Cytopathology fellowship recruitment: historical context, current state, and future considerations

Fellowship recruitment and retention of a skilled workforce is one of the biggest challenges that not only cytopathology is facing but that the field of pathology in general is being confronted with. There have long been issues with the fellowship recruitment process for both applicants and fellowship directors, including pressure to move the application process earlier and earlier and frustrations stemming from applicants needing to determine different individual timelines and program requirements. The unified timeline for fellowship recruitment was established as an attempt to standardize the recruitment process and to address the key issues of the push for earlier and earlier decision-making, which placed significant anxiety on trainees, as well as the burden on programs of more unexpected openings. While institution of the unified timeline has had many successes, there have been problems as well. Here, we discuss the multifaceted and intertwined factors that affect fellowship recruitment with a review of the historical context and the current setting and with an eye towards future directions. In the end, the issues we are currently facing are complex and there is likely no perfect solution to fixing an inherently broken system. However, the ultimate goal should be in better supporting our trainees' development and promoting a more fair and equitable recruitment process. Only by working together can we optimize the process for both applicants and programs alike.

The 2023 Bethesda System for reporting thyroid cytopathology

Since the publication of the first edition in 2010, The Bethesda System for Reporting Thyroid Cytopathology has allowed cytopathologists to use a standardized, category-based reporting system for thyroid fine needle aspirations. The third edition builds on the success of the 2 earlier editions and offers several key updates. The most important is the assignment of a single name for each of the 6 diagnostic categories: (i) nondiagnostic; (ii) benign; (iii) atypia of undetermined significance; (iv) follicular neoplasm; (v) suspicious for malignancy; and (vi) malignant. Each of the categories has an implied risk of malignancy (ROM), which has been updated and refined based on data reported after the second edition. The third edition offers an average ROM for each category, in addition to the expected range of cancer risk. The atypia of undetermined significance subcategorization is simplified into 2 subgroups based on the implied ROM and molecular profiling. A discussion of pediatric thyroid disease has been added, and pediatric ROMs and management algorithms are discussed in the relevant sections. Nomenclature has been updated to align with the 2022 World Health Organization Classification of Thyroid Neoplasms. Two new chapters have been added: one that addresses the significant and expanded use of molecular and ancillary testing in thyroid cytopathology, and another that summarizes clinical perspectives and imaging findings in thyroid disease.

Comparison of low-cost phantoms for ultrasound-guided fine-needle aspiration biopsy training

INTRODUCTION

Phantoms and simulators are widely accepted methods to gain valuable experience and confidence for inexperienced trainees prior to seeing their patient and for refining their skills. A phantom model that is durable, simple, and inexpensive to produce and use would be ideal to train practitioners in ultrasound-guided fine-needle aspiration biopsy (USFNA) technique.

MATERIALS AND METHODS

In this study, we systematically compared several low-cost phantom models including gelatin, extra firm tofu, canned cooked pork, ballistics gel, and chicken breast for their haptic properties, echogenicity, teaching utility, and overall performance based on a Likert scale (1-5; 5 = best). Nine cytopathologists and cytopathology fellows who perform FNA regularly evaluated these models and completed the survey.

RESULTS

The gelatin phantom, with a gelatin to water ratio of 1:8 by weight, was found to be the best for USFNA practice and overall performance, followed by the 1:10 gelatin phantom. Tofu and chicken breast phantoms were also good low-cost alternatives that needed only a few minutes of total preparation time.

CONCLUSIONS

Low-cost, homemade phantoms can serve as excellent alternatives to commercial phantoms for practicing and teaching USFNA.

[Cytopathological characterization of ascites for the diagnosis of serous ovarian carcinoma]

