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Assessing the Utilization of p16 Immunohistochemistry in Head and Neck Squamous Cell Carcinoma
S46
Abstracts
Materials and Methods: We performed intraoperative FNA evaluation with Diff-Quik staining in 67 uveal melanoma cases from 2009-16 in samples obtained using a transscleral/transvitreal approach. Samples were submitted for DecisionDx-UMÔ GEP tumor typing for five-year metastatic uveal melanoma risk in 42/67 cases. Diagnostic yield was supplemented with Papanicolau stained smears, ThinPrep preparations from needle rinses (nZ43) and cell blocks with immunohistochemical stains for melanocytic markers (nZ63) and Ki-67 proliferative index (nZ53). Results: The age range of cohort cases was 19-87 yrs (mean: 61.6 yrs) and male:female ratio Z 1.6:1. Tumors were located in iris, ciliary body and choroid in 1, 2 and 64 cases respectively. Diagnostic categories were ‘positive for melanoma’ (nZ64, including 7 cases with scant cellularity), ‘suspicious’ (nZ1) and ‘atypical’ (nZ2). Results of morphologic and molecular subtyping are listed in Table 1. Immunostains for 1 melanocytic marker were positive in > 90% cases. In the ‘suspicious’ case, sampled material was degenerated due to necrotic tumor. In the first ‘atypical’ case, only 1 cell with marked atypia was seen in an almost acellular specimen. In the second ‘atypical’ case, sampled material was predominantly retina with conjunctival contamination. Cell blocks were noncontributory in 10 cases. Ki-67 ranged from 1-3% in majority of cases reflecting the nature of uveal melanoma and probably limited sampling of larger tumor. Conclusion: Our study demonstrates that ROSE consistently provides adequate material for morphologic diagnosis and molecular studies in uveal melanoma.
Table 1
Uveal melanoma morphology and GEP results
PST97 The Cytologic Evaluation of Salivary Gland Neoplasms: A 5-Year Retrospective Study of Grading Concordance and Rates of Malignancy Nicholas Hunter, DO, MS, Cory Bernadt, MD, PhD. Washington University, St. Louis, MO Introduction: The cytologic stratification of salivary gland neoplasms by grade and/or morphologic class is a vital step in the early diagnostic process. Cytopathologists often rely upon broad categorical classification, with or without grade, to effectively triage specimens. The purpose of this study was to examine the grading and the classification of fine needle aspiration (FNA) specimens through the retrospective examination of rates of concordance and malignancy after excision. Materials and Methods: A 5-year institutional survey of salivary gland neoplasm FNAs was performed. Cases given a cytologic grade were compared with the grade given to the corresponding excisional pathology to assess for concordance. Separately, all FNAs classified as basaloid or oncocytic neoplasms were compared to excisional pathology to assess for rates of malignancy.
Results: A total of 40 FNAs were graded, 9 of which were lost to followup. Of the 31 remaining cases, 29 were concordant (94%) with their corresponding surgical excision. Both discordant cases were classified as low grade salivary gland neoplasm on FNA, and as high grade mucoepidermoid carcinoma on excision. Based on cytologic morphology, 29 FNAs were classified as basaloid, and 14 FNAs were classified as oncocytic. Upon excision, the rates of malignancy were 24% and 29% for basaloid and oncocytic, respectively. The malignancies of FNAs classified as basaloid included basal cell adenocarcinoma (2), adenoid cystic carcinoma (1), carcinoma-ex pleomorphic adenoma (1), basaloid squamous cell carcinoma (1), low grade malignant basal cell tumor (1) and mucoepidermoid carcinoma (1). All of the malignancies of FNAs classified as oncocytic were mucoepidermoid carcinomas. Conclusion: Although precise classification of salivary gland neoplasms by FNA is difficult, cytologic grading is highly concordant with the excised surgical specimen. In addition, morphologic classification of basaloid and oncocytic neoplasms carries a significant risk of malignancy that warrants further clinical investigation