Variance in 3D anatomic localization of surgical margins based on conventional margin labeling in head and neck squamous cell carcinoma.

OBJECTIVE: In head and neck cancer (HNC), positive margins are strongly predictive of treatment failure. We sought to measure the accuracy of localization of margin sampling sites based on conventional anatomic labels using a digital 3D-model. METHODS: Preoperative CT scans for 9 patients with HNC treated operatively at our institution were imported into a multiplanar radiology software, which was used to render a digital 3D model of each tumor intended to represent the resection specimen. Surgical margin labels recorded during the operative case were collected from pathology records. Margin labels (N = 64) were presented to participating physicians.Participants were asked to mark the anatomic location of each surgical margin using the 3D-model and corresponding radiographic planes for reference.For each individual margin, the 3D coordinates of each participant's marker were used to calculate a mean localization point called the geometric centroid. Mean distance from individual markers to the centroid was compared between participantsand margin types. RESULTS: Amongst 7 surgeons, markers were placed a mean distance of 12.6 mm ([SD] = 7.5) from the centroid.Deep margins were marked with a greater mean distance than mucosal/skin margins (19.6 [24.8] mm vs. 15.3 [14.9] mm, p = 0.034). When asked to relocate a margin following re-resection, surgeons marked a point an average of 20.6 [12.4] mm from their first marker with a range of 3.9- 45.1 mm. CONCLUSIONS: Retrospective localization of conventionally labeled margins is an imprecise process with variability across the care team. Future interventions targeting margin documentation and communication may improve sampling precision.

Patient with multiple genetically distinct thyroid nodules including papillary thyroid carcinoma harboring novel YWHAG-BRAF fusion.

Next-generation sequencing (NGS) analysis of thyroid samples aids in risk stratification of cytologically indeterminate nodules and contributes to our understanding of molecular mechanisms in thyroid neoplasia. Several genes, including BRAF, RAS, and EIF1AX, are known to play a role in thyroid tumorigenesis. Here we report a case of papillary thyroid carcinoma (PTC) in which a single lesion harbored a novel YWHAG-BRAF fusion and EIF1AX mutation and displayed mixed morphological findings. The patient is a 74-year-old female with multiple incidentally discovered thyroid nodules, two of which were sampled by ultrasound-guided fine needle aspiration (FNA). Cytologic diagnosis for both nodules was suspicious for follicular neoplasm (Bethesda Category IV). NGS testing of one nodule detected a novel in-frame YWHAG-BRAF fusion and a concurrent EIF1AX A113 splice mutation. The subsequent surgical resection specimen showed that this nodule exhibited two distinct morphologic patterns, conventional (classical) type and follicular variant (FV) of PTC, which were sharply demarcated and were found to harbor unique genetic alterations. Of note, this is the first report of BRAF activation through novel rearrangement with a gene encoding a 14-3-3 protein as a pathogenic factor, which underlines its significance both as a prognostic measurement and as a therapeutic target.

Characterization and Clinical Significance of EIF1AX Mutations and Co-Mutations in Cytologically Indeterminate Thyroid Nodules: A 5-Year Retrospective Analysis.

OBJECTIVE: Mutations in the EIF1AX gene have been recently detected in a small percentage of benign and malignant thyroid lesions. We sought to investigate the prevalence and clinical significance of EIF1AX mutations and co-mutations in cytologically indeterminate thyroid nodules at our institution. MATERIALS AND METHODS: A 5-year retrospective analysis was performed on thyroid nodules with a cytologic diagnosis of Bethesda category III or IV, which had undergone testing by our in-house next generation sequencing panel. Surgically resected nodules with EIF1AX mutations were identified, and mutation type and presence of co-mutations were correlated with histopathologic diagnosis. RESULTS: 41/904 (4.5%) cases overall and 26/229 (11.4%) surgically resected nodules harbored an EIF1AX mutation. The most common histologic diagnoses were follicular thyroid carcinoma and follicular variant of papillary thyroid carcinoma. 11/26 (42.3%) of nodules had isolated EIF1AX mutation. Comutations were found in RAS (12/26; 46.2%), TERT (5/26; 19.2%) and TP53 (2/26; 7.7%). EIF1AX mutation alone conferred a 36.4% risk of malignancy (ROM) and 54.5% ROM or noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP), while the ROM was significantly higher in nodules with concurrent RAS (71.4%), TERT, TP53 and RAS+TERT (100%) mutations. CONCLUSION: EIF1AX mutations occur in benign and malignant follicular thyroid neoplasms. In our cohort, the majority of mutations occurred at the splice acceptor site between exons 5 and 6. Importantly, the coexistence of EIF1AX mutations with other driver pathogenic mutations in RAS, TERT and TP53 conferred a 100% ROM or NIFTP, indicating that such nodules require surgical removal.

