Utility of parathyroid hormone immunocytochemistry in fine needle aspiration diagnosis of parathyroid tissue.

OBJECTIVE: The cytomorphological features of parathyroid tissue (PTT) may overlap with those of thyroid lesions, thus posing a diagnostic challenge. In this retrospective study, we reviewed our institutional experience in using parathyroid hormone (PTH) immunocytochemistry (ICC) to substantiate the diagnosis of PTT on fine needle aspiration (FNA). METHODS: Our pathology database was searched for FNA cases in which PTH ICC was performed between 1 January 2015 and 31 March 2022. PTH ICC was performed on a ThinPrep slide in cases with a clinical suspicion of PTT or with cytomorphological features raising the possibility of PTT. Patients' clinicopathological characteristics, PTH ICC results, cytological diagnoses, and surgical follow-ups, if available, were reviewed and analysed. RESULTS: The study cohort included 103 cases clinically designated as thyroid (n = 85, 82.5%), parathyroid (n = 11, 10.7%) and neck soft tissue (n = 7, 6.8%). PTH immunostaining was negative, positive, and indeterminate in 53 (51.5%), 27 (26.2%), and 23 (22.3%) cases, respectively. Surgical follow-up was available in 27 (26.2%) cases, including 17 thyroid lesions and 10 PTT cases. All positive PTH cases were confirmed to be PTT, while all but one of the negative PTH cases were non-PTT on follow-up. The calculated sensitivity, specificity, positive and negative predictive values were 85.7%, 100%, 100% and 93.3%, respectively. CONCLUSION: Our study demonstrates that PTH ICC performed on additional ThinPrep slides is a valuable adjunct test in FNA samples with a differential diagnosis of PTT vs non-PTT. Low cellularity may be a limiting factor in the accurate assessment of PTH by ICC.

TP53 Mutation-driven Stratified Mucin-producing Carcinoma Coexisting With Squamous Cell Carcinoma of the Vulva: A Case Study.

Associated with high-risk human papillomavirus infection, invasive stratified mucin-producing carcinoma is a recently characterized adenocarcinoma of the cervix. It often occurs in association with adjacent stratified mucin-producing intraepithelial lesion. Differentiated vulvar intraepithelial neoplasia and related invasive squamous cell carcinoma often arise in background vulvar lichen sclerosus with TP53 mutation as the underlying molecular signature. We present a unique case of vulvar invasive stratified mucin-producing carcinoma-like component coexisting with invasive squamous cell carcinoma in a 64-year-old woman. Both neoplastic components were proven TP53 -driven processes arising in the background of differentiated vulvar intraepithelial neoplasia and lichen sclerosus. The invasive stratified mucin-producing carcinoma-like component behaved aggressively in this case, evidenced by the presence of lymphovascular invasion and inguinal lymph node metastasis.

Breast implant-associated anaplastic large-cell lymphoma: A series of two case reports diagnosed by cytopathology.

Breast implant-associated anaplastic large-cell lymphoma (BIA-ALCL) is a rare T-cell lymphoma with a good prognosis. It occurs in association with textured breast implants. Its most common presentation is a late-onset peri-implant effusion. We present two cases of BIA-ALCL diagnosed by cytopathological examination of the fluid collection and describe the cytopathologic findings. Both patients were disease free after implant removal. This report highlights the contribution of the cytopathologic analysis to early diagnosis and definite treatment of BIA-ALCL.

Ki-67 index assessment on FNA specimens of gastrointestinal stromal tumor: Correlation with mitotic rate and potential predictive value for risk stratification.

