Blind Spot in the Radar of MEST-C Score: Type and Severity of Tubulointerstitial Nephritis in IgA Nephropathy.

Background: The updated version of predictive classification for immunoglobulin A nephropathy (IgAN) prognosis "The Oxford Classification" identifies five histopathological features including mesangial hypercellularity (M), endocapillary proliferation (E), segmental glomerulosclerosis (S), tubular atrophy/interstitial fibrosis (T) and crescents (C), the MEST-C. However, few studies suggest that tubulointerstitial inflammation, which is not included in the MEST-C, is also linked to disease progression and is, consequently, a neglected determinant of prognosis among others. Therefore, there is a need to evaluate this histopathological parameter in patients with IgA nephropathy. Materials and Methods: This cross-sectional descriptive study was conducted at Shaukat Khanum Memorial Cancer Hospital and Research Center, Lahore, Pakistan. Data of histopathological and immunofluorescence proven renal biopsies (300) of IgA nephropathy patients from January 2016 through May 2022 were extracted using a convenient sampling technique. Biopsies were histologically reviewed for type and severity of tubulointerstitial inflammation, in addition to the MEST-C score. Renal biopsies of patients who had a history of transplant, autolyzed tissue, no glomeruli on histological examination, and/or a tubular atrophy/interstitial fibrosis score of 2 (T2) in MEST-C scoring were excluded. Data were analyzed using SPSS 20. An association between the variables was analyzed using the chi-square and Fischer exact tests. A p value less than 0.05 was considered statistically significant. Results: A total of 247/300 biopsies were eligible for inclusion. The mean age at the time of biopsy was 31.90 ± 12.48 with 63.6% in the age group between 21 and 40 years, and 69.6% were male. Tubulointerstitial inflammation was observed in 90.2% cases with 49.4% showing moderate while 4.5% showing severe degree of inflammation. A strong association of both the type and severity of tubulointerstitial inflammation was found with M, E, T, and C scores (p value < 0.05). Conclusion: The high-frequency and strong statistical association of tubulointerstitial inflammation with the M, E, T, and C scores in our study elucidate its prognostic role in the progression and management of IgA nephropathy.

Expression of NKX2.2 in Non-Ewing Tumors With Round Cell Morphology.

Background Round cell sarcomas pose diagnostic challenges due to overlapping histopathological features, necessitating precise immunohistochemical markers for accurate categorization. NKX2.2 has emerged as a sensitive diagnostic tool, particularly in Ewing sarcoma. This study extends this understanding to various round-cell sarcomas, shedding light on the potential diagnostic utility of NKX2.2 beyond its established role. The nuanced exploration of NKX2.2 expression aims to enhance diagnostic strategies, prognostic assessments, and therapeutic developments in the landscape of sarcoma research. Methodology Cases were retrieved from the surgical pathology and consultation files of Shaukat Khanum Memorial Cancer Hospital and Research Center, Lahore, Pakistan. Representative hematoxylin and eosin-stained slides of six different types of already confirmed tumors, including lymphoblastic lymphoma, neuroblastoma, rhabdomyosarcoma, synovial sarcoma, Wilms tumor, and Ewing sarcoma, were reviewed by a panel of pathologists. Immunohistochemistry, utilizing a rabbit anti-NKX2.2 monoclonal antibody, was performed on formalin-fixed paraffin-embedded tissue sections. The presence of NKX2.2 was defined as moderate or high nuclear immunoreactivity in at least 5% of cells. Results The histopathological examination revealed characteristic features in each sarcoma subtype, aligning with established diagnostic criteria. In Lymphoblastic lymphoma, T-cell lineage was confirmed through TdT expression, while the atypical finding of focal NKX 2.2 expression hinted at genetic diversity. Neuroblastoma exhibited the expected salt and pepper chromatin pattern, with NKX 2.2 expression raising questions about its prognostic significance. Rhabdomyosarcoma presented primitive cells expressing desmin, and NKX 2.2 focal expression echoed previous subtype-associated studies. Synovial sarcoma displayed both monophasic and biphasic growth patterns and TLE1 expression, with NKX 2.2 variation suggesting tumor heterogeneity. In Wilms tumor, the characteristic WT1 expression was observed, while NKX2.2's absence reaffirmed its irrelevance in this context. Ewing sarcoma displayed the anticipated homogenous cell population, strong NKX2.2 expression, and CD99 positivity across various sites. Furthermore, age and gender impact on this range of sarcomas found no significant relation with an expression of NKX2.2. Conclusion In conclusion, the diverse expression profiles of diagnostic markers discovered in this study, particularly the atypical expression of NKX2.2 beyond its established role in Ewing sarcoma, signify a significant advancement. This unique finding accentuates the potential diagnostic importance of NKX2.2 in various sarcomas, presenting a novel dimension to our understanding of these malignancies.

