Myeloid sarcoma: Experience from a tertiary care center in southern India - A series of eight unusual cases.

BACKGROUND: Myeloid sarcoma (MS) is a tumor mass comprising myeloid blasts with or without maturation occurring in any site other than bone marrow. It is a rare and distinct clinical presentation of myeloid neoplasm. MATERIALS AND METHODS: This is a retrospective study over 7 years (2015-2022) comprising a series of eight cases, which includes clinical details, morphology, immunohistochemistry (IHC) markers, cytogenetics, and molecular details. RESULTS: These cases showed up as an isolated MS (3/8), as an initial clinical presentation in acute myeloid leukemia (1/8), as acute myeloid leukemia (1/8), as a disease progression in primary myelofibrosis (1/8), as chronic myeloid leukemia (1/8), and as BCR-ABL-negative myelodysplastic syndrome/myeloproliferative neoplasm (1/8). One of the three isolated MS was incorrectly identified as having Ewing's sarcoma. One case each presented at the cervical lymph node, mediastinum, skin, sacral soft tissue, maxillary sinus, and perinephric fat, and two cases presented at the hard palate. CONCLUSION: Four of the cases in our study were clinically thought of as lymphoma/sarcoma, which was a major diagnostic challenge. All but one case succumbed to their disease. Without adequate clinical history and appropriate use of ancillary techniques such as IHC in tissue biopsies, flow cytometry, cytogenetics, and molecular studies, these cases have a high chance of being misdiagnosed as non-Hodgkin lymphoma, small round blue cell tumor, or undifferentiated carcinomas, which can complicate patient management and prognosis.

The Difficulties and Ease of Diagnosing Anaplastic Large Cell Lymphomas on Cytology.

Introduction and Objectives: Anaplastic large cell lymphoma (ALCL), a unique non-Hodgkin lymphoma (NHL), is a CD30-positive neoplasm of T-cell lineage. Its distinctive yet variable cytomorphology makes diagnosing fine needle aspiration cytology (FNAC) challenging. This study was undertaken to study the cytomorphology and the utility of immunocytochemical (ICC) stains on cytology in ALCL and to discuss their morphological differential diagnosis. Materials and Methods: The present study was conducted in the Department of Pathology of a tertiary care center. A retrospective review was done from January 2017 to July 2022, and all histopathologically and immunohistochemically (IHC) diagnosed cases of ALCL were taken and correlated with the cytological diagnosis. Results: Twenty-one cases of histopathology examination and IHC-proven cases of ALCL were retrieved from the departmental archives and reviewed. The ages ranged from 3 to 80 years (median age 28 years). Commonly noted cytomorphologic features included singly dispersed large pleomorphic cells, hallmark cells, and Reed-Sternberg-like cells. CD15, CD30, epithelial membrane antigen, and anaplastic lymphoma kinase-1 were some of the ICC stains used in this study. All 21 cases had cytology correlation. Fourteen cases had concordant cyto-histological correlation. Seven cases of histopathologically proven ALCL were reported as Hodgkin lymphoma (HL) in three, ALCL/anaplastic diffuse large B-cell lymphoma, HL/ALCL, poorly differentiated carcinoma, and NHL in one case each on cytology. Conclusion: ALCL has a reasonably distinct cytomorphologic appearance and ICC staining pattern, and a careful interpretation of both helps arrive at a reliable FNAC diagnosis.

Flow Cytometric Assessment of CD26-Positive Leukemic Stem Cells: A Rapid and Valuable Tool in the Diagnosis and Follow-Up of Chronic Myeloid Leukemia.

Context Chronic myeloid leukemia (CML) is a clonal myeloproliferative neoplasm. Recent studies have suggested that CD26-positive leukemic stem cells (LSCs) circulating in peripheral blood are specific for CML. Objective This study was undertaken to determine the proportion of CD26-positive LSCs at diagnosis and its change during tyrosine kinase inhibitor therapy. Design This prospective study was conducted on 43 cases of CML at diagnosis. For flow cytometry, peripheral blood cells were stained with CD45, CD34, CD38, CD3, and CD26. A sequential gating strategy with CD45/SSC (side scatter), CD34/SSC, and CD34/CD38 was applied to identify CD45+/34+/38- populations, from which CD26-positive stem cells were identified and compared with controls. Data analysis was done with Kaluza software. Results All patients diagnosed with CML were detected with CD26-positive LSCs. The median percentage of CD26-positive CML LSCs was 0.02 with a range of 0.001 to 1.77. None of the control samples showed CD26 positivity. The percentage and absolute count of CD26-positive CML LSCs were reduced after six months of tyrosine kinase therapy in patients with complete hematological remission. Conclusion Flow cytometric analysis of circulating CD26-positive CML LSCs is a non-invasive, rapid, and useful tool in the diagnosis and follow-up of CML.

The urgency of Burkitt lymphoma diagnosis in fluid cytology-A tertiary care experience.