BACKGROUND: Risk assessment of gastrointestinal stromal tumor (GIST) is challenging on cytology specimens. This study aims to determine whether Ki-67 index evaluated on fine-needle aspiration (FNA) specimens can correlate with the mitotic rate of GIST in surgical specimens and provide further risk assessment. METHODS: Cases with cell blocks containing adequate tumor cells and surgical resections were included. Ki-67 immunostain was retrospectively performed on cell block sections, and Ki-67 index was calculated on the "hot spot" areas. RESULTS: This study included 50 GIST cases from stomach (n = 45; 90%), duodenum (n = 4; 8%), and distal esophagus (n = 1; 2%). The tumor size ranged from 1.5 cm to 21 cm (mean, 5.4 cm). Based on the mitotic count, 37 GISTs (74%) had low mitotic rate (LMR) and 13 GISTs (26%) had high mitotic rate (HMR). The spindle cell, epithelioid, and mixed types accounted for 60%, 14%, and 26% of GIST, respectively. Ki-67 index counted on cell block sections correlated well with mitotic count evaluated in surgical specimens (r = 0.8031). Mean Ki-67 index was higher in HMR than LMR groups (3.5% vs. 1%, p < .001). The receiver operating characteristic curve using Ki-67 index to predict mitotic rate was further analyzed, and area under the curve was 0.839. Using a cutoff of 2.5% yielded a sensitivity of 70% at 92% specificity. CONCLUSIONS: This study demonstrates good correlations between Ki-67 index and mitotic count or risk stratification, suggesting that Ki-67 index evaluated on cytology specimens may offer a promising approach to preoperatively predict the mitotic rate and risk of GIST.

Copy number variations identified in thyroid FNA specimens are associated with Hürthle cell cytomorphology.

BACKGROUND: The fine-needle aspiration (FNA) diagnosis of thyroid Hürthle cell neoplasms (HCNs) remains challenging. This study explored a possible association of copy number variations (CNVs) with Hürthle cell lesions of the thyroid. METHODS: Thyroid FNA cases that were diagnosed as follicular lesion of undetermined significance (FLUS) or follicular neoplasm (FN)/HCN for which the ThyroSeq version 3 genomic classifier test was performed were retrieved. RESULTS: A total of 324 thyroid FNA cases (228 FLUS cases, 46 HCN cases, and 50 FN cases) were included in the study. FLUS cases were further classified as Hürthle cell type (follicular lesion of undetermined significance-Hürthle cell type [FLUS-HCT]; 20 cases) or non-Hürthle cell type (follicular lesion of undetermined significance-non-Hürthle cell type [FLUS-NHCT]; 208 cases). HCN and FLUS-HCT cases showed a higher prevalence of CNVs (23 of 66 [35%]) in comparison with those classified as FN or FLUS-NHCT (14 of 258 [5%]; P < .001). A total of 105 patients had histopathologic follow-up. Cases with CNVs were more likely to be neoplastic (18 of 26 [69%]) and associated with Hürthle cell changes (14 of 26 [54%]) in comparison with cases without any molecular alterations (neoplastic, 8 of 24 [33%]; Hürthle cell changes, 2 of 24 [8%]; P < .05). In HCN/FLUS-HCT cases with CNVs (n = 14), Hürthle cell changes (13 of 14 [93%]) and neoplasms (9 of 14 [64%]) were more likely to be seen on surgical follow-up in comparison with the 17 cases without CNVs (Hürthle cell changes, 6 of 17 [35%]; neoplastic, 3 of 17 [18%]; P < .05). CONCLUSIONS: CNVs identified in thyroid FNA cases are associated with Hürthle cell morphology and are suggestive of a neoplasm with Hürthle cell features in thyroid FNAs classified as FLUS-HCT/HCN. This finding may be helpful in triaging patients who would benefit from surgical management.

RAS mutation and associated risk of malignancy in the thyroid gland: An FNA study with cytology-histology correlation.