How Increased Nodal Metastasis and Recurrence in Cribriform Adenocarcinoma Relate to Polymorphous Adenocarcinoma and Survival: A Systematic Review.

BACKGROUND: Recently, histologic grade was removed from salivary tumor nomenclature by the WHO to include disease of higher grade. One such entity, cribriform adenocarcinoma (CAC), is an aggressive group of polymorphous adenocarcinoma (PAC), with frequent nodal metastasis and locoregional recurrence. We aim to examine the biologic behavior of this disease as compared with the PAC general cohort inclusive of all subtypes. METHODS: A systematic review of the literature on polymorphous adenocarcinoma and cribriform adenocarcinoma was completed. A descriptive analysis was performed for the following predictor variables: nodal and distant metastasis, in addition to recurrence. The outcome variables, disease free recurrence, and disease specific survival, where plotted using Kaplan-Meier curves. RESULTS: PAC and CAC both show median age of diagnosis in the sixth decade of life and a female predominance. CAC occurs most frequently in the tongue and PAC in the palate. The 2 groups show a similar biologic behavior in regards to incidence of distant metastasis (4.1 vs 5.5%), recurrence (12.5 vs 17.8%), and death from disease (3 vs 2.7%). However, there was an increased incidence of nodal metastasis in CAC (53%) as compared with that in PAC of all subtypes (14%). CONCLUSIONS: CAC exhibits more aggressive biologic behavior as compared with the PAC cohort. Although CAC is not an officially recognized entity, these tumors likely comprise a significant portion of the cases of PAC with poor outcomes and are deserving of attention and consideration for escalation in oncologic treatment.

SSTR2 Expression in Olfactory Neuroblastoma: Clinical and Therapeutic Implications.

Somatostatin receptor 2 (SSTR2) expression has previously been documented in olfactory neuroblastoma (ONB). Here, we fully characterize SSTR2 expression in ONB and correlate staining results with clinicopathologic parameters including Hyams grade. We also assess SSTR2 immunohistochemistry expression in various histologic mimics of ONB to assess its diagnostic functionality. 78 ONBs (51 primary biopsies/excisions and 27 recurrences/metastases) from 58 patients were stained for SSTR2. H-scores based on intensity (0-3 +) and percentage of tumor cells staining were assigned to all cases. 51 histologic mimics were stained and scored in an identical fashion. 77/78 (99%) ONB cases demonstrated SSTR2 staining (mean H-score: 189, range: 0-290). There were no significant differences in staining between primary tumors and recurrences/metastases (mean H-score: 185 vs 198). Primary low-grade ONB had somewhat stronger staining than high-grade tumors (mean H-score: 200 vs 174). SSTR2 expression had no prognostic value when considering disease-free or disease-specific survival. SSTR2 staining is significantly higher in ONB than its histologic mimics (mean H-score: 189 vs 12.9, p < 0.001) suggesting a potential use of the marker in diagnosis of ONB. In conclusion, SSTR2 is consistently expressed in ONB suggesting a role for somatostatin-analog based imaging and therapy in this disease. More generally, SSTR2 may be another marker of neuroendocrine differentiation in ONB.

Cytological interpretation of p16 immunohistochemistry in head and neck carcinomas: does the choice of fixative matter?

INTRODUCTION: Fine-needle aspiration (FNA) of nodal metastases plays a key role in the diagnosis of oropharyngeal squamous cell carcinoma (OPSCC). Because of significant clinical implications of human papillomavirus (HPV)-related OPSCC, immunohistochemistry for p16 as a surrogate marker for high-risk HPV is an important ancillary test. After our laboratory switched from CytoLyt to formalin fixative for FNA needle rinses generating cell block (CB) material, we investigated the impact of this protocol change on the accuracy of p16 results. MATERIALS AND METHODS: FNA specimens of head and neck lesions with p16 staining performed on CB, from 1 year before and after the implementation of formalin-fixed CB (FCB) were identified. Nuclear and cytoplasmic p16 expression was scored and compared to p16 status on corresponding surgical specimens. RESULTS: There were no false-positive results with either fixative. CytoLyt-fixed CB (CCB) had 47% (7 of 15) false-negative cases, whereas FCB had none, with 100% diagnostic accuracy for p16-negative (n = 6) and p16-positive (n = 15) results. False-negative CCB showed 0% to 10% nuclear and 0% to 65% weak cytoplasmic staining, whereas true-positive CCB showed 10% to 85% nuclear and 35% to 90% cytoplasmic staining. p16-negative FCB showed 0% nuclear and cytoplasmic staining, and p16-positive FCB showed 30% to 100% moderate-strong nuclear and cytoplasmic staining. Interobserver variability was greater with CCB. CONCLUSIONS: In our laboratory, formalin fixation of CB material improved the accuracy of p16 interpretation. Staining in FCB was also more robust than CCB, which showed weaker cytoplasmic and more focal nuclear staining. Therefore, we advocate formalin fixation for head and neck cytology specimens that may require p16 testing.

