N. Ohori - Academia.edu (original) (raw)

Papers by N. Ohori

Research paper thumbnail of Contribution of molecular testing to thyroid fine-needle aspiration cytology of "follicular lesion of undetermined significance/atypia of undetermined significance

Cancer cytopathology, Jan 25, 2010

BACKGROUND: ''Follicular lesion of undetermined significance/atypia of undetermined significance'... more BACKGROUND: ''Follicular lesion of undetermined significance/atypia of undetermined significance'' is a heterogeneous category of cases that cannot be classified into 1 of the other established categories. The use of ancillary molecular studies has not been widely explored for this diagnosis. METHODS: All thyroid cytology cases diagnosed as follicular lesion of undetermined significance/atypia of undetermined significance were retrieved from April 2007 to December 2008. During this time period, samples were collected routinely at the time of aspiration for cytologic and molecular studies. Analysis for BRAF and RAS gene mutations and RET/PTC and PAX8/PPARc gene rearrangements were performed and correlated with the cytologic features and surgical pathology outcome. RESULTS: From a total of 513 follicular lesion of undetermined significance/atypia of undetermined significance cases identified, 455 had adequate molecular results. Of these, 117 cases had cytologic-histologic correlation. In this group, 35 (29.9%) cases had a neoplastic outcome and 20 (17.1%) cases from 19 patients were carcinoma. Positive molecular results were found in 12 cases, all of which were papillary carcinoma. There were no false-positive molecular results. In correlating the molecular results with surgical pathology outcome, we found that the cancer probability for follicular lesion of undetermined significance/atypia of undetermined significance cases with molecular alteration was 100%, while the probability for follicular lesion of undetermined significance/atypia of undetermined significance cases without molecular alteration was 7.6% (P < .001). CONCLUSIONS: By cytomorphology alone, follicular lesion of undetermined significance/atypia of undetermined significance specimens represent cases that are intermediate in risk between the benign and ''suspicious for follicular neoplasm'' categories. Although not all papillary carcinoma cases are detected by molecular testing, a positive molecular test result is very helpful in refining follicular lesion of undetermined significance/atypia of undetermined significance cases into high-risk and low-risk categories.

Research paper thumbnail of Primary pleural effusion posttransplant lymphoproliferative disorder: Distinction from secondary involvement and effusion lymphoma

Diagnostic Cytopathology, 2001

Pleural effusion presentation of posttransplant lymphoproliferative disorder (PTLD) is relatively... more Pleural effusion presentation of posttransplant lymphoproliferative disorder (PTLD) is relatively uncommon. Most examples of effusion-based PTLD have been secondary to widespread solid organ involvement, and are associated with an aggressive clinical course. We report on a case of primary effusion PTLD in a 70-yr-old male liver transplant recipient with a history of hepatitis B infection. Cytomorphologically, the pleural fluid specimen showed a monomorphous population of intermediate to large-sized transformed lymphoid cells, with irregular multilobated nuclear contours and readily identifiable mitotic figures. Flow cytometric immunophenotypic studies revealed a CD5-negative, CD10-negative, lambda immunoglobulin light chain-positive, monoclonal B-lymphocyte (CD19-positive/CD20-positive) population. The immunocytochemical stain for CD30 antigen was negative. In situ hybridization study for Epstein-Barr virus (EBV) early RNA (EBER) and Southern blot analysis for EBV terminal repeat sequences were both positive. Southern blot analysis for human herpes virus-8 (HHV-8) was negative. No solid-organ PTLD was identified, and the cytologic results supported the diagnosis of primary effusion PTLD. Immunosuppression was decreased, and 8 mo following the diagnosis of pleural fluid PTLD, the patient was stable and his pleural effusion had markedly diminished. Recognition of primary effusion PTLD and its distinction from PTLD secondarily involving the body fluids and from other lymphomas is important, since the behavior and prognosis appear different.