Objective: To investigate the cytomorphological and immunocytochemical features of tumor cells in the ascites of ovarian plasmacytoma (SOC). Methods: Specimens of serous cavity effusions were collected from 61 tumor patients admitted to the Affiliated Wuxi People's Hospital of Nanjing Medical University from January 2015 to July 2021, including ascites from 32 SOC, 10 gastrointestinal adenocarcinomas, 5 pancreatic ductal adenocarcinomas, 6 lung adenocarcinomas, 4 benign mesothelial hyperplasia and 1 malignant mesothelioma patients, pleural effusions from 2 malignant mesothelioma patients and pericardial effusion from 1 malignant mesothelioma. Serous cavity effusion samples of all patients were collected, conventional smears were made through centrifugation, and cell paraffin blocks were made through centrifugation of remaining effusion samples. Conventional HE staining and immunocytochemical staining were applied to observe and summarize cytomorphological characteristics and immunocytochemical characteristics. The levels of serum tumor markers carbohydrate antigen 125 (CA125), carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) were detected. Results: Of the 32 SOC patients, 5 had low-grade serous ovarian carcinoma (LGSOC) and 27 had high-grade serous ovarian carcinoma (HGSOC). 29 (90.6%) SOC patients had elevated serum CA125, but the difference was not statistically significant between them and patients with non-ovarian primary lesions included in the study (P>0.05); The serum CEA was positive in 9 patients with gastrointestinal adenocarcinoma and 5 patients with lung adenocarcinoma, and the positive rate was higher than that in SOC patients (P<0.001); The serum CA19-9 was positive in 5 patients with gastrointestinal adenocarcinoma and 5 patients with pancreatic ductal adenocarcinoma, and the positive rate was higher than that in SOC patients (P<0.05). The serum CA125, CEA and CA19-9 were within the normal range in 4 patients with benign mesothelial hyperplasia. LGSOC tumor cells were less heterogeneous and aggregated into small clusters or papillary pattern, and psammoma bodies could be observed in some LGSOC cases. The background cells were fewer and lymphocytes were predominant; the papillary structure was more obvious after making cell wax blocks. HGSOC tumor cells were highly heterogeneous, with significantly enlarged nuclei and varying sizes, which could be more than 3-fold different, and nucleoli and nuclear schizophrenia could be observed in some cases; tumor cells were mostly clustered into nested clusters, papillae and prune shapes; there were more background cells, mainly histiocytes. Immunocytochemical staining showed that AE1/AE3, CK7, PAX-8, CA125, and WT1 were diffusely positively expressed in 32 SOC cases. P53 was focally positive in all 5 LGSOCs, diffusely positive in 23 HGSOCs, and negative in the other 4 HGSOCs. Most of adenocarcinomas of the gastrointestinal tract and lung had a history of surgery, and tumor cells of pancreatic ductal adenocarcinoma tend to form small cell nests. Immunocytochemistry can assist in the differential diagnosis of mesothelial-derived lesions with characteristic "open window" phenomenon. Conclusion: Combining the clinical manifestations of the patient, the morphological characteristics of the cells in the smear and cell block of the ascites can provide important clues for the diagnosis of SOC, and the immunocytochemical tests can further improve the accuracy of the diagnosis.

Monophasic pericardial synovial sarcoma in a turkish female patient: a very rare case with cyto-histopathological findings

BACKGROUND

The aim was to present a 35-year-old female patient with diagnosis of monophasic primary pericardial synovial sarcoma (PSS) with cytopathological findings.

CASE PRESENTATION

The case with back pain, palpitation and weakness, was diagnosed with pericardial effusion and suspicious mass adjacent to right heart in ultrasonography. Computerized tomography showed mass 12 × 11 × 6.5 cm in size, located in right mid-anterior pericardial area, with heterogeneous internal structure, heterogeneously contrasting right heart and prominent pressure on superior vena cava. Cytopathology of pericardial effusion showed monotonous cells with oval-spindle vesicular nuclei, less amphophilic cytoplasm, evenly distributed chromatin and inconspicuous nucleoli. The pericardial mass was resected incompletely, spindle cell mesenchymal tumor with hypercellular fascicular structure and with infiltrative margins, containing a small amount of loose myxoid stroma, occasionally necrotic areas was observed histopathologically. Immunohistochemical positive reaction was for vimentin, Bcl-2, TLE-1. Accordingly, the case was diagnosed with monophasic PSS.

CONCLUSIONS

This case of monophasic primary PSS was an extremely rare malignancy diagnosed with the cytopathological findings.

Lymphoid cell rich fine-needle aspirations of the salivary gland: What is the risk of malignancy?

Objectives

Lymphoid cell rich fine-needle aspirations (FNAs) of the salivary glands pose a diagnostic dilemma, with a wide range of differential diagnoses that include several benign and malignant entities. There is limited literature regarding the entities that are commonly encountered in this situation. Our goal was to characterize the surgical outcome in these cases and to evaluate the risk of malignancy.

Material and Methods

This is a retrospective study at a tertiary care institution. Our database was queried over a 10-year period. FNAs yielding a prominent population of well-visualized lymphoid cells were included in the study. Only cases with surgical follow-up were evaluated. FNAs with epithelial cells, diagnostic features of any entity (such as granulomas or chondromyxoid stroma), history of metastatic malignancy, or scant cellularity were excluded from the study. Lymphoid cells were classified as atypical according to morphologic findings (monomorphism, irregular nuclear contours, and abnormal chromatin patterns). Statistical analysis was performed.

