Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy, characterized by a range of subtypes that differ in their cytologic features, clinical behavior, and prognosis. Accurate cytologic evaluation of PTC using fine-needle aspiration is essential but can be challenging due to the morphologic diversity among subtypes. This review focuses on the distinct cytologic characteristics of various PTC subtypes, including the classic type, follicular variant, tall cell, columnar cell, hobnail, diffuse sclerosing, Warthin-like, solid/trabecular, and oncocytic PTCs. Each subtype demonstrates unique nuclear features, architectural patterns, and background elements essential for diagnosis and differentiation from other thyroid lesions. Recognizing these distinct cytologic patterns is essential for identifying aggressive subtypes like tall cell, hobnail, and columnar cell PTCs, which have a higher risk of recurrence, metastasis, and poorer clinical outcomes. Additionally, rare subtypes such as diffuse sclerosing and Warthin-like PTCs present unique cytologic profiles that must be carefully interpreted to avoid diagnostic errors. The review also highlights the cytologic indicators of lymph node metastasis and high-grade features, such as differentiated high-grade thyroid carcinoma. The integration of molecular testing can further refine subtype diagnosis by identifying specific genetic mutations. A thorough understanding of these subtype-specific cytologic features and molecular profiles is vital for accurate diagnosis, risk stratification, and personalized management of PTC patients. Future improvements in diagnostic techniques and standardization are needed to enhance cytologic evaluation and clinical decision-making in thyroid cancer.

Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy, characterized by a range of subtypes that differ in their cytologic features, clinical behavior, and prognosis. Accurate cytologic evaluation of PTC using fine-needle aspiration is essential but can be challenging due to the morphologic diversity among subtypes. This review focuses on the distinct cytologic characteristics of various PTC subtypes, including the classic type, follicular variant, tall cell, columnar cell, hobnail, diffuse sclerosing, Warthin-like, solid/trabecular, and oncocytic PTCs. Each subtype demonstrates unique nuclear features, architectural patterns, and background elements essential for diagnosis and differentiation from other thyroid lesions. Recognizing these distinct cytologic patterns is essential for identifying aggressive subtypes like tall cell, hobnail, and columnar cell PTCs, which have a higher risk of recurrence, metastasis, and poorer clinical outcomes. Additionally, rare subtypes such as diffuse sclerosing and Warthin-like PTCs present unique cytologic profiles that must be carefully interpreted to avoid diagnostic errors. The review also highlights the cytologic indicators of lymph node metastasis and high-grade features, such as differentiated high-grade thyroid carcinoma. The integration of molecular testing can further refine subtype diagnosis by identifying specific genetic mutations. A thorough understanding of these subtype-specific cytologic features and molecular profiles is vital for accurate diagnosis, risk stratification, and personalized management of PTC patients. Future improvements in diagnostic techniques and standardization are needed to enhance cytologic evaluation and clinical decision-making in thyroid cancer.

Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy, characterized by a range of subtypes that differ in their cytologic features, clinical behavior, and prognosis. Accurate cytologic evaluation of PTC using fine-needle aspiration is essential but can be challenging due to the morphologic diversity among subtypes. This review focuses on the distinct cytologic characteristics of various PTC subtypes, including the classic type, follicular variant, tall cell, columnar cell, hobnail, diffuse sclerosing, Warthin-like, solid/trabecular, and oncocytic PTCs. Each subtype demonstrates unique nuclear features, architectural patterns, and background elements essential for diagnosis and differentiation from other thyroid lesions. Recognizing these distinct cytologic patterns is essential for identifying aggressive subtypes like tall cell, hobnail, and columnar cell PTCs, which have a higher risk of recurrence, metastasis, and poorer clinical outcomes. Additionally, rare subtypes such as diffuse sclerosing and Warthin-like PTCs present unique cytologic profiles that must be carefully interpreted to avoid diagnostic errors. The review also highlights the cytologic indicators of lymph node metastasis and high-grade features, such as differentiated high-grade thyroid carcinoma. The integration of molecular testing can further refine subtype diagnosis by identifying specific genetic mutations. A thorough understanding of these subtype-specific cytologic features and molecular profiles is vital for accurate diagnosis, risk stratification, and personalized management of PTC patients. Future improvements in diagnostic techniques and standardization are needed to enhance cytologic evaluation and clinical decision-making in thyroid cancer.

