Objective : In Burkitt lymphoma (BL), fat vacuoles can be seen in the cytoplasm in Giemsa-stained sections cytoplasmic vacuoles are also seen in other malignant lymphomas. We examined the correlation between the rate of detection of cytoplasmic vacuoles in sections stained with Giemsa and the positivity rate on adipophilin immunohistochemistry.

Study Design : We performed Giemsa staining and adipophilin immunostaining of sections obtained from 101 patients, with both benign and malignant lesions. In addition, Sudan III staining was performed in a few cases.

Results : Cytoplasmic fat vacuoles were seen in less than 10% of the benign lesions, whereas they were observed in more than 20% of the malignant lesions. Immunohistochemistry for adipophilin was positive in less than 20% of benign lesions, whereas a high percentage of malignant lymphomas showed positive adipophilin reactivity. On Sudan III staining, positive staining were seen in the case of BL, diffuse large B-cell lymphoma (DLBCL) and anaplastic large cell lymphoma (ALCL).

Conclusion : According to the staining results, it may be considered that the cytoplasmic vacuoles are fat vacuoles. In our series, a higher incidence than 20% of lymphocytic cytoplasmic vacuoles on Giemsa staining was observed only in cases of malignant lymphoma ; therefore, cytoplasmic vacuoles occurring at a higher frequency of 20% should suggest the possibility of malignant lymphoma. A large number of cells in BL, DLBCL, ALCL and adult T-cell leukemia/lymphoma were found to contain cytoplasmic vacuoles.

Objective : Rapid tissue sampling to make a definitive diagnosis by combining rapid on-site cytologic evaluation (ROSE) with fine-needle aspiration cytology of lymph nodes was investigated.

Study Design : The subjects were 27 patients who underwent lymph node dissection after fine-needle aspiration cytology of the cervical lymph node. The number of days to lymph node dissection after fine-needle aspiration cytology was investigated and the cyto- and histological diagnoses were compared between before and after the introduction of ROSE.

Results : The number of days to lymph node dissection after fine-needle aspiration cytology was significantly shorter after the introduction of ROSE. On comparison between the cyto- and histological diagnoses, the accurate diagnosis rates were 90 and 88.2% before and after the introduction of ROSE, respectively.

Conclusion : The combination of fine-needle aspiration cytology of a lymph node with ROSE facilitated rapid tissue sampling as needed, which may facilitate prompt treatment.

Objective : Tumor cells of Grade 1-2 follicular lymphoma (FL G1-2) can be difficult to distinguish from non-neoplastic cells in cytology specimens. Therefore, we developed double immunostaining for BCL2 and BCL6 as a tool to differentiate FL G1-2 cells.

Study Design : Cytology specimens from 50 cases, including 35 cases of malignant lymphoma and 15 cases of non-neoplastic lesions, were used for this study. All samples were collected from patients who had undergone surgery and received a final pathological diagnosis at our hospital during the 16-year period from 2000 to 2016. Double immunostaining was performed on the resected specimens.

Results : All eight cases of FL G1-2 and 22 out of the 29 cases of malignant B-cell lymphoma were doubly stained for both BCL2 and BCL6, and were designated as positive. In contrast, all 15 cases with non-neoplastic lesions were negative. Malignant T-cell lymphoma and classical Hodgkin’s lymphoma were negative.

Conclusion : Double immunostaining for BCL2 and BCL6 could be a powerful auxiliary tool for the diagnosis of FL G1-2.

Background : In the present study, we report a rare case of diffuse large B-cell lymphoma, spindle cell variant (Sp-DLBCL).

Case : The patient was a 50’s woman. She consulted our hospital because of the abdominal mass detected by CT at a nearby hospital. Malignant lymphoma was suspected based on the finding of multiple mesenteric lymph node swelling (1 to 4 cm in diameter) detected by CT and an increase of serum soluble IL-2-receptor. The lymph node was biopsied to make a diagnosis. In the cytological examination, malignant lymphoma was suspected, but histologic examination showed numerous atypical spindle shaped cells, being reminiscent of malignant mesenchymal neoplasm. Immunophenotypical analysis revealed CD20 and MUM-1 positivity, and CD10 and BCL6 negativity on the neoplastic cells. Our final diagnosis was made as Sp-DLBCL, non-GCB type. In the background, variable numbers of T-cells and macrophages were admixtured.