BACKGROUND: Activating point mutations of the RAS gene (NRAS, HRAS, and KRAS) can be seen in benign and malignant thyroid tumors; among these, NRAS mutations are more commonly seen. This study was conducted to evaluate the thyroid risk of malignancy (ROM) associated with RAS mutations in thyroid fine-needle aspiration (FNA) at the authors' institution. METHODS: The authors searched their electronic database system between January 2015 and May 2021 for thyroid FNA cases with any type of RAS mutation. Molecular alterations were identified with the ThyroSeq Genomic Classifier, ThyGeNEXT (thyroid oncogene panel)/ThyraMIR (miRNA classifier), or ThyroSure gene panel. RESULTS: A total of 127 cases (age, 51 ± 14 years; 100 females and 27 males) were identified, and 72 had histologic follow-up. The overall ROM associated with RAS mutations (with or without any other molecular alterations) was 29%, whereas the ROM was lower (18%) with RAS mutations only. Isolated NRAS, HRAS, and KRAS mutation-associated ROMs were 15%, 27%, and 14%, respectively. Among these RAS-mutated cases, the cases with a Bethesda category IV cytologic diagnosis had a higher ROM than the cases with a category III diagnosis (38% vs 17%). Twenty-one histologically confirmed malignant cases were mostly classified on cytology as category IV lesions (14 of 34; 41%), and the remainder were either category III (6 of 35; 17%) or V lesions (1 of 1; 100%). CONCLUSIONS: This study demonstrated that the overall RAS mutation-associated ROM in thyroid FNA was intermediate (29%), and isolated HRAS mutations appeared to have a higher ROM (27%) than NRAS and KRAS mutations (15% and 14%, respectively).

Performing Calcitonin Immunocytochemistry on an Additional ThinPrep Slide in Fine-Needle Aspiration Diagnosis of Medullary Thyroid Carcinoma.

OBJECTIVES: This study reviewed the institutional experience of performing calcitonin immunostain on an additional ThinPrep slide in fine-needle aspiration (FNA) diagnosis of medullary thyroid carcinoma (MTC). METHODS: Thyroid FNA cases with MTC suspected or included in the differential diagnosis during cytologic evaluation and calcitonin immunostain performed were retrieved and reviewed. RESULTS: Calcitonin immunostain was performed in 132 cases with 41 positive, 81 negative, and 10 indeterminate results. All calcitonin-positive cases had a cytologic diagnosis of MTC while all calcitonin-negative cases were cytologically classified as non-MTCs except for two cases suspicious for MTC. In 10 cases with an indeterminate calcitonin result, diagnoses of non-MTC and suspicious for MTC were rendered in 6 and 4 cases, respectively. Histopathologic follow-up was available in 85 (64%) cases. All cytologically diagnosed MTC cases were confirmed on histopathology. In 3 MTC cases with an indeterminate calcitonin result, 1 case was misclassified cytologically as follicular neoplasm. The calculated sensitivity, specificity, positive predictive value, and negative predictive value of calcitonin immunostain were all 100% for diagnosing MTC. CONCLUSIONS: Our study demonstrates the feasibility of performing calcitonin immunostain on an additional ThinPrep slide. Calcitonin immunocytochemistry is a valuable adjunct test for FNA diagnosis and differential diagnosis of MTC.

Anaplastic Thyroid Carcinoma: Cytomorphologic Features on Fine-Needle Aspiration and Associated Diagnostic Challenges.

OBJECTIVES: Anaplastic thyroid carcinoma (ATC) is an aggressive malignancy, and early diagnosis, often aided by fine-needle aspiration (FNA), is key to improving patient prognosis. While the current literature describes some of the cytologic features (CFs) of this entity, a comprehensive examination of the CFs has not yet been performed. METHODS: We retrospectively searched our electronic database for ATC cases with available slides between January 2008 and December 2019. Cases were examined for 22 CFs and compared with a control group of differentiated thyroid carcinoma. RESULTS: A total of 18 ATC cases meeting our inclusion criteria were identified. Most cases showed moderate to high cellularity (83%) and epithelioid cytomorphology (83%). Architecture included either predominantly groups/clusters of tumor cells (56%) or single tumor cells (44%). The other CFs were as follows: nuclear enlargement (100%), nuclear crowding (89%), nuclear membrane irregularities (100%), multinucleated tumor cells (33%), and background acute inflammatory cells (50%). Of the CFs examined, statistically significant differences between ATC and the control groups were found in the following: nuclear pleomorphism, coarse/clumped chromatin, macronucleoli, apoptosis, and necrosis. CONCLUSIONS: Identification of key CFs in FNA coupled with the clinical history aids in the diagnosis of ATC and helps distinguish it from other mimickers.

Increased Detection of Mycobacterium tuberculosis Disease Using a Tissue-Based Laboratory-Developed Polymerase Chain Reaction Assay Compared to Standard Diagnostics.