Results

Of the 224 lymphoid cell rich FNAs identified, 29 (28%) had surgical follow-up in our data records. Twenty-two were from the parotid and seven from the submandibular gland. Ten cases (35%) were non-neoplastic (benign lymphoepithelial cyst [n = 4], reactive lymph node [n = 5] and chronic sialadenitis [n = 1]). Benign epithelial neoplasms including pleomorphic adenoma (n = 2) and Warthin's tumor (n = 1) were identified in 10% of the cases. One case with non-atypical lymphocytes proved to be a mucoepidermoid carcinoma (n = 1). Lymphomas were detected in 52% (n = 15). Of note, none of these patients had a history of lymphoid malignancy. 8/15 were low-grade and 7/15 were high-grade lymphoma. Most of these cases (11/15) had atypical lymphocytes on FNA. Ancillary studies were available in a few cases and supportive of the diagnosis of lymphoma, including cell block and immunohistochemistry (n = 7, 47%), flow cytometry (n = 3, 27%), and clonality polymerase chain reaction (PCR) (n = 1; 7%). Most of these were performed in cases with atypical lymphocytes. In cases with non-atypical lymphocytes, five cases were malignant on surgical excision (5/17). Morphology on FNA had a specificity of 92% for malignancy and sensitivity of 69%. The positive predictive value on FNA of atypical lymphocytes for malignancy was 92%.

Conclusion

Lymphoid cell rich FNAs carry a 52% incidence rate lymphoma in our small study population. Specificity of FNA for malignancy is high (92%) and lymphocyte atypia is a strong predictor of malignancy. Ancillary studies may be of added value in FNAs with non-atypical lymphoid cells. FNA has a valuable role in triaging lymphoid lesions of the salivary glands.

Effect of Specimen Processing Technique on Cell Detection and Classification by Artificial Intelligence

OBJECTIVES

Cytomorphology is known to differ depending on the processing technique, and these differences pose a problem for automated diagnosis using deep learning. We examined the as-yet unclarified relationship between cell detection or classification using artificial intelligence (AI) and the AutoSmear (Sakura Finetek Japan) and liquid-based cytology (LBC) processing techniques.

METHODS

The "You Only Look Once" (YOLO), version 5x, algorithm was trained on the AutoSmear and LBC preparations of 4 cell lines: lung cancer (LC), cervical cancer (CC), malignant pleural mesothelioma (MM), and esophageal cancer (EC). Detection and classification rates were used to evaluate the accuracy of cell detection.

RESULTS

When preparations of the same processing technique were used for training and detection in the 1-cell (1C) model, the AutoSmear model had a higher detection rate than the LBC model. When different processing techniques were used for training and detection, detection rates of LC and CC were significantly lower in the 4-cell (4C) model than in the 1C model, and those of MM and EC were approximately 10% lower in the 4C model.

CONCLUSIONS

In AI-based cell detection and classification, attention should be paid to cells whose morphologies change significantly depending on the processing technique, further suggesting the creation of a training model.

Value of cytopathology in the diagnosis of adenoid cystic carcinoma and an analysis of misdiagnoses

BACKGROUND

The diagnosis of adenoid cystic carcinoma (ACC) by cytopathology can be challenging. This study was aimed at testing the effectiveness of this technique and at assessing possible differences in the coincidence rate of fine-needle aspiration cytology(FNAC) and brush exfoliation.

METHODS

The pathology database of Southwest Medical University( Luzhou, China) was searched for patients who had undergone surgery or biopsy for ACC between January 2017 and January 2022 and had preoperative cytopathologic results. Their cytologic and histologic data were then analyzed retrospectively and the coincidence rates of cytopathology in the diagnosis of ACC were calculated.

RESULTS

Compared with histopathology, the total coincidence rate of the cytologic diagnosis of ACC was 76.8%, that of FNAC was 78.9%, and that of brush exfoliation was 55.6%.

CONCLUSION

In the diagnosis of ACC, cytopathology is an effective tool; this is especially true of FNAC, which plays an important role in the diagnosis of ACC. The authors further suggest that it is advisable for diagnosticians to master the cytopathological features of ACC to reduce the possibility of preoperative misdiagnoses.

Artificial intelligence-based tools applied to pathological diagnosis of microbiological diseases

Infectious diseases still threaten the global community, especially in resource-limited countries. An accurate diagnosis is paramount to proper patient and public health management. Identification of many microbes still relies on manual microscopic examination, a time-consuming process requiring skilled staff. Thus, artificial intelligence (AI) has been exploited for identification of microorganisms. A systematic search was carried out using electronic databases looking for studies dealing with the application of AI to pathology microbiology specimens. Of 4596 retrieved articles, 110 were included. The main applications of AI regarded malaria (54 studies), bacteria (28), nematodes (14), and other protozoa (11). Most publications examined cytological material (95, 86%), mainly analyzing images acquired through microscope cameras (65, 59%) or coupled with smartphones (16, 15%). Various deep-learning strategies were used for the analysis of digital images, achieving highly satisfactory results. The published evidence suggests that AI can be reliably utilized for assisting pathologists in the detection of microorganisms. Further technologic improvement and availability of datasets for training AI-based algorithms would help expand this field and widen its adoption, especially for developing countries.