Background: While fine needle aspiration cytology (FNAC) plays an essential role in the screening of thyroid nodules, core needle biopsy (CNB) acts as an alternative method to address FNAC limitations. However, diagnosing thyroid CNB samples can be challenging due to variations in background and levels of experience. Effective training is indispensable to mitigate this challenge. We aim to evaluate the impact of an educational program on improving the accuracy of CNB diagnostics. Methods: The 2-week observational program included a host mentor pathologist with extensive experience and a visiting pathologist. The CNB classification by The Practice Guidelines Committee of the Korean Thyroid Association was used for the report. Two rounds of reviewing the case were carried out, and the level of agreement between the reviewers was analyzed. Results: The first-round assessment showed a concordance between two pathologists for 247 thyroid CNB specimens by 84.2%, with a kappa coefficient of 0.74 (indicating substantial agreement). This finding was attributed to the discordance in the use of categories III and V. After peer learning, the two pathologists evaluated 30 new cases, which showed an overall improvement in the level of agreement. The percentage of agreement between pathologists on thyroid CNB diagnosis was 86.7%, as measured by kappa coefficient of 0.80. Conclusions This educational program, consisting of guided mentorship and peer learning, can substantially enhance the diagnostic accuracy of thyroid CNB. It is useful in promoting consistent diagnostic standards and contributes to the ongoing development of global pathology practices.

Background: Core needle biopsy (CNB) improves diagnostic accuracy by providing precise tissue sampling for histopathological evaluation, overcoming the limitation of inconclusive fine-needle aspiration results. This study evaluated the diagnostic performance of CNB in assessing thyroid nodules, with additional analysis of the benefits of BRAF V600E and RAS Q61R immunohistochemical (IHC) markers. Methods: This retrospective study enrolled patients with thyroid nodules who underwent CNB at Dr. Cipto Mangunkusumo Hospital, Jakarta, from July 2022 to July 2024. CNB diagnoses were classified using the Korean Thyroid Association Criteria. Diagnostic efficacy was evaluated for neoplastic and malignant lesions, both independently and with BRAF V600E and RAS Q61R IHC. The correlation between nodule size and postoperative diagnosis was also analyzed. Results: A total of 338 thyroid nodule samples was included, and 52.7% were classified as CNB category II. In the 104 samples with postoperative diagnoses, category IV was the most prevalent (39.4%). CNB demonstrated a sensitivity of 74% and a specificity of 100% for neoplastic lesions and 23.8% sensitivity and 100% specificity for malignant lesions. Combining CNB with BRAF V600E and RAS Q1R IHC increased the sensitivity to 77% for neoplastic lesions and 28.8% for malignant lesions. Larger nodules (>3 cm) were significantly associated with neoplastic (p = .005) and malignant lesions (p = .004). Conclusions CNB performs well in identifying neoplastic lesions, with or without BRAF V600E and RAS Q61R IHC, but its low sensitivity for malignant lesions warrants caution. While CNB categories V–VI indicate malignancy, the possibility of malignancy in categories I–IV should not be overlooked.

Background: Core needle biopsy (CNB) improves diagnostic accuracy by providing precise tissue sampling for histopathological evaluation, overcoming the limitation of inconclusive fine-needle aspiration results. This study evaluated the diagnostic performance of CNB in assessing thyroid nodules, with additional analysis of the benefits of BRAF V600E and RAS Q61R immunohistochemical (IHC) markers. Methods: This retrospective study enrolled patients with thyroid nodules who underwent CNB at Dr. Cipto Mangunkusumo Hospital, Jakarta, from July 2022 to July 2024. CNB diagnoses were classified using the Korean Thyroid Association Criteria. Diagnostic efficacy was evaluated for neoplastic and malignant lesions, both independently and with BRAF V600E and RAS Q61R IHC. The correlation between nodule size and postoperative diagnosis was also analyzed. Results: A total of 338 thyroid nodule samples was included, and 52.7% were classified as CNB category II. In the 104 samples with postoperative diagnoses, category IV was the most prevalent (39.4%). CNB demonstrated a sensitivity of 74% and a specificity of 100% for neoplastic lesions and 23.8% sensitivity and 100% specificity for malignant lesions. Combining CNB with BRAF V600E and RAS Q1R IHC increased the sensitivity to 77% for neoplastic lesions and 28.8% for malignant lesions. Larger nodules (>3 cm) were significantly associated with neoplastic (p = .005) and malignant lesions (p = .004). Conclusions CNB performs well in identifying neoplastic lesions, with or without BRAF V600E and RAS Q61R IHC, but its low sensitivity for malignant lesions warrants caution. While CNB categories V–VI indicate malignancy, the possibility of malignancy in categories I–IV should not be overlooked.