Standard diagnostics for Mycobacterium tuberculosis (MTB) including acid-fast bacilli (AFB) smear and culture, and Xpert™ MTB/RIF real-time Polymerase Chain Reaction (RT-PCR; Xpert) have variable sensitivity and/or long turnaround times. We describe the clinical performance of a laboratory-developed tissue-based MTB PCR compared with AFB culture and Xpert using a composite reference standard (CRS). Over an 8-year period, MTB PCR was performed on pulmonary, pleural, or lymph node specimens for 36 patients. Of these, 11 met criteria for confirmed/probable MTB using CRS. MTB PCR was positive in 100% (11/11), AFB cultures were positive in 73% (8/11), and Xpert in 0% (0/4). MTB PCR was negative in 25 cases of "No MTB" (100% specific). The MTB PCR assay resulted faster than positive AFB culture (mean time 4.3 versus 21.2 days). Tissue-based MTB PCR was associated with increased and rapid detection of MTB, improving clinical sensitivity in strongly suspected MTB cases.

Expression of insulinoma-associated protein 1 in non-small cell lung cancers: a diagnostic pitfall for neuroendocrine tumors.

Insulinoma-associated protein 1 (INSM1) has been reported as a highly sensitive and specific marker of neuroendocrine tumors. INSM1 expression has also been reported, although uncommonly, in non-neuroendocrine tumors. This study aimed to elucidate potential nonspecific INSM1 expression in non-small cell non-neuroendocrine lung cancers (NSCNELCs), especially in squamous cell carcinomas (SqCCs) with basaloid features to avoid diagnostic pitfalls. Tissue microarrays (TMAs) were constructed for 324 NSCNELCs, including 196 adenocarcinomas (AdCs), 86 SqCCs, and 42 other NSCNELCs. In addition, 38 whole-tissue sections of SqCCs with basaloid features were examined. INSM1 immunostain was semiquantitively evaluated based on the percentage of nuclear staining in tumor cells, categorized as negative, focal (<10% tumor cells), and positive (>10% tumor cells). Among 324 TMAs, 6.2% (20/324) were positive for INSM1, 4.9% (16/324) were focal, and 88.9% (289/34) were negative. Of 196 AdCs, 5.1% (10/196) were positive for INSM1, 4.7% (9/196) were focal, and 90.3% (177/196) were negative. Of 86 SqCCs, 9.3% (8/86) were positive for INSM1, 5.8% (5/86) were focal, and 84.9% (73/86) were negative. Of the remaining 42 NSCNELCs, 4.8% (2/42) were positive for INSM1, 4.8% (2/42) were focal, and 90.4% (38/44) were negative. Among 38 cases of whole-tissue sections of SqCCs with basaloid features, 15.8% (6/38) were positive for INSM1, 18.4% (7/38) were focal, and 65.8% (25/38) were negative. Our study demonstrates that INSM1 is expressed in a significant subset of NSCNELCs, suggesting caution in interpreting INSM1 staining, especially with limited samples. INSM1 should not be used as a stand-alone neuroendocrine marker in differentiating primary lung tumors.

High-Risk Human Papillomavirus Testing, Genotyping, and Histopathologic Follow-up in Women With Abnormal Glandular Cells on Papanicolaou Tests.

OBJECTIVES: This study examined the association of high-risk human papillomavirus (hrHPV) status and HPV genotype with histopathologic follow-ups in women with an atypical glandular cell (AGC) interpretation. METHODS: Cases with AGC interpretation on a Papanicolaou (Pap) test were retrieved along with hrHPV testing, genotyping, and histologic follow-up results if available. RESULTS: A total of 561 AGC cases were identified, with histologic follow-up available for 471 cases (84%). The follow-up diagnoses included benign or reactive changes (60% of cases), low-grade cervical intraepithelial neoplasia (18%), high-grade cervical intraepithelial neoplasia (CIN2-3; 7%), cervical carcinoma (5%), and other malignancies (10%). Tests for hrHPV were positive in 128 of 426 (30%) cases, including HPV16 (30%), HPV18 (14%) and other HPV subtypes (56%). A positive hrHPV result significantly increased the risk of developing CIN2-3 or cervical carcinoma (odds ratio, 24.6; 95% CI, 9.9-58.9) and HPV16 or HPV18 further increased the risk (odds ratio, 49.5; 95% CI, 17.7-123.7). CONCLUSIONS: Our data demonstrate that in women with an AGC Pap interpretation, a positive hrHPV result, especially type 16 or 18, is associated with an increased risk of developing cervical CIN2-3 or higher lesions, suggesting potential implications of hrHPV testing for the management of patients with an AGC result on a Pap test.

