Primitive myxoid mesenchymal tumor of infancy, an enigmatic entity: A case report.

ABSTRACT: Primitive myxoid mesenchymal tumor of infancy (PMMTI) is a rare soft tissue neoplasm of intermediate malignant potential occurring predominantly in infants and younger children. It can show aggressive local infiltration of surrounding structures and frequent relapses but rare metastasis. Morphologically, it is characterized by a proliferation of immature mesenchymal cells in a myxoid background with mild cytologic atypia and branching vessels. The tumor cells demonstrate immunoreactivity with vimentin and BCOR, however, are negative for more specific lineage markers. Its molecular hallmark is BCOR-internal tandem duplication. Previously classified as infantile fibrosarcoma/undifferentiated sarcoma, the association with BCOR-ITD has led to its reclassification as part of a distinct entity-"Sarcoma with BCOR Genetic Alterations"-in the 2020 WHO Classification of Soft Tissue Tumours. Here is a report of a case of a 2-year-old boy with a recurrent scalp mass identified as a primitive myxoid mesenchymal tumor of infancy.

Diagnostic ability of real-time quantitative polymerase chain reaction versus immunohistochemistry for Ki-67 assessment in breast cancer: An Indian perspective.

Background & objectives: Breast cancer is the most common cancer of women. Inferior prognosis in some patients has been attributed to the higher proliferative capability of the tumour. Immunohistochemistry (IHC) for Ki-67, despite being a simple and cost-effective method, has not become a valid tool to evaluate this biomarker. This is ascribed to variation in pre-analytical and analytical techniques, variable expression, hotspot distribution and inter-and intra-observer inconsistency. This study was aimed at defining the analytical and clinical validity of real-time quantitative polymerase chain reaction (RT-qPCR) as an alternative to IHC evaluation. Methods: This study included a total of 109 patients with invasive breast cancers. Ki-67 IHC visual assessment was compared with the mRNA value determined by RT-qPCR. Concordance between both the methods was assessed. Receiver operating characteristic (ROC) curve analysis and Cohen's kappa value with intraclass correlation were performed. Results: The threshold value for Ki-67 by RT-qPCR obtained by ROC curve was 22.23 per cent, which was used to divide breast cancer cases into high proliferative and low proliferative groups. A significant correlation was observed between both the breast cancer groups formed using RT-qPCR threshold as well as median laboratory value of Ki-67 labelling index by IHC. Interpretation & conclusions: The study results showed a significant correlation between the two methods. While IHC is subject to technical and interpretative variability, RT-qPCR may offer a more objective alternative.

Histopathological Significance and Prognostic Impact of Tumor Budding in Colorectal Cancer

Background: Colorectal cancer (CRC) is a heterogeneous disease with a complex etiology. New prognostic factors need to be investigated. Our present focus is on histopathological significance and prognostic impact of tumor budding in CRC. Material and Methods: A total of 60 treatment-naive consecutive patients undergoing surgical resection of CRCs during the period of January 2011 to December 2013 were included in the study. Details of each related to their demographic and tumor profile were recorded. Hematoxylin and Eosin (H and E) and pan-cytokeratin details of each "case" immunohistochemically stained sections were examined for tumor budding assessment along with clinical features. Results: The most frequent site of involvement was the rectosigmoid and sigmoid colon (31.6%). The majority of the cases were moderately differentiated (75%), showed tumor invasion into the pericolic/subserosal fat (66.6%) and stage III (38.3%). Nodal involvement was present in 47%. Correlations between tumor budding and nodal involvement (p-value 0.039) and AJCC stage (p-value 0.021) were found to be statistically significant. Conclusion: Tumor budding is a promising and powerful predictor of lymph nodal metastasis and a higher stage of tumor and can be used as a marker for high-risk CRC. Routine H and E staining aided by cytokeratin immunostaining allows reproducible grading of tumor budding in CRC cases.

Clinical Impact of Mismatch Repair Protein Testing on Outcome of Early Staged Colorectal Carcinomas.

