Impact of Histological Type and Grade on the Diagnostic Accuracy of Intraoperative Frozen Section for Detecting Breast Cancer Metastasis to Axillary Sentinel Lymph Nodes.

Introduction Intraoperative sentinel lymph node (SLN) evaluation is the standard of care in patients with clinically node-negative breast cancer. The most common histological subtype of breast carcinoma is invasive ductal carcinoma (IDC), followed by invasive lobular carcinoma (ILC). Alternatively, histological grades vary from grades G1 to G3. Therefore, in this study, we evaluated the diagnostic accuracy of frozen section (FS) for detecting breast cancer metastasis to SLNs with respect to histological subtypes and grades. Methods A retrospective observational study was conducted in the Department of Histopathology at Liaquat National Hospital and Medical College, Pakistan, from January 2013 till December 2020, over a duration of eight years. A total of 540 cases of primary breast cancer, undergoing upfront breast surgery were included in the study. Intraoperatively, SLNs were identified and sent for FS. After FS reporting, the remaining tissue was submitted for final (paraffin) section examination after formalin fixation, and results of FS and final (paraffin) sections were compared. Results The mean age of the patients included in the study was 52.05±12.42 years, and the median number of SLNs was three (ranging from one to 14). The overall sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of intraoperative FS were 88.2%, 100%, 100%, 92.5%, and 95.2%, respectively. The sensitivity of FS for IDC was 88.3%, whereas it was 85.7% for ILC. Alternatively, the sensitivity of FS for grade G1, G2, and G3 tumors was 78.3%, 91.5%, and 90.2%, respectively. The false-negative rate for grade G1 tumors was 21.7%, which was higher than G2 and G3 tumors (8.5% and 9.8%, respectively). Similarly, the false-negative rate for cases where the number of SLNs was more than three was only 5.4%, which was lower than cases with a single and two to three SLNs sent on FS (23.1 and 14.7%, respectively). Conclusion The sensitivity of intraoperative FS for detecting ILC metastasis to axillary SLNs was not substantially different from IDC; however, histological grade affects the sensitivity of FS diagnosis, with lower-grade tumors having low sensitivity. Moreover, increasing the number of SLNs sent intraoperatively on FS improves the sensitivity of FS for detecting breast cancer metastasis to axillary SLNs.

Mutant Phenotype p53 Immunohistochemical Expression Is Associated With Poor Prognostic Parameters and Disease-Free Survival in Triple-Negative Metaplastic Breast Carcinoma.

Introduction Metaplastic breast carcinoma (MBC) is a special type of breast cancer that is most commonly triple-negative and has the worst outcome compared to other breast tumors. p53 is a tumor suppressor gene that is frequently mutated in many human cancers. The association of mutant p53 immunohistochemical expression with clinical and prognostic parameters has not been widely studied in triple-negative MBC. Therefore, in this study, we evaluated the expression patterns of p53 in triple-negative MBC and its association with clinical and prognostic parameters. Methods A retrospective observational study was conducted in the Department of Histopathology at Liaquat National Hospital and Medical College, Pakistan, for a duration of 11 years. A total of 101 cases of triple-negative MBCs were included in the study. p53 immunohistochemistry was performed on the representative tissue blocks. Cases with diffuse strong positive p53 expression were labeled mutant phenotype, while cases with weak patchy p53 expression were termed wild-type. Results The mean age of the patients was 48.33±11.47 years, and the mean tumor size was 3.98±2.07 cm. The mean Ki67 index was 48.98±22.97%. The median disease-free survival of the patients was 24 (three to 68) months, with a median follow-up of 37 (13 to 77) months. Most of the cases were tumor (T)-stage II (51.5%). Axillary metastasis was present in 36.6% of cases, with the perinodal extension in 16.8% of cases. Most cases were non-basal subtype (91.1%), and the majority of cases were grade III (85.1%). Recurrence was observed in 17.8% of cases. Among 101 cases, 52.5% cases showed mutant phenotype p53 expression. A significant association of p53 expression was noted with tumor grade, Ki67 index and disease-free survival. Cases with mutant phenotype p53 expression had a higher tumor grade, higher Ki67 index, and poorer disease-free survival than cases with wild-type p53 expression. Conclusion A substantial proportion of triple-negative MBC expressed diffuse strong expression (mutant phenotype) of p53 in our study, signifying a potential role of p53 as a therapeutic target in triple-negative MBC. Moreover, association of p53 with poor prognostic parameters, such as higher tumor grade and Ki67, and poor disease-free survival underscores the prognostic significance of p53 in triple-negative MBC.