Prognostic Assessment of BRAF Mutation in Preoperative Thyroid Fine-Needle Aspiration Specimens.

OBJECTIVES: We investigate the potential role of BRAF testing in guiding surgical intervention in papillary thyroid carcinoma (PTC). METHODS: Thyroid fine-needle aspiration (FNA) cases with available BRAF result and follow-up thyroidectomy for PTC were included in the study. Cytology and surgical diagnoses were correlated with BRAF status. RESULTS: There were 151 cases of thyroid FNA specimens with BRAF testing (70 mutant and 81 wild-type BRAF) and histologically confirmed unilateral, unifocal PTCs. There were no differences in age, sex, tumor size, or lymphovascular invasion on thyroidectomy specimens between mutant and wild-type BRAF cases. BRAF mutation was significantly associated with cytology diagnosis (P < .001), PTC subtype (P < .001), extrathyroidal extension (ETE) (P = .006), and higher tumor (T) stage (P = .04). However, an analysis within the histologic subtypes of PTC revealed no significant association between BRAF mutation and ETE or higher T stage. There was also no difference in central (P = .847) or lateral (p = 1) neck lymph node (LN) metastasis. CONCLUSIONS: BRAF mutation identified in thyroid FNA specimens correlates with histologic subtypes but is not an independent factor for predicting PTC biological behavior and should not be used to guide the extent of LN dissection.

Quantitative assessment of p16 expression in FNA specimens from head and neck squamous cell carcinoma and correlation with HPV status.

BACKGROUND: This study investigated p16 by immunohistochemistry (IHC) on cellblocks (CBs) and human papillomavirus (HPV) by polymerase chain reaction (PCR) in fine-needle aspiration (FNA) of head and neck squamous cell carcinoma (HNSCC). METHODS: Receiver operating characteristic (ROC) curve analysis was used to assess test performance in CBs compared with p16 IHC in 42 surgical specimens from patients with HNSCC and in correlation with HPV by PCR in cytology specimens. The study assessed HPV by PCR in FNA specimens as a substitute for p16 IHC in surgical specimens. RESULTS: Of 42 cases, 38 CBs showed malignant cells as cohesive clusters of viable cells with or without single tumor cells, whereas 4 specimens were composed exclusively of single tumor cells and degenerated cells. All p16-negative surgical specimens showed an absence of p16 staining in the corresponding CBs (n = 16). In the p16-positive surgical cases (n = 26), corresponding CBs with tumor clusters (n = 23) showed heterogeneous p16 expression ranging from 40% to 100%; however, scoring single cells was challenging and unreliable because of cellular degradation. ROC curve inspection showed the optimal threshold to be at least 40% p16 staining in tumor clusters with 100% sensitivity and specificity. In cases with inadequate CBs, HPV by PCR on needle rinse showed 88% sensitivity and 100% specificity for p16 expression in surgical specimens. CONCLUSIONS: A cutoff of at least 40% p16 expression in tumor clusters may be appropriate for p16 positivity in cytology CB specimens. A positive HPV finding by PCR on needle rinse can be used as a substitute for p16 expression in surgical specimens.

Expression of NKX3.1, Prostatic Specific Antigen and Prostatic Specific Alkaline Phosphatase in Cytology Specimens of Metastatic Prostatic Carcinoma.