[Serous fluid cytopathology: International system]

The International System for Serous Fluid Cytopathology is a cytologic classification which purpose is to establish a consensus on diagnostic terminology. Five diagnostic categories are proposed associated to an increased rate of malignancy and specific cytological criteria. The categories are reported as: (I) Non-diagnostic (ND), the cells are insufficient for interpretation; (II) Negative for malignancy (NFM), only benign cells are present; (III) Atypia of undetermined significance (AUS), the cells present mild atypia more likely to be benign, but a malignant process cannot be definitively excluded; (IV) Suspicious for malignancy (SFM), the cells are present with atypia or in a number suspect of malignancy but with insufficient ancillary studies to give a positive malignant diagnosis; (V) Malignant (MAL), the cytological criteria are absolutely and definitively malignant. Malignant neoplasia can be primitive, it involves mesothelioma and serous lymphoma but most are secondary and correspond mainly to adenocarcinomas in adults and leukemia/lymphoma in children. The diagnostic should always be provided in the appropriate clinical context and be as definitive as possible. The ND, AUS and SFM are temporary or last intention categories. Immunocytochemistry in association with FISH or flow cytometry allow in most cases a conclusive diagnosis. These ancillary studies as well as ADN and ARN tests on effusion's fluids are particularly suited to give reliable theranostic results for personalized therapies.

A rare case of canalicular adenoma in the parotid gland: Highlighting diagnostic limitations of fine-needle aspiration

BACKGROUND

Canalicular adenoma is a rare, benign tumor of primarily salivary gland origin that presents mostly in the upper lip. However, there are only six reports in the English literature detailing canalicular adenoma of the parotid gland, none of which discuss discrepancy between preoperative cytology and surgical pathology. In this report, we present a rare case of parotid gland canalicular adenoma where preoperative ultrasound-guided fine-needle aspiration (USFNA) suggested malignancy. The patient was treated with deep lobe parotidectomy due to the FNA results and her multiple comorbidities. However, her tumor may have been treated with observation alone if canalicular adenoma had been suspected prior to surgery.

MAIN FINDINGS

A 59-year-old female with a history of heart and lung disease presented with a 1.6 cm well defined, enhancing lesion involving the superficial portion of the right parotid gland. This lesion was incidentally noted on CT angiography (CTA) of the neck and chest. The well-defined characteristics of this lesion on CT imaging suggested benign neoplasm. However, USFNA results were suggestive of a malignant parotid lesion. The patient subsequently underwent right deep lobe parotidectomy with facial nerve dissection and superficial musculoaponeurotic system (SMAS) rotational flap reconstruction. Surgical pathology and immunohistochemistry yielded a final diagnosis of benign canalicular adenoma.

CONCLUSIONS

USFNA diagnosis of CA is extremely difficult due to its low-grade neoplastic cells mimicking neoplastic cells in other benign and malignant tumors of the head and neck. FNA remains a useful tool for assessing malignancy risk, but the results always have some level of uncertainty and do not provide sufficient detail. Therefore, FNA results should be interpreted in concert with imaging and patients' medical history. Cytopathologists can also report salivary gland FNA results in a more uniform and detailed manner by utilizing the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC).

Current state of cytopathology residency training: a Korean national survey of pathologists

BACKGROUND

Although the Korean Society for Cytopathology has developed educational goals as guidelines for cytopathology education in Korea, there is still no systematic approach to cytopathology education status for pathology residents. Furthermore, satisfaction with cytopathology education and with the outcome of the current training/educational program has not been investigated in Korea. This study aimed to obtain comprehensive data on the current state of cytopathology education for residents and evaluate education outcomes.

METHODS

An online survey was conducted in December 2020 for the board-certified pathologists and training residents registered as members of the Korean Society for Cytopathology. The questionnaire comprised questions that investigated the current status of cytopathology at each training institution, the degree of satisfaction with the work and education related to cytopathology, outcomes of cytopathology training, and educational accomplishments.

RESULTS

Of the participants surveyed, 12.3% (132/1,075) completed the questionnaire, and 36.8% (32/87) of cytopathology residents participated. The mean overall satisfaction with cytopathology education was 3.1 points (on a 1- to 5-point scale, 5: very satisfied). The most frequent suggestion among the free description format responses was to expand educational opportunities, such as online education opportunities, outside of the individual institutions.

CONCLUSIONS

Our results showed that cytopathology training in Korea needs further improvement. We expect that this study will inform systematic training of competent medical personnel armed with broad cytopathology knowledge and strong problem-solving abilities.