Research paper thumbnail of Flow Cytometric Immunophenotyping of Cerebrospinal Fluid Specimens

American Journal of Clinical Pathology, 2011

Flow cytometric immunophenotyping (FCI) is recommended in the evaluation of cerebrospinal fluid (... more Flow cytometric immunophenotyping (FCI) is recommended in the evaluation of cerebrospinal fluid (CSF) specimens for hematologic neoplasms. This study reviewed FCI of CSF specimens collected for primary diagnosis (n = 77) and follow-up for known malignancy (n = 153). FCI was positive in 11 (4.8%) of 230 specimens: acute myeloid leukemia, 6; precursor B-acute lymphoblastic leukemia, 2; B-cell lymphoma, 2; and T-cell lymphoma, 1. Positive results were obtained in low-cellularity specimens, including 2 with fewer than 100 events in the population of interest. FCI was indeterminate in 19 (8.3%) of 230 specimens, including 3 with only sparse events, 8 with possible artifact (apparent lack of staining, nonspecific or background staining, and aspirated air), and 8 with phenotypic findings considered insufficient for diagnosis. Indeterminate specimens were often limited by low cellularity and lacked normal cell populations to evaluate for appropriate staining. FCI may be of value in low-cellularity CSF specimens, although the results should be interpreted with caution.

Research paper thumbnail of Cytopathologic Diagnosis of Bronchioloalveolar Carcinoma : Does It Correlate With the 1999 World Health Organization Definition?

American Journal of Clinical Pathology, 2004

We identified 29 bronchial washing, bronchoalveolar lavage, sputum, and fine-needle aspiration sp... more We identified 29 bronchial washing, bronchoalveolar lavage, sputum, and fine-needle aspiration specimens with corresponding surgical pathology specimens with features of bronchioloalveolar carcinoma (BAC). Surgical pathology correlates were reclassified according to the 1999 World Health Organization classification into pure BAC, mixed adenocarcinoma-BAC (AD-BAC), and papillary adenocarcinoma (PAP-AD). Twelve cases of invasive pulmonary adenocarcinoma (INV-AD) without a bronchioloalveolar component were reviewed for comparison. The cytology slides were evaluated for 12 features of BAC. No statistically significant feature permitted separation of BAC from AD-BAC or from PAP-AD. However, comparison of BAC with INV-AD identified 9 statistically significant cytologic features: clean background, absence of 3-dimensional clusters, neoplastic cells in flat sheets, orderly arrangement of cells with round uniform nuclei, predominance of mucinous cells, absence of nuclear overlap, absence of irregular nuclear membranes, fine granular chromatin, and nuclear grooves that were features of BAC cases. Although cytologic evaluation cannot prospectively diagnose BAC, the bronchioloalveolar pattern may be recognized and suggests in situ proliferation that is present in BAC, AD-BAC, or PAP-AD. The bronchioloalveolar pattern must be correlated with clinical, radiographic, and histologic parameters to determine whether the tumor is localized, multifocal, or diffuse and whether there is parenchymal invasion.

Research paper thumbnail of Contribution of molecular testing to thyroid fine-needle aspiration cytology of "follicular lesion of undetermined significance/atypia of undetermined significance

Cancer cytopathology, Jan 25, 2010

BACKGROUND: ''Follicular lesion of undetermined significance/atypia of undetermined significance'... more BACKGROUND: ''Follicular lesion of undetermined significance/atypia of undetermined significance'' is a heterogeneous category of cases that cannot be classified into 1 of the other established categories. The use of ancillary molecular studies has not been widely explored for this diagnosis. METHODS: All thyroid cytology cases diagnosed as follicular lesion of undetermined significance/atypia of undetermined significance were retrieved from April 2007 to December 2008. During this time period, samples were collected routinely at the time of aspiration for cytologic and molecular studies. Analysis for BRAF and RAS gene mutations and RET/PTC and PAX8/PPARc gene rearrangements were performed and correlated with the cytologic features and surgical pathology outcome. RESULTS: From a total of 513 follicular lesion of undetermined significance/atypia of undetermined significance cases identified, 455 had adequate molecular results. Of these, 117 cases had cytologic-histologic correlation. In this group, 35 (29.9%) cases had a neoplastic outcome and 20 (17.1%) cases from 19 patients were carcinoma. Positive molecular results were found in 12 cases, all of which were papillary carcinoma. There were no false-positive molecular results. In correlating the molecular results with surgical pathology outcome, we found that the cancer probability for follicular lesion of undetermined significance/atypia of undetermined significance cases with molecular alteration was 100%, while the probability for follicular lesion of undetermined significance/atypia of undetermined significance cases without molecular alteration was 7.6% (P < .001). CONCLUSIONS: By cytomorphology alone, follicular lesion of undetermined significance/atypia of undetermined significance specimens represent cases that are intermediate in risk between the benign and ''suspicious for follicular neoplasm'' categories. Although not all papillary carcinoma cases are detected by molecular testing, a positive molecular test result is very helpful in refining follicular lesion of undetermined significance/atypia of undetermined significance cases into high-risk and low-risk categories.