Background and objectives: NKX3.1 is an emerging marker for tumors of prostatic origin; however, the utility and diagnostic values of NKX3.1 have not been broadly studied in cytology specimens. The purpose of this study is to determine the performance of NKX3.1, compared to prostatic specific antigen (PSA) and prostatic specific alkaline phosphatase (PSAP), as an organ-specific marker of metastatic prostatic adenocarcinoma (MPAC) in cytology specimens. Methods: The cytology specimens, which had been evaluated to include or exclude MPAC, were collected from our pathology database. Immunostains for PSA, PSAP, and NKX3.1 were performed on cell block sections. Results: A total of 118 cases were collected. In 37 MPACs, NKX3.1 was diffusely positive in 34 cases (92%) and focally positive in 3 cases (8%). PSA indicated diffuse positivity in 16 cases (43%), focal positivity in 13 (35%) cases, and was negative in 8 (22%) cases. PSAP immunostain was performed in only 12 MPACs, showing diffuse positivity in 5 (42%), focal positivity in 3 (25%), and negativity in 4 (33%) cases. Among the 81 non-metastatic prostatic adenocarcinoma cases, NKX3.1 was negative in 80 (99%) cases and focally positive in only 1 (1%) case; all cases with available PSA and PSAP staining were negative. The calculated sensitivities for NKX3.1, PSA, and PSAP were 100%, 78%, and 67%, respectively, while the specificities were 99%, 100%, and 100%, respectively. Conclusions: Compared to PSA and PSAP, NKX3.1 is more reliable as an individual marker for MPAC in cytology specimens. Combining NKX3.1 and PSA can be useful in some cases to enhance diagnostic utility.

Fine-needle aspiration cytomorphology of papillary thyroid carcinoma with NTRK gene rearrangement from a case series with predominantly indeterminate cytology.

BACKGROUND: Neurotrophic tyrosine kinase receptor (NTRK) rearrangement has been reported in a subset of papillary thyroid carcinoma (PTC) cases. Little is known about the cytomorphologic features of NTRK-rearranged PTC. METHODS: We report an institutional series of 13 fine-needle aspiration (FNA) specimens of NTRK-rearranged PTC with a predominantly indeterminate cytology diagnosis. NTRK3 or NTRK1 rearrangements were detected on FNA or surgical specimens by next-generation sequencing. RESULTS: The 13 patients had a median age of 18 years; 10 patients were female and 3 patients were male. In 10 (77%) cases, cytology was indeterminate, and histopathologic follow-up was predominantly the follicular variant of PTC (n = 8 [62%]), mostly infiltrative subtype. Of 12 FNA specimens available for review, a predominant loosely cohesive group pattern was the most commonly encountered architectural pattern (n = 5 [41%]), followed by single cell (n = 3 [25%]), thick cord (n = 2 [17%]), and microfollicular pattern (n = 2 [17%]). Background lymphocytic thyroiditis was observed in 9 cases. At the cellular level, the cytoplasm was moderate and granular, occasionally vacuolated. Classic PTC nuclear features (eg, nuclear enlargement, elongation, grooves, and nuclear membrane irregularity) were present but were often focal and subtle. Chromatin was often granular. Intranuclear pseudoinclusions were absent or rare. CONCLUSION: Our study demonstrates that most cases of NTRK rearrangement lack classic PTC cytomorphologic characteristics. Loosely cohesive groups and single cells with granular, sometimes vacuolated cytoplasm and subtle nuclear features are often seen on FNA specimens. Recognizing these characteristics may be helpful to preoperatively prompt molecular testing, including NTRK rearrangement analysis.

Gomori Methenamine Silver Stain on Bronchoalveolar Lavage Fluid Is Poorly Sensitive for Diagnosis of Pneumocystis jiroveci Pneumonia in HIV-Negative Immunocompromised Patients and May Lead to Missed or Delayed Diagnoses.