Cytohistologic correlation of basaloid salivary gland neoplasms: Can cytomorphologic classification be used to diagnose and grade these tumors?

BACKGROUND: Basaloid salivary gland neoplasms (BSNs), which include benign primary tumors and primary or metastatic malignancies, show overlapping morphology in fine-needle aspiration (FNA). The Milan system recommends assigning a grade (low or high) to malignant salivary neoplasms because of the impact on surgical planning. This study investigated cytomorphologic features of BSNs on FNA that would help to favor a high-grade malignancy over a low-grade malignancy or a benign tumor. METHODS: Two pathologists performed a double-blinded cytologic evaluation of FNA cases diagnosed as BSNs that had corresponding surgical resections. The diagnosis made with the Milan system was correlated with the final surgical diagnosis and grade. Cytologic sensitivity, specificity, and predictive values were calculated. RESULTS: There were 132 BSN FNA cases; cytology slides were available for 77 of 87 patients who had undergone resection. The risk of malignancy for the benign neoplasm (BN), salivary gland neoplasm of uncertain malignant potential (SUMP), suspicious for malignancy (SFM), and malignant categories were 13.6%, 22%, 100%, and 100%, respectively. The sensitivity of the malignant/SFM category was 51.7%; another 37.9% of confirmed malignancies were diagnosed as SUMP. The specificity of the BN category was 86%. Favoring a high-grade malignancy on FNA had 100% accuracy (5 of 5). Favoring a low-grade malignancy on FNA had 75% accuracy (6 of 8). The most specific cytomorphologic clues for a high-grade malignancy were necrotic/apoptotic debris, mitoses, discohesion, and anisonucleosis. CONCLUSIONS: BSNs encompass a broad spectrum of primary and metastatic tumors. Necrotic/apoptotic debris, mitotic activity, discohesion, and significant anisonucleosis, alone or especially in combination, should make a cytopathologist suspect a high-grade malignancy.

Novel therapeutic targets in salivary duct carcinoma uncovered by comprehensive molecular profiling.

Salivary duct carcinoma (SDC) is a rare, aggressive salivary gland malignancy, which often presents at an advanced stage. A proportion of SDC are characterized by HER2 amplification and/or overexpression of androgen receptor (AR), which could be targeted in a subset of patients, but the presence of AR splice variant-7 (AR-V7) in some SDC cases could result in resistance to anti-androgen therapy. We evaluated a cohort of 28 cases of SDC for potentially targetable biomarkers and pathways using immunohistochemistry (IHC) and next-generation sequencing (DNA and RNA) assays. Pathogenic genetic aberrations were found in all but 1 case and affected TP53 (n = 19), HRAS (n = 7), PIK3CA, ERBB2 (HER2), and NF1 (n = 5 each); KMT2C (MLL3) and PTEN (n = 3 each); BRAF (p.V600E), KDM5C and NOTCH1 (n = 2 each). Androgen receptor was expressed in all cases and 13 of 27 harbored the AR-V7 splice variant (including a case without any other detectable genetic alteration). HER2 IHC was expressed in 11 of 28 cases. The majority of SDC cases had no biomarkers predictive of immunotherapy response: 5 cases exhibited low (1%-8%) programmed death ligand 1 (PD-L1) expression in tumor cells, 2 cases exhibited elevated TMB, and no samples exhibited microsatellite instability. Notably, the pre-treatment biopsies from 2 patients with metastatic disease, who demonstrated clinical responses to anti-androgen therapy, showed AR expression and no AR splice variants. We conclude that comprehensive molecular profiling of SDCs can guide the selection of patients for targeted therapies involving AR, HER2, PD-L1, mitogen-activated protein kinase, and PIK3CA pathways.