumor resection (TUR-BT) was performed, and the histopathological diagnosis was primary paraganglioma of the bladder.

Conclusion : The cytological characteristics observed on BWC in our case were as follows : 1) Tumor cells with a high N/C ratio and fine granular cytoplasm were observed in small clusters or as scattered cells ; 2) the nuclei were round with fine chromatin and inconspicuous nucleoli ; and 3) there were binucleated cells and multinucleated cells.

Background : Anaplastic thyroid carcinoma is a rare, but highly malignant disease. Herein, we report a case of anaplastic thyroid carcinoma that showed a variety of cytological findings on fine-needle aspiration cytology.

Case : A female patient in her 60s presented to our hospital with a rapidly enlarging neck mass. Cervical computed tomography and cervical ultrasonography revealed a mass in the right lobe of the thyroid gland and an enlarged right cervical lymph node, both of which were suspected as being malignant. Fine-needle aspiration cytology (FNAC) of the mass in the thyroid gland revealed keratinized atypical cells, which led to the suspicion of squamous cell carcinoma. Postoperative histopathological examination of the excised thyroid gland exhibited features of both papillary and anaplastic thyroid carcinomas, and the final diagnosis was anaplastic thyroid carcinoma with squamous differentiation. A review of the cytology findings revealed papillary carcinoma components, diverse multinucleated giant cells, and neutrophilic infiltration within highly atypical cell clusters.

Conclusion : When keratinizing atypical cells are found on FNAC, conditions that should be considered in the differential diagnosis include anaplastic carcinoma with squamous differentiation, squamous metaplasia of papillary carcinoma, intrathyroidal thymic carcinoma, sclerosing mucoepidermoid carcinoma with eosinophilia, and diffuse sclerosing papillary carcinoma. Anaplastic carcinoma with squamous differentiation is presumed when necrotic and inflammatory cells are seen in the background, and large atypical cells with various morphologies and mitoses are seen.

Background : Spindle cell rhabdomyosarcoma (Sp-RMS) is a rare tumor arising in the head and neck region. We report a case of Sp-RMS of the left parotid gland that was detected after surgery for myoepithelial carcinoma (MC) of the left parotid gland.

Case : The patient was a 30-year-old woman. MRI and PET-CT showed a mass in the postoperative area, and aspiration cytology was performed. The tumor cells contained spindle-shaped nuclei, with some cytoplasmic inclusion bodies in the nuclei and rhabdomeres in the cytoplasm. In addition, caudal rhabdomyoblasts were observed. Histological images showed spindle-shaped tumor cells proliferating in bundles or in intricate structures. Immunohistochemical analysis revealed positive staining of the tumor cells for desmin, HHF35, myogenin, and myoD1, and negative staining for S-100a, AE1/AE3, αSMA, and calponin, leading to the diagnosis of Sp-RMS.

Conclusion : Presence of cytoplasmic inclusion bodies in the tumor cell nuclei, and presence of rhabdomyoblasts and intracytoplasmic striations may suggest the diagnosis of Sp-RMS.