INTRODUCTION: Colorectal cancer is the third most common cancer in men and second most common in women globally. In the present study, we aimed to analyse the proportion of patients with loss of immunostaining for mismatch repair (MMR) proteins in all newly diagnosed stage II cases of colorectal cancer for the purpose of prognostication, for determination of further chemotherapeutic strategy and for familial screening. METHOD: From January 2014 to December 2015, 62 consecutive newly diagnosed cases of stage II colorectal cancer were included in the study. Details of each patient related to their demographic profile and tumour profile were recorded. All the cases were grossed and staged according to College of American Pathologist (CAP) guidelines. The expression of MMR proteins (which was earlier validated on normal as well as tumour tissue) in FFPE tumour tissue using IHC for mut L homologue 1 (MLH1), mut S homologue 2 (MSH2), mut S homologue 6 (MSH6) and post-meiotic segregation increased 2 (PMS2) was studied. Information regarding stage, treatment, clinical outcome and overall survival was retrieved when available. RESULTS: Out of a total of 371 cases, 62 (16.7%) cases were of stage II CRC, out of which 43 (12%) were treatment naive. Among the selected 62 cases, 26 (41.9%) demonstrated loss of MMR proteins and 36 (58.0%) cases had intact nuclear expression. Out of the cases with MMR loss, 38.4% showed loss of MLH1 and PMS2, 30.7% showed loss of MSH2 and MSH6, 26.9% showed isolated loss of PMS2 and 3.8% showed isolated loss of MSH6. Right-sided location (57.6%) was more common than left-sided (19.2%) and transverse colon (23.0%). Majority of the cases were moderately differentiated (65.3%) in morphology. There was no intratumoural infiltrate in most of the cases (53.8%), and only 3.8% cases showed marked intratumoural infiltrate. Also, peritumoural lymphocytic infiltrate was mild to moderate in most of the cases (26.9%) and marked Crohn's-like infiltrate was seen in only 7.6% cases. CONCLUSION: Our study shows that the routine evaluation of MMR proteins is achievable and essential for the purpose of prognostication, planning of treatment strategies and ascertaining a hereditary basis of CRC. The incidence of MMR protein loss was quite high in our study compared to other studies probably due to a difference in ethnicity. Though a right-sided predominance was supported, none of the typical morphological features of microsatellite instability (MSI) tumours were substantiated by our study, highlighting the lack of importance of histology for predicting MSI, and emphasising the point that MSI testing should be done as a routine procedure in all stage II CRC. A short follow-up was done for all our cases and comparison between the survival of the chemotherapy treated MSI cases versus those which were treatment naïve was performed and revealed that chemotherapy (CT) did not provide additional benefit to survival; MSI tumours in general are a better prognostic category and do not require additional chemotherapy.

Histopathological Significance and Prognostic Impact of Tumor Budding in Colorectal Cancer.

BACKGROUND: Colorectal cancer (CRC) is a heterogeneous disease with complex etiology. New prognostic factors for this group of disease need to be investigated. This study evaluated the histopathological significance and prognostic impact of tumor budding in CRC. DESIGN: A total of 60 treatment naive consecutive patients undergoing surgical resection for CRC during the period of January 2011 to December 2013 were included in the study. Details of each patient related to their demographic and tumor profile were recorded. Pan Cytokeratin immunohistochemistry was applied on chosen sections and tumor budding was assessed. RESULTS: The most frequent site of involvement was rectosigmoid and sigmoid colon (31.6%). The majority of the cases were moderately differentiated (75%) in morphology, and showed tumor invasion into the pericolic/subserosal fat (66.6%), and were stage III (38.3%). Nodal involvement was present in 50% cases. Correlations between tumor budding and nodal involvement (p-value 0.039) and AJCC stage (p-value 0.021) were found to be statistically significant. CONCLUSION: Tumor budding may be a promising and powerful predictor of lymphnodal metastasis and a higher stage of tumor and can be used as a marker for assessing the aggressiveness of CRC. Routine hemotoxylin-eosin staining supported by cytokeratin immunostain can aid in the grading of tumor budding in CRC.