Immunophenotypic analysis of T-acute lymphoblastic leukemia. A CD5-based ETP-ALL perspective of non-ETP T-ALL.

T-cell antigens [CD5,CD1a,CD8] define early T-cell precursor acute lymphoblastic leukemia (ETP-ALL). To understand immature T-ALL of which ETP-ALL is part, we used these antigens to subcategorize non-ETP T-ALL for examining expression of myeloid/stem cell antigens (M/S) and clinical features. Using CD5 (+/-) to start categorization, we studied 69 routinely immunophenotyped patients with T-ALL. CD5(-) was a homogenous (CD8,CD1a)(-) M/S(+) ETP-ALL group (n = 9). CD5(+) cases were (CD8,CD1a)(-) pre-T-ALL (n = 22) or (CD8,CD1a)(+) (n = 38) thymic/cortical T-ALL; M/S(+) 20/22 (90.91%) in former and 22/38 (57.89%) in latter (P = 0.007). ETP- and pre-T-ALL together (CD1a(-) ,CD5(-/+) immature T-ALL group) were nearly always M/S(+) (29/31; 93.55%). In multivariate analysis, only ETP-ALL predicted poor overall survival (P = 0.02). We conclude (i) CD5 negativity in T-ALL almost always means ETP-ALL. CD1a and CD8 negativity, as much as CD5, marks immaturity in T-ALL, and the CD5(+/-) /CD1a(-) /CD8(-) immature T-ALL group needs further study to understand the biology of the T-ALL-myeloid interface. (ii) ETP-ALL patients may be pre-T-ALL if CD2(+) ; CD2(+) , conversely, CD5(-) /CD1a(-) /CD8(-) pre-T ALL patients are ETP-ALL. (iii) Immunophenotypic workup of T-ALL must not omit CD1a, CD5, CD8 and CD2, and positivity of antigens should preferably be defined as recommended for ETP-ALL, so that this entity can be better evaluated in future studies of immature T-ALL, a group to which ETP-ALL belongs. (iv) ETP-ALL has poor prognosis.

Comparative analysis of mutational patterns in triple negative breast cancer before and after neoadjuvant chemotherapy in patients with residual disease.

Triple-negative breast cancer (TNBC) is a heterogeneous disease with poor survival compared to other subtypes. Patients with residual disease after neoadjuvant chemotherapy (NAC) face an increased risk of relapse and death. We aimed to characterize the mutational landscape of this subset to offer insights into relapse pathogenesis and potential therapeutic targets. We retrospectively analyzed archived paired (pre- and post-NAC) tumor samples from 25 patients with TNBC with residual disease using a targeted 72-gene next-generation sequencing panel. Our findings revealed a stable mutational burden in both pre- and post-NAC samples, with a median count of 12 variants (IQR 7-17.25) per sample. TP53, PMS2, PTEN, ERBB2, and NOTCH1 variants were observed in pre-NAC samples predominantly. Notably, post-NAC samples exhibited a significant increase in AR gene mutations, suggesting potential prognostic and predictive implications. No difference in mutational burden was found between patients who did and did not receive platinum (p = 0.94), or between those with and without recurrence (p = 0.49). We employed K-means clustering to categorize the patients based on their variant profiles, aiding in the prediction of possible patterns associated with recurrence. Our study was limited by its small sample size and retrospective design, suggesting the need for further validation in larger prospective cohorts.

Utility of reverse transcriptase - Multiplex ligation-dependant probe amplification (RT-MLPA) in the molecular classification of Diffuse Large B cell lymphoma (DLBCL) by cell-of-origin (COO).