Pleomorphic hyalinizing angiectatic tumor: FNA analysis of a rare entity and review of the literature

INTRODUCTION

The fine-needle aspiration (FNA) cytopathology of pleomorphic hyalinizing angiectatic tumor (PHAT) is the subject of a very limited number of reports. We undertook a review of our FNA experience with this neoplasm.

MATERIALS AND METHODS

A search was made of our files for PHAT FNA cases with histopathologic confirmation. FNA biopsy smears and cell blocks were performed and examined using standard techniques.

RESULTS

Two primary cases of histologically proven PHAT [both male, ages 56 and 60 years] met study inclusion. FNA sites included buttock and foot. A misdiagnosis of sarcoma was made in each case. Ancillary immunohistochemical testing performed in 1 case suggested angiosarcoma. Cytologic smears showed only modest cellularity with a dual population of bland spindle cells and isolated large pleomorphic cells, many harboring nuclear pseudoinclusions. Smear background was clean, and mitoses absent.

CONCLUSIONS

The imitative cytopathology of PHAT with a pleomorphic sarcoma remains a pitfall in FNA specimens. Awareness of this entity and its lack of hypercellularity, necrosis, and cohesive groups of atypical cells in smears should assist the cytopathologist in avoiding a misdiagnosis of malignancy.

Metastatic sarcomas to pleural effusion: a 10-year large tertiary care center experience with emphasis on clinical features and cytomorphologic characteristics

INTRODUCTION

Metastatic sarcomas to pleural effusion are extremely rare, accounting for <1% of all malignant pleural effusions. We aim to present our experience with pleural effusion specimens containing metastatic sarcomas over a 10-year period.

METHODS

We performed a 10-year retrospective search of cytopathology archives to identify all pleural effusions that were involved by metastatic sarcoma. All available cytopathology and surgical pathology specimens were retrieved and reviewed.

RESULTS

Twenty-eight pleural fluids from 22 patients with metastatic sarcoma were identified in our search. The patients' ages ranged from 12 to 73 years. The pleural fluid volumes ranged from 10 to 1500 ml. Rhabdomyosarcoma was the most commonly encountered metastatic sarcoma to pleural effusion (n = 7). Other metastatic sarcomas were as follows: epithelioid angiosarcoma (n = 4), Ewing sarcoma (n = 3), clear cell sarcoma (n = 2), high grade conventional osteosarcoma (n = 2), undifferentiated pleomorphic sarcoma (n = 1), epithelioid sarcoma, proximal type (n = 1), dedifferentiated liposarcoma (n = 1), and conventional chondrosarcoma (n = 1). The time between initial diagnosis and effusion varied from 3 months to 25 years. Two patients are alive with disease at 6 and 21 months of follow-up. All other patients were dead of disease and the survival after a malignant pleural effusion ranged from <1 month to 18 months.

CONCLUSIONS

Metastatic bone and soft tissue sarcomas to pleural effusions are rare and their cytologic features can be mistaken for carcinoma, melanoma, or mesothelioma. Careful review of the patient's medical history, comparison of the previous pathology and the use of ancillary studies are crucial for the evaluation of pleural effusions involved by metastatic sarcomas.

Minimally Invasive Cytopathology and Accurate Diagnosis: Technical Procedures and Ancillary Techniques

In recent years, the demand for cytopathological accurate diagnoses has increased as expanding minimally invasive procedures obtain materials from patients with advanced cancer for diagnostic, prognostic, and predictive purposes. However, inadequate knowledge of cytopathological technical procedures and ancillary techniques by clinicians remains the most common reason for the limited availability of cytopathology. The objectives of this review were to understand the technical procedures, ancillary techniques, and application and effectiveness of various types of tests in cytopathology. Each of the many ancillary technologies described in the literature has specific advantages and limitations and laboratories select one or more methods depending on their infrastructure and expertise to achieve the goal from initial screening of the disease to the final diagnosis of the cytopathology. This paper systematically reviews the development of cytopathology, summarizes the existing problems in cytopathology and the new progress of auxiliary examination, to provide a theoretical basis for the advanced development of cytopathological diagnostic technologies and to consolidate the minimally invasive and accurate diagnosis of cytopathologies for clinicians. Cytopathology offers many advantages over other clinical examinations, particularly for minimally invasive and accurate diagnosis.

Childhood sarcomas: fine-needle aspiration cytopathology with an emphasis on the use of molecular studies

INTRODUCTION

In children and adolescents, most sarcoma subtypes have a simple karyotype with a single genetic alteration; cytologic findings combined with ancillary testing can lead to a specific diagnosis. The goal of this study was to review the use of fine-needle aspiration in conjunction with immunohistochemistry and molecular studies as a part of an integrated, multidisciplinary diagnostic workup for bone and soft tissue sarcomas in this population.