Research paper thumbnail of Contribution of molecular testing to thyroid fine-needle aspiration cytology of "follicular lesion of undetermined significance/atypia of undetermined significance

Cancer cytopathology, Jan 25, 2010

BACKGROUND: ''Follicular lesion of undetermined significance/atypia of undetermined significance'... more BACKGROUND: ''Follicular lesion of undetermined significance/atypia of undetermined significance'' is a heterogeneous category of cases that cannot be classified into 1 of the other established categories. The use of ancillary molecular studies has not been widely explored for this diagnosis. METHODS: All thyroid cytology cases diagnosed as follicular lesion of undetermined significance/atypia of undetermined significance were retrieved from April 2007 to December 2008. During this time period, samples were collected routinely at the time of aspiration for cytologic and molecular studies. Analysis for BRAF and RAS gene mutations and RET/PTC and PAX8/PPARc gene rearrangements were performed and correlated with the cytologic features and surgical pathology outcome. RESULTS: From a total of 513 follicular lesion of undetermined significance/atypia of undetermined significance cases identified, 455 had adequate molecular results. Of these, 117 cases had cytologic-histologic correlation. In this group, 35 (29.9%) cases had a neoplastic outcome and 20 (17.1%) cases from 19 patients were carcinoma. Positive molecular results were found in 12 cases, all of which were papillary carcinoma. There were no false-positive molecular results. In correlating the molecular results with surgical pathology outcome, we found that the cancer probability for follicular lesion of undetermined significance/atypia of undetermined significance cases with molecular alteration was 100%, while the probability for follicular lesion of undetermined significance/atypia of undetermined significance cases without molecular alteration was 7.6% (P < .001). CONCLUSIONS: By cytomorphology alone, follicular lesion of undetermined significance/atypia of undetermined significance specimens represent cases that are intermediate in risk between the benign and ''suspicious for follicular neoplasm'' categories. Although not all papillary carcinoma cases are detected by molecular testing, a positive molecular test result is very helpful in refining follicular lesion of undetermined significance/atypia of undetermined significance cases into high-risk and low-risk categories.

Research paper thumbnail of Primary pleural effusion posttransplant lymphoproliferative disorder: Distinction from secondary involvement and effusion lymphoma

Diagnostic Cytopathology, 2001

Pleural effusion presentation of posttransplant lymphoproliferative disorder (PTLD) is relatively... more Pleural effusion presentation of posttransplant lymphoproliferative disorder (PTLD) is relatively uncommon. Most examples of effusion-based PTLD have been secondary to widespread solid organ involvement, and are associated with an aggressive clinical course. We report on a case of primary effusion PTLD in a 70-yr-old male liver transplant recipient with a history of hepatitis B infection. Cytomorphologically, the pleural fluid specimen showed a monomorphous population of intermediate to large-sized transformed lymphoid cells, with irregular multilobated nuclear contours and readily identifiable mitotic figures. Flow cytometric immunophenotypic studies revealed a CD5-negative, CD10-negative, lambda immunoglobulin light chain-positive, monoclonal B-lymphocyte (CD19-positive/CD20-positive) population. The immunocytochemical stain for CD30 antigen was negative. In situ hybridization study for Epstein-Barr virus (EBV) early RNA (EBER) and Southern blot analysis for EBV terminal repeat sequences were both positive. Southern blot analysis for human herpes virus-8 (HHV-8) was negative. No solid-organ PTLD was identified, and the cytologic results supported the diagnosis of primary effusion PTLD. Immunosuppression was decreased, and 8 mo following the diagnosis of pleural fluid PTLD, the patient was stable and his pleural effusion had markedly diminished. Recognition of primary effusion PTLD and its distinction from PTLD secondarily involving the body fluids and from other lymphomas is important, since the behavior and prognosis appear different.