Clinicopathological Features of Craniopharyngioma: A 15-Year Study From a Tertiary Care Center in Pakistan.

Introduction Craniopharyngiomas (CPs) are benign neoplasms and most common suprasellar tumors. They are more frequent in children, contributing to a significant number of intracranial tumors in the pediatric population and are thought to be arising either from the epithelial remnant cells of the craniopharyngeal duct or from the adenohypophysis epithelium. Two subtypes of CPs exist, namely, adamantinomatous craniopharyngioma (ACP) and papillary craniopharyngioma (PCP). ACP is more common in children with a relatively aggressive clinical course and more frequent relapses than PCP. The study objective was to evaluate the clinicopathological features of CP in our population. Methods We conducted a retrospective observational study in the Department of Histopathology at Aga Khan Hospital, Karachi, Pakistan, over a period of 15 years, from January 2001 to December 2015. All CP cases were included in the study. A total of 207 cases were diagnosed during this period by histopathologists based on histologic features. All slides were retrieved, and diagnosis was confirmed after a reexamination of slides. Results We found that the mean age of diagnosis was 25.59±14.71 years, and the median follow-up time was 7 (3-19) years. The number of male patients was 136 (65.7%) and the number of female patients was 71 (34.3%). The most common tumor site was suprasellar (71.5%) followed by the sellar and temporal lobe (12.1% and 6.8%, respectively). The most common complaints were headache (21.7%), followed by loss of vision/decreased vision (16.4%) and vomiting (5.3%). The overall survival rate was 95.2% with a recurrence rate of 5.8%. A significant association of survival was noted with tumor recurrence. Conclusion CP is a rare brain tumor with good overall survival. We found a low recurrence rate of CP in our study. However, recurrence was found to be the most important factor determining survival in patients with CP.

Invasive Papillary Carcinoma of the Breast: Clinicopathological Features and Hormone Receptor Profile.

Introduction Papillary neoplasms are a heterogeneous group of breast lesions, ranging from benign to in situ and invasive malignant tumors. The term invasive papillary carcinoma (IPC) is reserved for rare invasive breast tumors showing greater than 90% papillary morphology. The clinical, epidemiological and pathological characteristics of IPC are not widely described in the existing literature; therefore, in this study, we evaluated the clinicopathological features and biomarker profile of IPC and compared it with invasive ductal carcinoma (IDC) diagnosed in the same study duration. Methods A retrospective study was conducted in the Department of Histopathology, Liaquat National Hospital and Medical College, from January 2013 to December 2020. During the study period, 44 cases of IPC and 1,268 cases of IDC were diagnosed. Slides and blocks of all cases were retrieved and histopathological diagnosis was reviewed. Estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2/neu), and Ki67 immunohistochemical (IHC) stains were applied on representative tissue blocks. Results The mean age of the patients with IPC was 58.77±8.38 years, and the mean Ki67 index was 19.95±21.12%. The mean tumor size was 32.41±17.39 mm, and most tumors (59.1%) were tumor (T)-stage T2. Axillary metastasis was present in 13.6% cases, and 86.4% cases had nodal (N)-stage N0. ER and PR expression was noted in 72.7% cases, and HER2/neu positivity was seen in 13.6% cases. IPC cases had a higher mean age than IDC. Conversely, IPC had a lower mean Ki67 index than IDC. Similarly, IPC cases were found to have a lower frequency of axillary metastasis than IDC. IPC was noted to have a lower frequency of T3-stage and lymphovascular invasion than IDC. A higher expression of PR and lower frequency of HER2/neu expression was noted in IPC than IDC. Conclusion IPC is a rare malignant papillary breast tumor with a wide differential diagnosis and therefore poses a significant diagnostic challenge. We found that IPC had a favorable pathological profile than IDC, in terms of T-stage, Ki67 index, axillary metastasis, PR and HER2/neu expression.