Angiomatoid Fibrous Histiocytoma: A Tumor With Uncertain Behavior and Various Clinicopathological Presentations.

Background Angiomatoid fibrous histiocytoma (AFH) is a rare soft tissue neoplasm of uncertain differentiation, which has various clinical and morphological presentations. Although it behaves in a benign manner, it has malignant potential. Aim To share various histological patterns and survival data in our population of this rare entity. Materials and methods We studied 25 patients who reported AFH from January 2011 to December 2021. Clinical information, gross and histological features, immunohistochemical results, and survival data were compiled and analyzed. Results Among 25 cases reported as AFH, the majority (68%) were males with a mean age of 31.8 years at the time of diagnosis. The most common location was the lower extremity, especially the thigh (56%), and the mean size of the lesion was 55 mm. Most of the lesions were superficial (84%). Grossly, the majority of lesions (76%) had a solid appearance. Microscopically, classic spindle cell morphology was the most common (76%) with a lymphoid cuff and intralesional hemorrhage. Mild cellular atypia was seen in most (92%) of the cases, while some biopsies (8%) had a high-grade morphology. The majority of patients were alive, while one patient died of the disease. Conclusion AFH is an under-recognized entity with various clinical and histological presentations and a low malignant potential.

The value of histological examination in the diagnosis of tuberculous lymphadenitis in the era of rapid molecular diagnosis.

Extrapulmonary tuberculosis often poses a diagnostic challenge. This study aimed to assess the value of histological examination in diagnosing tuberculous lymphadenitis (LNTB) when performed simultaneously with rapid molecular assay (Xpert MTB/RIF) testing. People presumed to have LNTB were prospectively enrolled in a tertiary care hospital. Excision biopsy was performed and tested by histology, Xpert, and culture. Of 390 lymph nodes, 11 (2.8%) were positive by AFB microscopy, 124 (31.8%) by Xpert, 137 (35.1%) by culture, and histopathology was consistent with TB in 208 (53.3%). Altogether, LNTB was diagnosed in 228 and bacteriologically confirmed TB in 178 cases. Against culture, histopathology versus Xpert had higher sensitivity (93 vs. 62%) but lower specificity (68 vs. 83%). In patients with short clinical history, a significantly higher number of Xpert-positive specimens were culture-positive. Among patients with histology suggestive of TB, no difference was seen in response to treatment between bacteriology positive and negative, but a significant slow response was noted in bacteriology confirmed TB with nonspecific histology. In a country like Pakistan, with high TB and low HIV prevalence, diagnosis is possible for more than 95% of LNTB when Xpert and histopathology examination is used in combination, compared to less than 60% by Xpert alone.

Immunohistochemical expression of CD-10, BCL-6 and MUM-1 antibodies and immediate clinical response in patients of diffuse large B-cell lymphomas after six cycles of chemotherapy.

OBJECTIVE: To determine the expression of CD-10, BCL-6 and MUM-1 in patients with diffuse large B-cell lymphoma (DLBCL) and its association with immediate clinical response after six cycles of CHOP chemotherapy. STUDY DESIGN: Analytical study. PLACE AND DURATION OF STUDY: Armed Forces Institute of Pathology (AFIP), Rawalpindi in collaboration with Nuclear medicine, Oncology and Radiotherapy Institute (NORI), Islamabad from September 2010 to September 2011. METHODOLOGY: CD-10, BCL-6 and MUM-1 antibodies were applied on cases diagnosed as DLBCL. Immediate clinical response was noted after 6 cycles of chemotherapy with the help of oncologist and divided into complete response, partial response, stable disease and relapse/ progression. Patient's age, results of expression of CD-10, BCL-6 and MUM-1 and results of immediate clinical response to chemotherapy were noted. Regarding analysis of prognostic markers (CD-10, BCL-6 and MUM-1), chi-square test was used for immediate clinical response to chemotherapy in DLBCL. RESULTS: CD-10 was positive in 40% cases, BCL-6 in 58.7% cases and MUM-1 was positive in 46.7% cases. About 41.3% of patients showed complete response, 10.6% partial response, 17.3% stable disease and 30.8% showed relapse/progression. CD-10 expression in DLBCL was associated with better immediate clinical response (p=0.011) whereas MUM-1 expression in DLBCL was associated with poor immediate clinical response (p<0.0001). However, there was no statistically significant association of BCL-6 with immediate clinical response (p=0.22). CONCLUSION: DLBCL shows expression of CD-10, BCL-6 and MUM-1 in nearly fifty percent of the cases. CD-10 is associated with good whereas MUM is associated with poor response. However, there was no association of BCL-6 with immediate clinical response.