Background: Core needle biopsy (CNB) improves diagnostic accuracy by providing precise tissue sampling for histopathological evaluation, overcoming the limitation of inconclusive fine-needle aspiration results. This study evaluated the diagnostic performance of CNB in assessing thyroid nodules, with additional analysis of the benefits of BRAF V600E and RAS Q61R immunohistochemical (IHC) markers. Methods: This retrospective study enrolled patients with thyroid nodules who underwent CNB at Dr. Cipto Mangunkusumo Hospital, Jakarta, from July 2022 to July 2024. CNB diagnoses were classified using the Korean Thyroid Association Criteria. Diagnostic efficacy was evaluated for neoplastic and malignant lesions, both independently and with BRAF V600E and RAS Q61R IHC. The correlation between nodule size and postoperative diagnosis was also analyzed. Results: A total of 338 thyroid nodule samples was included, and 52.7% were classified as CNB category II. In the 104 samples with postoperative diagnoses, category IV was the most prevalent (39.4%). CNB demonstrated a sensitivity of 74% and a specificity of 100% for neoplastic lesions and 23.8% sensitivity and 100% specificity for malignant lesions. Combining CNB with BRAF V600E and RAS Q1R IHC increased the sensitivity to 77% for neoplastic lesions and 28.8% for malignant lesions. Larger nodules (>3 cm) were significantly associated with neoplastic (p = .005) and malignant lesions (p = .004). Conclusions CNB performs well in identifying neoplastic lesions, with or without BRAF V600E and RAS Q61R IHC, but its low sensitivity for malignant lesions warrants caution. While CNB categories V–VI indicate malignancy, the possibility of malignancy in categories I–IV should not be overlooked.

Background: The diagnosis of thyroid neoplasms necessitates the identification of distinct histological features. Various education/hospital centers located in cities across Indonesia likely result in discordances among pathologists when diagnosing thyroid neoplasms. Methods: This study examined the concordance among Indonesian pathologists in assessing nuclear features and capsular and vascular invasion of thyroid tumors. Fifteen pathologists from different centers independently assessed the same 14 digital slides of thyroid tumor specimens. All the specimens were thyroid neoplasms with known BRAFV600E and RAS mutational status, from a single center. We evaluated the pre- and post-training agreement using the Fleiss kappa. The significance of the training was evaluated using a paired T-test. Results: Baseline agreement on nuclear features was slight to fair based on a 3-point scoring system (k = 0.14 to 0.28) and poor to fair based on an eight-point system (k = –0.02 to 0.24). Agreements on vascular (κ = 0.35) and capsular invasion (κ = 0.27) were fair, whereas the estimated molecular type showed substantial agreement (κ = 0.74). Following the training, agreement using the eight-point system significantly improved (p = 0.001). Conclusions The level of concordance among Indonesian pathologists in diagnosing thyroid neoplasm was relatively poor. Consensus in pathology assessment requires ongoing collaboration and education to refine diagnostic criteria.

Background: The diagnosis of thyroid neoplasms necessitates the identification of distinct histological features. Various education/hospital centers located in cities across Indonesia likely result in discordances among pathologists when diagnosing thyroid neoplasms. Methods: This study examined the concordance among Indonesian pathologists in assessing nuclear features and capsular and vascular invasion of thyroid tumors. Fifteen pathologists from different centers independently assessed the same 14 digital slides of thyroid tumor specimens. All the specimens were thyroid neoplasms with known BRAFV600E and RAS mutational status, from a single center. We evaluated the pre- and post-training agreement using the Fleiss kappa. The significance of the training was evaluated using a paired T-test. Results: Baseline agreement on nuclear features was slight to fair based on a 3-point scoring system (k = 0.14 to 0.28) and poor to fair based on an eight-point system (k = –0.02 to 0.24). Agreements on vascular (κ = 0.35) and capsular invasion (κ = 0.27) were fair, whereas the estimated molecular type showed substantial agreement (κ = 0.74). Following the training, agreement using the eight-point system significantly improved (p = 0.001). Conclusions The level of concordance among Indonesian pathologists in diagnosing thyroid neoplasm was relatively poor. Consensus in pathology assessment requires ongoing collaboration and education to refine diagnostic criteria.