Conclusion : Sp-DLBCL is a very rare variant of malignant lymphoma and difficult to make a diagnosis histologically. In this case, cytological examination was useful tool, and it was very important for the pathological diagnosis to demonstrate the tumor cell origin immunophenotypically.

Background : The syncytial variant is a rare variant of classical Hodgkin lymphoma (CHL)-nodular sclerosis subtype. Histologically, this variant shows diffuse or nodular proliferation of large neoplastic cells, therefore, careful attention should be paid to differentiate it from metastatic carcinoma.

Case : The case was that of a female in her 90’s who presented with right axillary lymph node swelling. Although metastatic breast cancer was suspected, imaging studies did not show any mass lesion in either breast. Fine needle aspiration cytology and needle biopsy of the axillary lymph node did not reveal any definite evidence of neoplastic disease. Imprint cytology of the dissected lymph node showed solitary or clustered large atypical cells with prominent nucleoli, mimicking epithelial tumor. The final histologic diagnosis was the syncytial variant of CHL-nodular sclerosis subtype. Immunohistochemistry showed the following results : cytokeratin (−), LCA (−), CD30 (+), and CD15 (+). Epstein-Barr virus mRNA was detected in the tumor cells.

Conclusion : Cytopathologically, the syncytial variant of CHL-nodular sclerosis subtype shows an abundance of large neoplastic cells often occurring in cohesive clusters like epithelial tumor cells. It should be borne in mind in lymph node cytology that this disease might mimic metastatic carcinoma.

Background : Methotrexate is a frequently used medication for rheumatoid arthritis, and several types of lymphomas have been reported as adverse effects of this treatment. We report a rare case of MTX-related lymphoproliferative disorders occurring on the synovial membrane.

Case : The patient was a 62-year-old woman who had been diagnosed as having rheumatoid arthritis 9 years earlier and received treatment with MTX for the previous 8 years. She presented to us with an 8-month history of progressively worsening swelling and sharp pain of the left knee joint. Cytological examination of a synovial fluid specimen from the left knee joint led to the suspicion of methotrexate-associated lymphoproliferative disorders, and the excised synovial membrane was histologically examined.

Conclusion : Cases of MTX-LPD limited to the synovial membrane are very rare, and in the present case, cytological diagnosis was made by immunostaining of cell block samples. Data of 9 cases of MTX-LPD other than the present case filed in the Niigata Prefectural Rheumatism Center were also reviewed.

Background : Merkel cell carcinoma (MCC) is considered to be a rare neuroendocrine tumor originating from the Merkel cell of the skin. It commonly arises in the head and neck region, especially in sun-exposed skin areas or subcutaneous tissue ; however, it can also be found as a metastatic tumor in the lymph nodes. We treated a patient with Merkel cell carcinoma of a lymph node in the parotid gland, who did not exhibit any skin lesions.

Case : A 70-year-old woman presented to us with a history of noticing a swelling in her right neck 15 months earlier. Fine-needle aspiration cytology revealed scattered small atypical cells, in addition to cell clusters exhibiting epithelial adhesion. The atypical cells had fine granular to smudgy chromatin and inconspicuous cytoplasm, similar to the features of a malignant lymphoma. The tumor was finally diagnosed as a Merkel cell carcinoma on the basis of the histological and immunohistochemical findings. No skin lesions were apparent yet.

Conclusion : The characteristic features of MCC, such as the structural pattern of the single cells or cell clusters and the fine granular to smudgy chromatin, are very important cytological features for the diagnosis of MCC in cases where no skin lesions are evident.

Background : Exclusive lung metastasis from prostate cancer is a rare event. In addition, occult prostate cancer identified by lung metastasis as the first presentation is extremely rare. We report herein on a case of prostate cancer with a lung metastasis detected during a follow-up study on gall bladder carcinoma.