Research paper thumbnail of Flow Cytometric Immunophenotyping of Cerebrospinal Fluid Specimens

American Journal of Clinical Pathology, 2011

Flow cytometric immunophenotyping (FCI) is recommended in the evaluation of cerebrospinal fluid (... more Flow cytometric immunophenotyping (FCI) is recommended in the evaluation of cerebrospinal fluid (CSF) specimens for hematologic neoplasms. This study reviewed FCI of CSF specimens collected for primary diagnosis (n = 77) and follow-up for known malignancy (n = 153). FCI was positive in 11 (4.8%) of 230 specimens: acute myeloid leukemia, 6; precursor B-acute lymphoblastic leukemia, 2; B-cell lymphoma, 2; and T-cell lymphoma, 1. Positive results were obtained in low-cellularity specimens, including 2 with fewer than 100 events in the population of interest. FCI was indeterminate in 19 (8.3%) of 230 specimens, including 3 with only sparse events, 8 with possible artifact (apparent lack of staining, nonspecific or background staining, and aspirated air), and 8 with phenotypic findings considered insufficient for diagnosis. Indeterminate specimens were often limited by low cellularity and lacked normal cell populations to evaluate for appropriate staining. FCI may be of value in low-cellularity CSF specimens, although the results should be interpreted with caution.

Research paper thumbnail of Cytopathologic Diagnosis of Bronchioloalveolar Carcinoma : Does It Correlate With the 1999 World Health Organization Definition?

American Journal of Clinical Pathology, 2004

We identified 29 bronchial washing, bronchoalveolar lavage, sputum, and fine-needle aspiration sp... more We identified 29 bronchial washing, bronchoalveolar lavage, sputum, and fine-needle aspiration specimens with corresponding surgical pathology specimens with features of bronchioloalveolar carcinoma (BAC). Surgical pathology correlates were reclassified according to the 1999 World Health Organization classification into pure BAC, mixed adenocarcinoma-BAC (AD-BAC), and papillary adenocarcinoma (PAP-AD). Twelve cases of invasive pulmonary adenocarcinoma (INV-AD) without a bronchioloalveolar component were reviewed for comparison. The cytology slides were evaluated for 12 features of BAC. No statistically significant feature permitted separation of BAC from AD-BAC or from PAP-AD. However, comparison of BAC with INV-AD identified 9 statistically significant cytologic features: clean background, absence of 3-dimensional clusters, neoplastic cells in flat sheets, orderly arrangement of cells with round uniform nuclei, predominance of mucinous cells, absence of nuclear overlap, absence of irregular nuclear membranes, fine granular chromatin, and nuclear grooves that were features of BAC cases. Although cytologic evaluation cannot prospectively diagnose BAC, the bronchioloalveolar pattern may be recognized and suggests in situ proliferation that is present in BAC, AD-BAC, or PAP-AD. The bronchioloalveolar pattern must be correlated with clinical, radiographic, and histologic parameters to determine whether the tumor is localized, multifocal, or diffuse and whether there is parenchymal invasion.

Research paper thumbnail of Contribution of molecular testing to thyroid fine-needle aspiration cytology of "follicular lesion of undetermined significance/atypia of undetermined significance

Cancer cytopathology, Jan 25, 2010

BACKGROUND: ''Follicular lesion of undetermined significance/atypia of undetermined significance'... more BACKGROUND: ''Follicular lesion of undetermined significance/atypia of undetermined significance'' is a heterogeneous category of cases that cannot be classified into 1 of the other established categories. The use of ancillary molecular studies has not been widely explored for this diagnosis. METHODS: All thyroid cytology cases diagnosed as follicular lesion of undetermined significance/atypia of undetermined significance were retrieved from April 2007 to December 2008. During this time period, samples were collected routinely at the time of aspiration for cytologic and molecular studies. Analysis for BRAF and RAS gene mutations and RET/PTC and PAX8/PPARc gene rearrangements were performed and correlated with the cytologic features and surgical pathology outcome. RESULTS: From a total of 513 follicular lesion of undetermined significance/atypia of undetermined significance cases identified, 455 had adequate molecular results. Of these, 117 cases had cytologic-histologic correlation. In this group, 35 (29.9%) cases had a neoplastic outcome and 20 (17.1%) cases from 19 patients were carcinoma. Positive molecular results were found in 12 cases, all of which were papillary carcinoma. There were no false-positive molecular results. In correlating the molecular results with surgical pathology outcome, we found that the cancer probability for follicular lesion of undetermined significance/atypia of undetermined significance cases with molecular alteration was 100%, while the probability for follicular lesion of undetermined significance/atypia of undetermined significance cases without molecular alteration was 7.6% (P < .001). CONCLUSIONS: By cytomorphology alone, follicular lesion of undetermined significance/atypia of undetermined significance specimens represent cases that are intermediate in risk between the benign and ''suspicious for follicular neoplasm'' categories. Although not all papillary carcinoma cases are detected by molecular testing, a positive molecular test result is very helpful in refining follicular lesion of undetermined significance/atypia of undetermined significance cases into high-risk and low-risk categories.