to exclude malignancy. PST98 Assessing the Utilization of p16 Immunohistochemistry in Head and Neck Squamous Cell Carcinoma Michael Sherman, MD, Cecilia Clement, MD, Vicki Schnadig, MD, Ranjana Nawgiri, MD. University of Texas Medical Branch, Galveston, TX Introduction: Immunohistochemistry (IHC) for p16 is an accepted surrogate for HPV status of squamous cell carcinomas (SqCC). The biologic distinction between HPV-driven and classical SqCC of the head and neck (H&N) has been well defined. HPV infection is related to better prognosis, increased chemo/radiosensitivity, and potential for attenuated therapy regimens. Importantly, these benefits are limited to SqCC of the oropharynx with limited studies evaluating other H&N sites. Our study evaluates the utilization of p16 in our surgical pathology (SP) and cytopathology (CP) departments with regards to tumor site and positivity rates. Materials and Methods: By computer query, a total of 73 cases of SqCC with p16 IHC were found within a 14 month period spanning 2014-2015 (40 SP and 33 CP). Sample site and p16 result with respect to a block-like 70% cutoff were recorded. Results: Of the 40 SP cases (39 primary tumors and 1 regional lymph node metastasis) 10 (25%) represented oropharyngeal primaries. Of the 33 CP cases (1 primary tumor and 32 metastases to lymph node or lung) 19 (58%) represented oropharyngeal primaries. p16 was positive in 17 of 29 (59%) oropharyngeal-derived tumors (6 SP and 11 CP) and 8 of 44 (18%) nonoropharyngeal-derived tumors (4 SP and 4 CP). Conclusions: The rate of p16 positivity in non-oropharyngeal H&N SqCC is low and current literature shows no prognostic or therapeutic impact. Conversely, oropharyngeal tumors show a high rate of p16 with therapeutic and prognostic implications. Our cohort suggests that indiscriminate utilization of p16 immunohistochemistry results in unnecessary testing in the majority of “head and neck” SqCC cases. Based on the current evidence, p16 results are only significant in oropharyngeal SqCC and non-oropharyngeal primaries may be excluded from this evaluation. PST99 Interpretation of HPV DNA In Situ Hybridization in HPV-related Head and Neck Squamous Cell Carcinoma: An Achievable Task in Cell Block and Small Biopsy Material James Miller, MD, Zahra Maleki, MD, Derek Allison, MD. Johns Hopkins Hospital, Baltimore, MD Introduction: Human papilloma virus (HPV)-related head and neck squamous cell carcinoma (HNSCC) is a distinct entity with a better
Abstracts
Materials and Methods: We performed intraoperative FNA evaluation with Diff-Quik staining in 67 uveal melanoma cases from 2009-16 in samples obtained using a transscleral/transvitreal approach. Samples were submitted for DecisionDx-UMÔ GEP tumor typing for five-year metastatic uveal melanoma risk in 42/67 cases. Diagnostic yield was supplemented with Papanicolau stained smears, ThinPrep preparations from needle rinses (nZ43) and cell blocks with immunohistochemical stains for melanocytic markers (nZ63) and Ki-67 proliferative index (nZ53). Results: The age range of cohort cases was 19-87 yrs (mean: 61.6 yrs) and male:female ratio Z 1.6:1. Tumors were located in iris, ciliary body and choroid in 1, 2 and 64 cases respectively. Diagnostic categories were ‘positive for melanoma’ (nZ64, including 7 cases with scant cellularity), ‘suspicious’ (nZ1) and ‘atypical’ (nZ2). Results of morphologic and molecular subtyping are listed in Table 1. Immunostains for 1 melanocytic marker were positive in > 90% cases. In the ‘suspicious’ case, sampled material was degenerated due to necrotic tumor. In the first ‘atypical’ case, only 1 cell with marked atypia was seen in an almost acellular specimen. In the second ‘atypical’ case, sampled material was predominantly retina with conjunctival contamination. Cell blocks were noncontributory in 10 cases. Ki-67 ranged from 1-3% in majority of cases reflecting the nature of uveal melanoma and probably limited sampling of larger tumor. Conclusion: Our study demonstrates that ROSE consistently provides adequate material for morphologic diagnosis and molecular studies in uveal melanoma.