Case : A 75-year-old man had undergone an extended cholecystectomy for gall bladder carcinoma 4 years previously. Chest CT revealed small nodular shadows in the left lung. This mass lesion was considered to be a single metastatic deposit from the previous gall bladder carcinoma. Partial resection of the lung by video assisted thoracic surgery was performed. Histological analysis revealed a homogeneous cribriform growth pattern of columnar cells with prominent nucleoli and no stromal components. These features were not consistent with primary lung cancer and metastasis from gall bladder cancer but metastasis from another organ. Detailed histological and immunohistochemical analysis and high serum PSA value were consistent with prostatic origin. A prostate needle biopsy revealed adenocarcinoma (Gleason score 4+4=8). Extensive clinical and radiological examinations revealed no metastasis in organs other than the lung.

Conclusion : We reported this case of occult prostate cancer identified by a solitary pulmonary metastasis as the first presentation to draw attention to a potential cause of diagnostic error.

Background : Pulmonary alveolar proteinosis (PAP) is a relatively rare disease characterized by abnormal accumulation of a surfactant-derived substance in the alveolar spaces and respiratory bronchioles. Herein, we describe the cytological findings of bronchoalveolar lavage fluid (BALF) obtained from 4 cases of PAP diagnosed by BALF cytology.

Cases : BALF cytology and transbronchial lung biopsy (TBLB) were performed to make a definitive diagnosis in 4 patients aged between 20 and 60 years old suspected as having PAP by computed tomography. The BALF appeared mildly to markedly cloudy : the degree of cloudiness varied among the four cases. Cytology showed granular material, globular amorphous material and foamy macrophages, in varying numbers, in all the cases. The BALF was periodic acid-Schiff positive, and also showed positive immunocytochemical staining for surfactant protein A. On the basis of these findings, we were able to make a definitive diagnosis of PAP. The number of macrophages decreased as the PAP progressed. TBLB also demonstrated the alveolar lesions of PAP : accumulation of eosinophilic materials and foamy macrophages in the alveolar spaces.

Conclusion : The cytological findings in BALF of granular material, globular amorphous material and foamy macrophages is quite useful for the diagnosis of PAP. Moreover, we found that the number of macrophages was correlated with disease progression.

Background : Papillary glioneuronal tumors (PGNTs) are characterized by a pseudopapillary architecture associated with areas of compact neuronal elements in different states of maturation. In the updated 2007 WHO classification of tumors of the central nervous system, PGNTs are identified as a distinct entity, typically corresponding to WHO grade I CNS tumors. Until date, there are no reports of the cytological characteristics of PGNTs.

Case : A 32-year-old woman was admitted to Fukuoka University Hospital with a right temporal lobe tumor. Total resection of the tumor was performed via a right temporo-parietal craniotomy. Intraoperative cytology showed perivascular astrocytes with round to oval nuclei and short cell processes, as well as larger ganglion-like cells and neuronal cells. On the basis of these cytological features, possible glioneuronal tumor was suspected. Postoperative histological examination of the resected specimen revealed a complex pseudopapillary architecture of the tumor. Thickened hyalinized vascular walls were lined by a single layer of small, regular astrocytes, accompanied by proliferating neuronal cells with round nuclei and clear cytoplasm arranged in sheets between the pseudopapillae, which led to the diagnosis of PGNT.

Conclusion : In retrospect, the intraoperative cytological findings were sufficient to make the diagnosis of PGNT. This was an important educational case, demonstrating that even rare glioneuronal tumors can be diagnosed during operation using appropriate cytological techniques.

A possible cytological classification of koilocytosis in cervical cytology was proposed by comparison to the results of high-risk group HPV-DNA test. We used cervical cytology slides with koilocytosis obtained from 39 HPV-positive and 12 HPV-negative patients. According to the cytological features, the koilocytes were divided into 2 types (type Ⅰ and type Ⅱ). Type Ⅰ koilocytes showed a clear perinuclear hallow. Type Ⅱ koilocytes showed bizarre nuclei and relatively high N/C ratios. Our results suggest that type Ⅱ koilocytes appear frequently in high-risk HPV-positive cases.