MATERIALS AND METHODS

We searched for cases aged ≤18 years old with a malignant bone or soft tissue tumor that had corresponding cytology specimens from 3 institutions. Clinical data, cytologic findings and diagnoses, histologic diagnoses, and ancillary testing were documented.

RESULTS

Of 99 cases, 55% were male with a mean age of 12 years. Ninety-four cases (95%) had a specific histologic diagnosis, and 84 cases (85%) were primary neoplasms. Ninety-four cases (95%) had a malignant cytologic diagnosis, and 71 cases (72%) had a specific cytologic diagnosis concordant with the histologic diagnosis. Among primary tumors with a specific histologic diagnosis, a specific cytologic diagnosis was made in 63 cases (79%). After excluding osteosarcoma, 74% of the tumors (n = 50) had molecular studies. Specific genetic alterations supporting a definitive diagnosis were found in 42 cases (84%), the majority of which were demonstrated using Fluorescence In Situ Hybridization (n = 33, 79%).

CONCLUSIONS

We found that fine-needle aspiration in conjunction with core needle biopsy, immunohistochemistry, and molecular studies allowed cytopathologists to accurately classify sarcomas in a pediatric age group.

Molecular testing opportunities on cytology effusion specimens: the pre-analytic effects of various body fluid cytology preparation methods on RNA extraction quality and targeted sequencing

INTRODUCTION

RNA sequencing (RNAseq) analysis is emerging as a clinical research or diagnostic approach for cytologic samples, but there is need for formal comparison of different sample preparation methods in the cytology laboratory to identify which pre-analytic methods could provide alternatives to formalin-fixed paraffin-embedded (FFPE) sections.

MATERIALS AND METHODS

We prepared 13 malignant effusions (metastatic estrogen receptor-positive breast cancer) in the cytology laboratory using 6 routine cytologic methods: FFPE cell block, Carnoy's solution, 95% ethanol (EtOH), air-dried and Diff-Quik, ThinPrep, and SurePath preparations. Measurements of RNA quality, expression of 2 multigene expression signatures, molecular subtype, and 4 common activating mutation sites in each preparation were compared with fresh frozen (FF) cell pellet in RNA preservative using distribution of fragment length and concordance correlation coefficient (CCC).

RESULTS

The fraction of RNA fragments measuring 200 bases or more (DV200) were 24% higher from cytospins fixed in Carnoy's solution or 95% EtOH than DV200 from FFPE cell blocks. SurePath samples failed RNAseq quality control. There was high concordance of gene expression measurements with FF samples using cytospins fixed in Carnoy's solution, 95% EtOH, Diff-Quik (CCC = 0.829, 0.812, 0.760, respectively), or ThinPrep (CCC = 0.736), but lower using FFPE cell block (CCC = 0.564). The proportion of mutant transcripts was concordant between FF and any cytologic preparation methods.

CONCLUSIONS

Cytospin preparations fixed with Carnoy's or 95% ETOH then Papanicolaou stained produced RNAseq results that were equivalent to FF samples and superior to FFPE cell block sections.

A Retrospective Analysis of the Application of the Newly Proposed International System for Reporting Serous Fluid Cytopathology on Serous Effusion Specimens: An Institutional Experience

INTRODUCTION

The International Academy of Cytology and the American Society of Cytopathology recently proposed the International System for Reporting Serous Fluid Cytology (ISRSFC) to standardize serous fluid cytopathology reporting and guide further clinical management. The current study aimed to assess the feasibility of utilizing ISRSFC reporting categories for serous fluids, estimate the risk of malignancy (ROM) of each category, and scrutinize if the management protocols followed in our institution are as per the ISRFSFC recommendations.

METHODS

All pleural, peritoneal, and pericardial effusions submitted for evaluation at our institute between January 2021 and December 2021 were retrieved. All these cases were reviewed and re-categorized into one of the five categories proposed by the ISRSFC: non-diagnostic (ND), negative for malignancy (NFM), atypia of uncertain significance (AUS), suspicious for malignancy (SFM), and malignant (MAL), and ROM was calculated for each category.

RESULTS

The present study examined 596 serous effusions, of which 229 were pleural effusions, 358 were peritoneal effusions, and the remaining nine were pericardial effusions. Among 596 cases, 395 cases had a radiological or histological follow-up. The serous effusion samples were re-categorized as 61 (10.2%) ND, 449 (75.3%) NFM, 47 (7.8%) AUS, 17 (2.9%) SFM, and 22 (3.8%) MAL, and ROM for each above category were 10%, 4.4%, 19%, 83.3%, and 100%, respectively.

CONCLUSION

Categorizing serous effusion cytology samples per the ISRSFC diagnostic categories reduces reporting variability. The ISRSFC provides a standardized format to predict the ROM and thus improves the quality of clinical care.