Classifying diffuse large B cell lymphomas, not otherwise specified (DLBCL, NOS), is based on their cell-of-origin (COO) which is included in the WHO classification (2016), is essential to characterize them better in context of prognostication. While gene expression profiling (GEP) considered the gold standard and more recently, the Nanostring-based approach, classify these tumors accurately, many laboratories with limited resources and instrumentation need an alternate approach that is reliable, inexpensive, and with a reasonable turnaround. The Reverse Transcriptase Multiplex Ligation Dependant Probe Amplification (RT-MLPA) to subtype DLBCL, NOS cases, as designed by CALYM group appears to provide a good alternative but needs to be validated in other centres. Therefore, this study evaluated DLBCL, NOS and compared the results of RT-MLPA to that obtained by immunohistochemistry using the Hans algorithm. Materials and Methods: Sixty-five DLBCL, NOS cases were included and the RT-MLPA was set up and standardized using probes that were designed by the CALYM study group. Briefly, RNA was extracted converted to cDNA and the 21-gene expression classifier that also included probes to detect MYD88 mutations and EBER mRNA was performed by MLPA. The results were analyzed by the open home grown software designed by the same group and compared to the results obtained by IHC. Results: Forty-four of the sixty-five cases provided concordant results (k = 0.35) and if the MYD88 results were to be used as a classifier the concordance would have improved from 67.7% to 82%. The 21 discordant cases were divided into five categories to provide a possible explanation for the discordance. Further 26% and 31% of the samples tested were positive for MYD88 mutations and EBER mRNA, respectively. The test had a turnaround of three days. Conclusion: The test provided moderate (67.7%) concordance when compared with IHC and perhaps would have provided higher concordance if compared with GEP. The test also has the advantage of providing information on the MYD88 and EBV infection status. It was found to be reliable, easy to perform and standardize, requiring only routine instruments available in most molecular laboratories. The RT-MLPA assay therefore provides an alternative for laboratories that would require subtyping of DLBCL, NOS cases in the absence of an access to GEP or other instrument intensive methods.

ALK-positive large B-cell lymphomas: A clinicopathologic study.

Background and Aim: Anaplastic lymphoma kinase (ALK)-positive large B-cell lymphomas (ALK+-LBCLs) are aggressive CD20-negative lymphomas, accounting for <1% of diffuse LBCLs. Being rare and with peculiar immunophenotypic characteristics, these can be easily misdiagnosed. We present 11 cases of ALK+-LBCLs diagnosed over a period of 11 years at a tertiary care hospital in South India to analyze the clinical, morphological, and immunophenotypic profile of these tumors. Subjects and Methods: ALK+-LBCL cases diagnosed from September 2009 to August 2020 were included. Clinical details were obtained from stored electronic records and summarized. Available hematoxylin and eosin (H and E) stained slides and immunohistochemistry slides were reviewed and observations tabulated. Results: Eleven patients (nine males and two females) were diagnosed with ALK+-LBCLs in the study period with seven presenting primarily with extranodal disease manifestations. Tumors in the lymph nodes showed diffuse architecture effacement and variable sinusoidal invasion. All tumors showed immunoblastic and plasmablastic-type large lymphoid cells with scattered anaplastic/multinucleate large cells, including rare Reed-Sternberg-like cells. Cytoplasmic granular ALK-1 staining, CD20 negativity, and immunohistochemical features of plasmablastic differentiation were noted in all. Of eight patients treated, only one achieved remission with multi-agent chemotherapy but relapsed after 6 months. Two patients died of disease and five others had progressive/persistent disease and were lost to follow-up. Conclusion: Although rare, these tumors should always be in the differential diagnoses of tumors with plasmablastic and immunoblastic morphology, especially in extranodal sites to avoid diagnostic delay/misdiagnosis.

Comparison of primary follicular lymphoma of gastrointestinal tract and secondary involvement: A study from South India.

Primary follicular lymphoma of the gut (PFL-GI) is a rare entity. This study aims to compare the clinicopathologic features of PFL-GI with cases of gastrointestinal involvement by disseminated nodal follicular lymphoma. This is a retrospective study with 6 cases of primary follicular lymphoma and 8 cases of secondary involvement of the gut, over a period of 9 years. The slides and blocks were retrieved and reviewed. Clinical data was obtained from hospital records. Clinicopathologic features were compared. PFL-GI cases had a slightly higher median age group (p value 0.23) and no gender predilection when compared to cases with secondary involvement which showed a female preponderance. Para-aortic lymphadenopathy was seen in all secondary cases whereas none of the primary cases showed significant lymphadenopathy. The only microscopic feature that was different was the presence of hollowed out pattern of immunostaining for follicular dendritic cells seen in all cases of PFL-GI but in none of the secondary cases.

Image-enhanced endoscopy for real-time differentiation between hyperplastic and fundic gland polyps in the stomach.