Table 1
Uveal melanoma morphology and GEP results
PST97 The Cytologic Evaluation of Salivary Gland Neoplasms: A 5-Year Retrospective Study of Grading Concordance and Rates of Malignancy Nicholas Hunter, DO, MS, Cory Bernadt, MD, PhD. Washington University, St. Louis, MO Introduction: The cytologic stratification of salivary gland neoplasms by grade and/or morphologic class is a vital step in the early diagnostic process. Cytopathologists often rely upon broad categorical classification, with or without grade, to effectively triage specimens. The purpose of this study was to examine the grading and the classification of fine needle aspiration (FNA) specimens through the retrospective examination of rates of concordance and malignancy after excision. Materials and Methods: A 5-year institutional survey of salivary gland neoplasm FNAs was performed. Cases given a cytologic grade were compared with the grade given to the corresponding excisional pathology to assess for concordance. Separately, all FNAs classified as basaloid or oncocytic neoplasms were compared to excisional pathology to assess for rates of malignancy.
Results: A total of 40 FNAs were graded, 9 of which were lost to followup. Of the 31 remaining cases, 29 were concordant (94%) with their corresponding surgical excision. Both discordant cases were classified as low grade salivary gland neoplasm on FNA, and as high grade mucoepidermoid carcinoma on excision. Based on cytologic morphology, 29 FNAs were classified as basaloid, and 14 FNAs were classified as oncocytic. Upon excision, the rates of malignancy were 24% and 29% for basaloid and oncocytic, respectively. The malignancies of FNAs classified as basaloid included basal cell adenocarcinoma (2), adenoid cystic carcinoma (1), carcinoma-ex pleomorphic adenoma (1), basaloid squamous cell carcinoma (1), low grade malignant basal cell tumor (1) and mucoepidermoid carcinoma (1). All of the malignancies of FNAs classified as oncocytic were mucoepidermoid carcinomas. Conclusion: Although precise classification of salivary gland neoplasms by FNA is difficult, cytologic grading is highly concordant with the excised surgical specimen. In addition, morphologic classification of basaloid and oncocytic neoplasms carries a significant risk of malignancy that warrants further clinical investigation to exclude malignancy. PST98 Assessing the Utilization of p16 Immunohistochemistry in Head and Neck Squamous Cell Carcinoma Michael Sherman, MD, Cecilia Clement, MD, Vicki Schnadig, MD, Ranjana Nawgiri, MD. University of Texas Medical Branch, Galveston, TX Introduction: Immunohistochemistry (IHC) for p16 is an accepted surrogate for HPV status of squamous cell carcinomas (SqCC). The biologic distinction between HPV-driven and classical SqCC of the head and neck (H&N) has been well defined. HPV infection is related to better prognosis, increased chemo/radiosensitivity, and potential for attenuated therapy regimens. Importantly, these benefits are limited to SqCC of the oropharynx with limited studies evaluating other H&N sites. Our study evaluates the utilization of p16 in our surgical pathology (SP) and cytopathology (CP) departments with regards to tumor site and positivity rates. Materials and Methods: By computer query, a total of 73 cases of SqCC with p16 IHC were found within a 14 month period spanning 2014-2015 (40 SP and 33 CP). Sample site and p16 result with respect to a block-like 70% cutoff were recorded. Results: Of the 40 SP cases (39 primary tumors and 1 regional lymph node metastasis) 10 (25%) represented oropharyngeal primaries. Of the 33 CP cases (1 primary tumor and 32 metastases to lymph node or lung) 19 (58%) represented oropharyngeal primaries. p16 was positive in 17 of 29 (59%) oropharyngeal-derived tumors (6 SP and 11 CP) and 8 of 44 (18%) nonoropharyngeal-derived tumors (4 SP and 4 CP). Conclusions: The rate of p16 positivity in non-oropharyngeal H&N SqCC is low and current literature shows no prognostic or therapeutic impact. Conversely, oropharyngeal tumors show a high rate of p16 with therapeutic and prognostic implications. Our cohort suggests that indiscriminate utilization of p16 immunohistochemistry results in unnecessary testing in the majority of “head and neck” SqCC cases. Based on the current evidence, p16 results are only significant in oropharyngeal SqCC and non-oropharyngeal primaries may be excluded from this evaluation. PST99 Interpretation of HPV DNA In Situ Hybridization in HPV-related Head and Neck Squamous Cell Carcinoma: An Achievable Task in Cell Block and Small Biopsy Material James Miller, MD, Zahra Maleki, MD, Derek Allison, MD. Johns Hopkins Hospital, Baltimore, MD Introduction: Human papilloma virus (HPV)-related head and neck squamous cell carcinoma (HNSCC) is a distinct entity with a better