The Use of the International Academy of Cytology Yokohama System for Reporting Breast Fine-Needle Aspiration Biopsy

OBJECTIVES

To perform the first meta-analysis regarding the pooled risk of malignancy (ROM) of each category of the Yokohama system for reporting breast fine-needle aspiration, as well as assess the latter's diagnostic accuracy using this new system.

METHODS

Two databases were searched, followed by data extraction, study quality assessment, and statistical analysis.

RESULTS

The "Insufficient," "Benign," "Atypical," "Suspicious," and "Malignant" Yokohama system categories were associated with a pooled ROM of 17% (95% CI, 10%-28%), 1% (95% CI, 1%-3%), 20% (95% CI, 17%-23%), 86% (95% CI, 79%-92%), and 100% (95% CI, 99%-100%), respectively. When both "Suspicious" and "Malignant" interpretations were regarded as cytologically positive, sensitivity (SN) was 91% (95% CI, 87.6%-93.5%) and false-positive rate (FPR) was 2.33% (95% CI, 1.30-4.14%). A summary receiver operating characteristic curve was constructed and the pooled area under the curve was 97.3%, while the pooled diagnostic odds ratio was 564 (95% CI, 264-1,206), indicating a high level of diagnostic accuracy. When only "Malignant" interpretations were regarded as cytologically positive, the pooled FPR was lower (0.75%; 95% CI, .39%-1.42%) but at the expense of SN (76.61%; 95% CI, 70.05%-82.10%).

CONCLUSIONS

Despite Yokohama's system early success, more data would be needed to unravel the system's value in clinical practice.

Metastatic salivary gland neoplasms to pleural effusion: diagnostic challenges and prognostic significance in a series with 9 patients

INTRODUCTION

Pleural effusions can present a diagnostic challenge as they are not always caused by malignancy in patients with a history of typical visceral primaries.

MATERIAL AND METHODS

At 2 major academic medical centers, we have identified several cases in which salivary gland neoplasms metastasized to pleural effusions in patients who have been aggressively managed with various treatment modalities including chemotherapy, radiation, and/or surgical excision.

RESULTS

Herein, we present a range of primary salivary gland tumors that metastasized to serous effusions and characterize their cytomorphology, immunoprofiles, and clinical courses. Our case series shows that many tumor types metastasize to pleural effusions and they present unique diagnostic challenges in each case. We found that metastasis of a salivary gland neoplasm to a pleural effusion is a late-stage event and is often associated with poor prognosis.

CONCLUSIONS

This series serves as a resource to demonstrate the cytomorphologic and immunohistochemical features of malignant pleural effusions due to salivary gland neoplasms and draws attention to poor prognosis in cases of salivary duct carcinoma, mucoepidermoid carcinoma and adenoid cystic carcinoma.

Risk of Malignancy Using the Diagnostic Categories Proposed by the World Health Organization International System for Reporting Pancreaticobiliary Cytopathology

BACKGROUND

The World Health Organization (WHO) proposed an updated reporting system for pancreaticobiliary cytology, which moves low-grade malignancies to "positive for malignancy" group and serous cystadenoma to "negative for malignancy" group. The WHO system also created two new categories, namely, pancreatic neoplasia-low grade (PaN-Low) and pancreatic neoplasia-high grade (PaN-High), which includes neoplastic mucinous cysts and stratifies them according to their cytologic atypia. The risk of malignancy (ROM) of the new categories of the WHO system needs to be defined.

METHODS

Cytologic slides of all patients, who underwent endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) biopsy at our institution from January 2010 to December 2021 and had a histopathological or clinical follow-up of at least 6 months, were reviewed and reclassified under the Papanicolaou Society of Cytopathology (PSC) and WHO reporting systems. The absolute ROM was calculated for each category of both reporting systems.

RESULTS

A total of 420 EUS-FNA samples from 410 patients were reviewed and reclassified. The absolute ROM for the proposed WHO system was 35% for "nondiagnostic," 1.0% for "negative for malignancy," 69.0% for "atypical," 11% for "PaN-Low," 100% for "PaN-High," 91% for "suspicious for malignancy," and 100% for "malignant." Comparatively, the absolute ROM under the PSC reporting system was 34% for "nondiagnostic," 1.0% for negative (for malignancy), 50.0% for "atypical," 0.0% for "neoplastic: benign," 16% for "neoplastic: other," 88% for "suspicious for malignancy," and 100% for "positive or malignant."

CONCLUSION

The proposed WHO international reporting system has advantages regarding risk stratification improvement and case management.

Direct Gene Expression Profile Prediction for Uveal Melanoma from Digital Cytopathology Images via Deep Learning and Salient Image Region Identification

Objective

To demonstrate that deep learning (DL) methods can produce robust prediction of gene expression profile (GEP) in uveal melanoma (UM) based on digital cytopathology images.