BACKGROUND: Fundic gland polyps (FGP) of stomach are benign, while some hyperplastic polyps (HP) may harbor dysplasia or malignancy. Conventional white light endoscopy (WLE) cannot reliably distinguish FGP from HP. We investigated the role of image-enhanced endoscopy in differentiating FGP from HP. METHODS: Patients with gastric polyps were recruited prospectively. The characteristics of the polyps were assessed using WLE and magnification narrow band imaging (mNBI). The microsurface, intervening space (IS), and microvascular (V) features of polyps were evaluated on mNBI. The pattern characteristic of FGP and HP were determined. Histopathology of polyps was the gold standard for diagnosis. Finally, in the validation phase, five endoscopists applied the characteristic features identified in this study to predict the type of gastric polyp and their performance was assessed. RESULTS: Forty-five patients with a total of 70 gastric polyps (HP-46, FGP-24) were included in this study. On mNBI, the pattern characteristic of HP included peripheral curved type of white structures forming large circular/villous loops (microsurface), enlarged intervening space, and microvessels appearing as dark patches in the intervening space (p<0.001 vs. FGP). These were noted in 95.7% HP. In contrast, 95.8% FGP had a pattern characterized by dotted/elliptical/tubular white structures (microsurface), normal width of intervening space, and microvessels surrounding the white structures in a network pattern. This IS-V pattern classification had an accuracy of >90% in the validation phase with intra-class correlation coefficient of 0.95. The accuracy of mNBI was higher than WLE (97.1% vs. 67%) in predicting the type of gastric polyp. CONCLUSIONS: Image-enhanced endoscopy with mNBI (IS-V pattern) performs very well in differentiating HP from FGP.

Neoadjuvant chemotherapy with biosimilar trastuzumab in human epidermal growth factor receptor 2 overexpressed non-metastatic breast cancer: patterns of use and clinical outcomes in India.

BACKGROUND: Human epidermal growth factor receptor 2 (HER2)-positive breast cancer is associated with poor prognosis and access to anti-HER2 treatment is still a challenge in lower-middle income countries. The availability of the biosimilar trastuzumab has improved access by lowering the costs. We report the pattern of use of neoadjuvant ± adjuvant trastuzumab and outcomes in patients with HER2-positive non-metastatic breast cancer treated with regimens incorporating shorter durations of therapy and the use of the biosimilar trastuzumab compared to the innovator. METHODS: We conducted a retrospective analysis of patients with non-metastatic HER2-positive breast cancer treated with neoadjuvant ± adjuvant trastuzumab (innovator (n = 34 (33%)) and biosimilar (n = 70 (67%)) manufactured by Biocon Biologics) with chemotherapy. Information regarding chemotherapy regimens, duration of trastuzumab use (≤12 weeks and >12 weeks), pathological response (Miller Payne grade), disease free survival (DFS), overall survival (OS) and safety data were collected from electronic medical records. RESULTS: A total of 135 patients were analysed with a median age of 51 years (range: 23-82); of these, 57% were postmenopausal, 31.8% were hormone receptor positive and 62.9% had stage III disease. The overall pathological complete response (p-CR) in both breast and axilla increased to 37.6% in patients treated with trastuzumab preoperatively as compared to 22.2% in patients who did not receive any trastuzumab. Patients receiving innovator trastuzumab and biosimilar trastuzumab showed a p-CR of 28.5% and 41.7%, respectively. At a median follow-up of 42 months (range: 3-114), there were 18 relapses and 11 deaths. The 3-year DFS was 87.1% and OS was 92.2%. Cardiac dysfunction developed in 4 of 78 (5.1%) evaluable patients. CONCLUSION: Access to anti-HER2 therapy in the treatment of non-metastatic HER2-positive breast cancer in resource-constrained settings has improved significantly with the availability of the biosimilar trastuzumab. Imbalances in patient profiles at baseline in routine clinical practice led to inconclusive outcomes of ≤12 weeks versus >12 weeks trastuzumab treatment. However, on the basis of historical data, patients could be offered shorter duration of trastuzumab when a standard 1-year treatment of adjuvant trastuzumab is not feasible in resource-constrained settings. The p-CR using the biosimilar trastuzumab in neoadjuvant treatment has been observed to be comparable to the innovator trastuzumab.

Lymphomatoid granulomatosis: A case series from South India.

CONTEXT: Lymphomatoid granulomatosis (LYG) is a rare B-lymphoproliferative disorder characterised by an angiocentric and angiodestructive pattern along with Epstein - Barr virus (EBV) association. It is one of the diagnostic challenges in lymphoma pathology. Deregulation of EBV immune surveillance is one of the narrated hypotheses in the literature. Extrapulmonary manifestations are rare with LYG. Morphological grading is done based on the number of EBV-positive B cells, which is useful to strategize treatment protocol. AIMS: We report here a series of nine cases of LYG to discuss the clinical, histological, and immunohistochemistry findings. SETTINGS AND DESIGN: This is the first case series from India in published literature. SUBJECTS AND METHODS: We reviewed cases of LYG diagnosed at our center for the past 11 years (2006-2016). A total of nine cases were included in this study. Histomorphology was studied in conjunction with immunohistochemistry and clinical details. Cases without classical morphology and negative for EBV immunostain were excluded from the study. RESULTS: There were nine patients in our study (7 males and 2 female; M:F ratio 3.5:1). The age of these patients ranged from 4 years to 57 years (mean age: 30 years). The most common site involved was the lung (4, 44%), followed by the skin (2, 22%), central nervous system (2, 22%) and lymph node (1, 11%). One patient had primary immunodeficiency. Another patient had undergone renal transplant 11 years before the development of the lesion. Angiocentricity and angioinvasion were appreciated in all nine cases (9/9) with necrosis in four cases (44%) and ill-defined histiocytic aggregates in three cases (33%). The histological features were as follows: Grade 1(4 cases, 44%), Grade 2(2 cases, 22%), and Grade 3(3 cases, 33%). CONCLUSION: LYG is a rare EBV driven angiodestructive disease with predominantly lung involvement as well as isolated extrapulmonary sites as seen in our study. It is often progressive and ultimately fatal in the absence of appropriate treatment. Grading of the lesion helps to initiate the appropriate treatment of choice.