CONTEXT.­: Direct visualization of Pneumocystis jiroveci organisms, using Gomori methenamine silver (GMS) staining in bronchoalveolar lavage fluid (BAL), is a historical gold standard that has been widely used for the diagnosis of P jiroveci pneumonia (PJP). However, the stain may be less sensitive in human immunodeficiency virus (HIV)-negative immunocompromised patients owing to a lower burden of organisms. OBJECTIVES.­: To assess the sensitivity of the GMS stain on BAL fluid for the diagnosis of PJP in HIV-negative immunocompromised patients as compared to HIV-positive patients. DESIGN.­: We conducted a retrospective review from 2012 to 2018 to identify immunocompromised patients (≥18 years old) who underwent bronchoscopy with BAL GMS staining for the diagnosis of PJP. To assess for sensitivity, we sought to identify BAL GMS-positive cases and BAL GMS-negative cases of PJP. The BAL GMS-negative cases were categorized into proven and probable PJP. RESULTS.­: We identified 45 adult immunocompromised patients with proven and probable PJP, including 24 HIV-negative (11 BAL GMS-positive and 13 BAL GMS-negative) and 21 HIV-positive cases (all were BAL GMS-positive). The sensitivity of BAL GMS for the diagnosis of PJP in HIV-negative immunocompromised patients was 11 of 24 (46%) versus 21 of 21 (100%) in HIV-positive patients (CD4: median, 10 cells/mL; range, 3-300 cells/mL). Delayed or missed diagnoses were seen in 3 cases of BAL GMS-negative PJP. Re-examination of BAL GMS slides showed rare P jiroveci cysts in 1 case. CONCLUSIONS.­: BAL GMS has poor sensitivity for PJP in HIV-negative immunocompromised patients. Using BAL GMS as a sole method for PJP may result in missed or delayed diagnoses in this population.

Grading Pancreatic Neuroendocrine Tumors by Ki-67 Index Evaluated on Fine-Needle Aspiration Cell Block Material.

OBJECTIVES: This study aimed to determine whether Ki-67 index evaluated on cytologic material could reliably grade pancreatic neuroendocrine tumors (PanNETs). METHODS: Cases with adequate cell block and available surgical specimens were included. Ki-67 index was calculated using "eyeballing," "hot spot," and "complete" counting methods. RESULTS: The overall concordance rates between cytology and surgical specimens were 71%, 73%, and 59%, respectively, by using eyeballing, hot spot, and complete counting approaches. All grade 1 tumors were correctly graded on cytology, but in grade 2 tumors concordance rates were only 36%, 41%, and 9%, respectively. All grade 2 tumors were undergraded when cell blocks contained fewer than 1,000 cells, while concordance rate increased to 57%, 64%, and 14%, respectively, in cases with 1,000 cells or more. CONCLUSIONS: Grade 2 PanNETs can be significantly undergraded when Ki-67 index is evaluated on cell block material. In cases with 1,000 or more cells, the hot spot counting method has better correlation with surgical specimens.

The Value of Negative Diagnosis in Thyroid Fine-Needle Aspiration: a Retrospective Study with Histologic Follow-Up.

The Bethesda System for reporting thyroid cytopathology (BSRTC) predicts an incidence of malignancy of less than 5% in thyroid nodules with a benign diagnosis on fine-needle aspiration (FNA). However, recent series have suggested that the true rate of malignancy might be significantly higher in this category of patients. We reviewed our experience by performing a retrospective analysis of patients with benign thyroid FNA results who underwent thyroidectomy between 2008 and 2013 at a large academic center. Information including demographics, ultrasound features, FNA diagnosis, and surgical follow-up information were recorded. Slides were reviewed on cytology-histology discrepant cases, and it was determined whether the discrepancy was due to sampling or interpretation error. A total of 802 FNA cases with a benign diagnosis and surgical follow-up were identified. FNA diagnoses included 738 cases of benign goiter and 64 cases of lymphocytic thyroiditis. On subsequent surgical resection, 144 cases were found to be neoplastic, including 117 malignant cases. False negative, defined as interpretation error and inadequate biopsy of the nodule harboring malignancy, was 6%. When cases of noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) were excluded from the analysis, false-negative rate was 5%. When microPTC cases were excluded, false-negative rate was 3% and was slightly less than 3% when both microPTC and NIFTP cases were excluded from the analysis. Retrospective review of neoplastic cases showed that 57% were due to sampling error and 43% were due to interpretation error. Interpretation error was more likely to occur in follicular patterned neoplasms (75%), while sampling error was more common in non-follicular variants of papillary thyroid carcinoma (non-FVPTC) (61%). With the exclusion of microPTC, interpretation errors were still more likely to occur in follicular neoplasms (79%) but there was no significant difference in sampling error between non-FVPTC (37%) and follicular patterned neoplasms (42%). Tumor size was larger in cases with interpretation error (mean = 2.3 cm) compared to cases with sampling error (mean = 1.4 cm). This study shows that the false-negative rate of thyroid FNA at our institution is not significantly above the rate suggested by the BSRTC. Interpretation errors were more likely to occur in follicular patterned neoplasms, while non-FVPTC was more frequently found in false negative cases due to inadequate sampling.