Design

Evaluation of a diagnostic test or technology.

Subjects Participants and Controls

Deidentified smeared cytology slides stained with hematoxylin and eosin obtained from a fine needle aspirated from UM.

Methods

Digital whole-slide images were generated by fine-needle aspiration biopsies of UM tumors that underwent GEP testing. A multistage DL system was developed with automatic region-of-interest (ROI) extraction from digital cytopathology images, an attention-based neural network, ROI feature aggregation, and slide-level data augmentation.

Main Outcome Measures

The ability of our DL system in predicting GEP on a slide (patient) level. Data were partitioned at the patient level (73% training; 27% testing).

Results

In total, our study included 89 whole-slide images from 82 patients and 121 388 unique ROIs. The testing set included 24 slides from 24 patients (12 class 1 tumors; 12 class 2 tumors; 1 slide per patient). Our DL system for GEP prediction achieved an area under the receiver operating characteristic curve of 0.944, an accuracy of 91.7%, a sensitivity of 91.7%, and a specificity of 91.7% on a slide-level analysis. The incorporation of slide-level feature aggregation and data augmentation produced a more predictive DL model (P = 0.0031).

Conclusions

Our current work established a complete pipeline for GEP prediction in UM tumors: from automatic ROI extraction from digital cytopathology whole-slide images to slide-level predictions. Our DL system demonstrated robust performance and, if validated prospectively, could serve as an image-based alternative to GEP testing.

Clinical Contribution of Standardized Terminology for Pancreatic Lesions' Cytopathology

INTRODUCTION

Demonstration of diagnostic contribution of Papanicolaou Society of Cytopathology-standardized nomenclature for pancreaticobiliary cytology (PSC-PC) in endoscopic ultrasonography (EUS) fine-needle biopsy (FNA) biopsies is important for widespread use and further development.

METHODS

179 EUS-FNA biopsies (89: solid, 90: cystic) and PSC-PC categories were compared with surgical definite histopathology and definite clinical diagnosis. Overall risk of malignancy (oROM) was calculated for each PSC-PC category. Diagnostic accuracy was evaluated.

RESULTS

The cytopathology of lesions was nondiagnostic in 27%. Ductal dilatation, lymphadenopathy, and solid characteristic (independently) were associated with diagnostic result, while lesion size was not. PSC-PC categories had 89% diagnostic consistency with surgical definite histopathology. Category mismatch was detected in 3 patients (11%), of which 2 had adenocarcinoma. oROM was 14.3% for nondiagnostic group, 46% for cat. III (atypia), and 12% for cat. IVB (neoplastic - other). In terms of malignancy, the PSC-PC system had 100% specificity; PPV, 92% sensitivity, and 81% NPV; and the diagnostic accuracy was 94%.

CONCLUSION

Using PSC-PC in EUS-FNA biopsies, pancreatic malignancy can be diagnosed with high diagnostic accuracy. In mucinous cystic lesions, some malignancies may be missed. To predict the malignancy risk of cat. IVB, assessment of dysplasia seems important. Although PSC-PC is not the only parameter in terms of diagnosing malignancy, its contribution to the clinical decision is quite high.

The Diagnostic Challenge of Evaluating Small Biopsies from the Pancreatobiliary System

Examination of fine needle aspirations and small core biopsies of the pancreas can be an extremely difficult and treacherous area for the diagnostic pathologist. The pancreas often yields small and often fragmented specimens, which, in combination with the morphologic overlap between numerous neoplastic and nonneoplastic mimickers, generate multiple potential diagnostic pitfalls. The authors review this challenging topic and provide insight into resolving these pitfalls using morphologic pattern recognition and ancillary testing.

[Molecular cytology: Opportunities and challenges]

Predictive marker (re-)analysis of tumor material can be a real obstacle in several tumor entities, like non-small cell lung cancer (NSCLC), due to difficult anatomic conditions and small biopsy samples. As reported in the literature, cytological samples comprise excellent starting material for predictive marker analysis like fluorescence in situ hybridization and next generation sequencing. As for formalin-fixed paraffin-embedded tissue samples, rigorous quality control and standardized laboratory operating procedures are mandatory. Further advantages of cytological specimens are the rapid and straightforward inspection of representativeness, for example by rapid on-site evaluation (ROSE). Another striking advantage is that the fresh cellular material from smears and serous cavity fluids can be used for the generation of two- and three-dimensional cell culture models. Hereby, in addition to the conventional biomarker testing, complex complementary functional genomic assays can also be applied, for example, to assess the effects of multiple variants in one sample and unknown variants of tumor driver genes and tumor suppressor genes. This information may provide additional vulnerabilities of the tumor to be considered for the therapy decision, for example in the molecular tumor board.