Determination of frequency of epstein-barr virus in non- Hodgkin lymphomas Using EBV latent membrane protein 1 (EBV-LMP1) immunohistochemical staining.

BACKGROUND: The presence of Epstein-Barr virus (EBV) in Non-Hodgkin's lymphoma can be identified by immunohistochemistry for detection of EBV latent membrane protein (LMP). The role of EBV as an etiologic agent in the development of non-Hodgkin lymphoma has been supported by detection of high levels of latent membrane protein 1 (LMP-1) expression in tumors. However, no study has been conducted in a Pakistani population up till now to determine the frequency of Epstein-Barr virus positivity. The objective of our study was to determine a value for non-Hodgkin lymphoma patients using EBV LMP-1 immunostaining in our institution. MATERIALS AND METHODS: This study was carried out at the Department of Histopathology, Armed Forces Institute of Pathology (AFIP), Pakistan from December 2011 to December 2012. It was a cross sectional study. A total of 71 patients who were diagnosed with various subtypes of NHL after histological and EBV LMP-1 immunohistochemical evaluation were studied. Sampling technique was non-probability purposive. Statistical analysis was achieved using SPSS version 17.0. Mean and SD were calculated for quantitative variables like patient age. Frequencies and percentages were calculated for qualitative variables like subgroup of NHL, results outcome of IHC for EBV and gender distribution. RESULTS: Mean age of the patients was 53.6 ± 16 years (Mean ± SD). A total of 50 (70.4%) were male and 21 (29.6%) were female. Some 9 (12.7%) out of 71 cases were positive for EBV-LMP-1 immunostaining, 2 (22.2%) follicular lymphoma cases, 1 (11.1%) case of T-cell lymphoblastic lymphoma, 4 (44.4%) cases of diffuse large B cell lymphomas, 1 (11.1%) mantle cell lymphoma and 1 (11.1%) angioimmunoblastic T cell lymphoma case. CONCLUSION: In our study, frequency of EBV in NHL is 12.7% and is mostly seen in diffuse large B cell lymphoma. This requires further evaluation to find out whether this positivity is due to co-infection or has a role in pathogenesis.

Prognostic sub-grouping of diffuse large B-cell lymphomas into germinal centre and post germinal centre groups by immunohistochemistry after 6 cycles of chemotherapy.

INTRODUCTION: Diffuse large B-cell lymphomas (DLBCL) can be divided into germinal centre (GC-DLBCL) and post germinal centre (post GC-DLBCL) groups by applying immunohistochemical antibodies. As these subgroups respond differently to chemotherapy, it is possible at diagnosis to select a poor prognostic subgroup for aggressive treatment. OBJECTIVE: To determine the frequencies of GC-DLBCL and post GC-DLBCL in patients by immunohistochemistry (IHC) and the clinical response after six cycles of chemotherapy. SUBJECTS AND METHODS: In this descriptive study conducted in AFIP and CMH, Rawalpindi and NORI, Islamabad, from September 2010 to September 2011, a total of 75 pretreatment cases of DLBCL diagnosed during the study period were included. Cases were segregated in to GC-DLBCL and post GC-DLBCL groups according to results of immunohistochemistry markers CD10, BCL6 and MUM1. Immediate clinical response was assessed after 6 cycles of chemotherapy. Response was divided into complete response, partial response, stable disease or relapse or progression. RESULTS: The mean age was 54.2 ± 15. Males were 53 (70.7%). Forty (53.3%) cases comprised the GC-DLBCL group; 25(62.5%) of them showed a complete response. Most patients of the post GC-DLBCL 19(54%) showed relapse/progression. Results of immediate clinical response in both prognostic subgroups were significant (p<0.05). Results regarding positivity with immunohistochemical antibodies CD10 (p 0.011), BCL6 (p 0.013) and MUM1 (p 0.000) regarding immediate clinical response were also significant. CONCLUSION: GC-DLBCL group shows better response to CHOP chemotherapy regimen. Immunohistochemistry should be used to further classify DLBCL as this can enable us to select aggressive group for aggressive treatment. This manuscript is important because the study is the first to becarried out exclusively in Pakistan or our part of the world.