Long-term outcomes among breast cancer patients with extensive regional lymph node involvement: implications for locoregional management.

Extensive lymph node (LN) involvement portends significant risk for distant metastasis (DM) among breast cancer patients. As a result, local management may be of secondary import to systemic control in this population. We analyzed patients with ≥10 involved LNs (N3) to evaluate the feasibility of breast conserving therapy (BCT) vs modified radical mastectomy (MRM) in this high-risk cohort. Among 98 women with N3 disease 46 (46.9%) underwent BCT and 52 (53.1%) received MRM. Nearly all patients (92%) received comprehensive radiotherapy (RT) including axillary and supraclavicular fields. The Kaplan-Meier method and Cox regression analyses were used to analyze time-to-event outcomes. Median follow-up was 76 months, with a 5-year DFS of 64.9% and OS of 71.9% among the cohort. Poorly differentiated (p = 0.007), ER-negative tumors (p = 0.015) had adverse DFS outcomes. Treatment groups did not differ with regard to 10-year DFS (45.4% for MRM vs. 57.6% for BCT; p = 0.31), or OS (61.4 vs. 63.7%; p = 0.79). DM-free survival was 48.9% following MRM and 60.6% following BCT (p = 0.19). Patients with ≥10 involved LNs have similar outcomes following BCT or MRM, suggesting that RT may obviate the need for more-extensive surgery. While local control is comparably favorable regardless of surgical approach, systemic control remains a challenge in this population.

Is a higher boost dose of radiation necessary after breast-conserving therapy for patients with breast cancer with final close or positive margins?

To determine rates of loco-regional recurrence (LRR), distant failure and overall survival for patients with breast cancer treated with breast-conserving therapy (BCT) with a close or positive surgical margin (C/PM) treated with standard dose boost radiation compared with a higher boost of radiation. We retrospectively studied 1476 patients with T1-T3 invasive breast cancer treated with BCT between 1992 and 2009. Median age was 57 years. Patients were divided into three groups: Group I included 1197 patients (81 %) with negative margins who received a standard boost (median 60 Gy) total dose to the lumpectomy cavity; Group II included 116 patients (8 %) with C/PM who received a standard boost (median 60 Gy); and Group III included 163 patients (11 %) with C/PM who received a higher boost (median 68 Gy). Biological subtypes (e.g., ER, PR, HER2/neu) were available for 858 patients (58 %) and were also assessed for any relationship to LRR rate. The Kaplan-Meier, Cox-regression, and log-rank tests were used to estimate rates of LRR and the significance of risk factors. Median follow-up was 8.6 years. The overall 5- and 10-year cumulative incidences of LRR were 2.1 % (95 % CI 0.8-2.1 %) and 4.5 % (95 % CI 3.4-6.0 %), respectively. The 5- and 10-year cumulative incidences of LRR for Group I (negative margins + standard boost) were 1.9 and 4.4 %; for Group II (C/PM + standard boost) were 3.9 and 7.0 %; and for Group III (C/PM + higher boost) were 2.9 and 3.8 %, respectively. No statistically significant differences in LRR rates were found among the three groups (p = 0.4). Similar results were obtained for distant failure (p = 0.3) and overall survival (p = 0.4). On multivariate analysis, tumor grade (p = 0.03), systemic-therapy (p = 0.005), node positivity (p = 0.05), young age (p = 0.001), and biological subtype (p = 0.04) were statistically significantly associated with higher LRR. Higher boost dose and margin positivity were not significant. Our data suggest that the 10-year risk of local recurrence for patients with close or positive margins receiving a standard boost was 7 % compared to 3.8 % for those receiving a higher boost; however, this difference was not significant. A higher boost dose did not significantly improve local control, nor did margins impact LRR risk in our cohort of patients.