Renal cell carcinoma presenting as a cutaneous horn and nodules on the gingiva and scalp.

A 63-year-old man presented with a pulsatile cutaneous horn on the nose and multiple angiomatous nodules on the gingiva and scalp, which appeared over 2 months. He had severe hypercalcaemia, lytic lesions in multiple bones and acute kidney injury. Excision biopsy from the gingival nodule showed a clear cell neoplasm. The bone marrow showed atypical cells with similar morphology. Imaging showed a 7 cmx7.5 cm mass at the upper pole of the left kidney with metastases to the bones, liver and lung. Immunohistochemistry was consistent with metastatic renal cell carcinoma. Renal cell carcinoma presenting as a cutaneous horn is extremely rare and to the best of our knowledge only one other case was found in the literature. There was visible regression in the size of the cutaneous horn and nodules following initiation of pazopanib therapy. However, he succumbed to his illness a month later.

Malignant Peripheral Nerve Sheath Tumour of the Small Bowel Presenting with Intussusception and Perforation: a Double Jeopardy?

Malignant peripheral nerve sheath tumours (MPNST) are rare soft tissue sarcomas which largely occur in the extremities and the head and neck region. The tumours are aggressive with a high rate of recurrence. Radical surgical resection remains the treatment of choice with adjuvant radiation therapy and chemotherapy still failing to demonstrate a clear benefit. The gastrointestinal tract is an exceedingly rare site for these tumours. We report an unusual case of a young male with an MPNST of the small bowel who presented with an ileocolic intussusception and sigmoid perforation.

Old but Still Relevant: High Resolution Electrophoresis and Immunofixation in Multiple Myeloma.

INTRODUCTION: High resolution electrophoresis (HRE) and immunofixation (IFX) of serum and urine are integral to the diagnostic work-up of multiple myeloma. Unusual electrophoresis patterns are common and may be misinterpreted. Though primarily the responsibility of the hematopathologist, clinicians who are responsible for managing myelomas may benefit from knowledge of these. In this review article we intend to discuss the patterns and importance of electrophoresis in present day scenario. METHODS: Patterns of HRE and IFX seen in our laboratory over the past 15 years were studied. RESULTS: Monoclonal proteins are seen on HRE as sharply defined bands, sometimes two, lying from γ- to α-globulin regions on a background of normal, increased or decreased polyclonal γ-globulins, showing HRE to be a rapid and dependable method of detecting M-protein in serum or urine. Immunofixation complements HRE and due to its greater sensitivity, is able to pick up small or light chain bands, not apparent on electrophoresis, including biclonal disease even when electrophoresis shows only one M-band. Special features liable to misinterpretation are discussed. Familiarity with the interpretation of the varied patterns seen in health and disease is essential for providing dependable laboratory support in the management of multiple myeloma.

AML transformation after autologous stem cell transplant for multiple myeloma.

A 59-year-old male patient was diagnosed as multiple myeloma in 2005 and received chemotherapy consisting of thalidomide, cyclophosphamide, and dexamethasone. The patient subsequently received high-dose melphalan followed by autologous stem cell transplantation and maintenance therapy with thalidomide. During the follow-up, the patient developed fever and cytopenias in 2012. The work up revealed 55% blasts in the marrow with myeloid phenotype leading to a diagnosis of acute myeloma leukaemia (AML). The karyotype was normal (46,XY) on conventional cytogenetics. The therapy was initiated, however, the patient expired within 1 month of diagnosis. The treatment related factors like alkylating agents are usually taken as the responsible agents for therapy-related AML, however, recent studies have proposed a multifactorial pathogenesis of leukaemic transformation in multiple myeloma.