BACKGROUND: Burkitt lymphoma (BL) is an aggressive high-grade B-cell non-Hodgkin lymphoma commonly diagnosed in young age and is known to involve extra nodal sites. But the involvement of body fluids by BL is an uncommon presentation. Rapid diagnosis of BL is vital to prevent complications like tumour lysis syndrome. Cytological examination of body fluids continues to be an indispensable tool for rapid diagnosis of BL. OBJECTIVES: In this study, we aim to study the clinical, cytomorphological and immunophenotypic characteristics of BL involving serous effusions and other fluids. MATERIALS AND METHODS: In this retrospective study, 17 cases reported as BL in fluid cytology from 2016 to 2022 were collected and reviewed. We performed a comprehensive analysis of the clinical data, cytomorphological features, immunophenotyping data along with the haematological workup of these cases. We have also compared with the histopathological diagnosis for those cases where biopsy was available. RESULTS: BL more commonly involved ascitic fluid (52%), followed by pleural fluid (4 cases) and cerebrospinal fluid (CSF; 4 cases). Primary diagnosis of BL in fluid was done in 88% of the cases. Bone marrow involvement was noted in two cases. Cytological smears showed discrete monomorphous population of medium-sized atypical lymphoid cells with frequent apoptotic bodies. Classic cytoplasmic punched out vacuoles were observed in 88% of the cases. Immunophenotyping data was available for 12 cases in which tumour cells showed positivity for CD20 (100%), CD10 (4 of 7 cases), BCL6 (3 of 5 cases) and cMYC (7 of 7 cases-100%) and were negative for Terminal deoxynucleotidyl transferase (TdT) (11 of 11 cases). Mean Ki67 labelling index was 95%. Histopathological diagnosis was available for 9 cases, and there was 100% agreement between cytological and histopathological diagnosis in 7 cases. CONCLUSION: Precise diagnosis of BL can be rendered in body fluids by identification of classic cytomorphological features and by performing supportive ancillary tests in fluids for immunophenotyping.

Autoimmune Hemolytic Anemia in Children: Clinical Profile and Outcome.

OBJECTIVE: To discover the common triggers for AIHA in children, their clinical profile, treatment response, and outcome. METHODS: This was an ambispective descriptive study conducted between 2013 and 2020. Children aged 1 mo to 14 y with hemolytic anemia and a positive direct antiglobulin test (DAT) were included. Children with a positive DAT but without any clinicolaboratory evidence of hemolysis were excluded. Data were collected from a structured pro forma with particulars comprising clinicolaboratory profile, treatment administered, and disease outcome. RESULTS: A total of 46 children (aged between 1 mo and 14 y) were enrolled in the study. The mean age of onset was 8.7 (± 4.34) y, and 24 (52.8%) were males. Secondary causes were observed in 29 (63%) cases, while the primary cause was found in 17 (37%). Systemic lupus erythematosus (SLE) was the common trigger in 13 (45%) cases, followed by malignancy in 4 (14%) cases. Pallor (98%), hepatomegaly (72%), and splenomegaly (48%) were the most commonly observed clinical signs. The mixed immunophenotype was observed in 27 (59%) cases, followed by warm type in 12 (26%) and cold agglutinin type in 7 (15%) cases. All children received glucocorticoid therapy, and mycophenolate mofetil was commonly used as second-line therapy in 15 (33%) cases. 13 cases (71%) of primary AIHA and only 4 (14%) cases of secondary anemia achieved complete remission. Overall, 7 children (15%) died, all belonging to secondary AIHA. CONCLUSION: Secondary AIHA was more common than primary in the present study, and SLE was the standard trigger. Primary AIHA carries a better prognosis than secondary.

Quantification of circulating clonal plasma cells by multiparametric flow cytometry as a prognostic marker in patients with newly diagnosed multiple myeloma.

BACKGROUND: Studies have shown that the quantification of circulating clonal plasma cells (cCPCs) in peripheral blood using flow cytometry could be used as a prognostic predictor of poor outcome in multiple myeloma (MM). METHODS: In 66 newly diagnosed MM, cCPCs were quantified (cCPC%) and analysed for association with outcome and survival. Single-tube combined surface (CD45/CD19/CD138/CD38/CD56/CD27/CD81 as per availability) and cytoplasmic (kappa/lambda) staining was done using pre-titrated volumes of antibodies. In 26 patients, repeat cCPC% was assessed post-induction therapy. For association studies, treatment response has been taken as good (VGPR and above) and poor (PR and below). All statistical analyses were performed with SPSS software version 16.0. RESULTS: There was no significant association between cCPC% at baseline with staging (p = 0.43), ß2 -microglobulin (p = 0.27) and albumin (p = 0.08). There was a significant difference between the pre-induction and post-induction cCPC% (p = 0.0001). The patients were segregated using a cut-off of ≥0.197 and <0.197 based on the median values of baseline cCPC%. The post-induction outcome was available for 47 patients among whom 33 (70%) had VGPR and above. There was a significant association between higher cCPC% at baseline with poor treatment response (p = 0.008). The median OS in the study patients was 42 (CI 28.14-43.03) months and the median PFS was 39 (CI 28.49-49.04) months. Higher cCPC% showed a lower median PFS (30 vs. 39 months) and OS (35 vs. 41 months) compared to lower cCPC% though it was not statistically significant. CONCLUSION: Flow cytometric baseline cCPC% in newly diagnosed MM was associated with poor treatment response and survival.

Efficacy and safety of pomalidomide, bortezomib, and dexamethasone combination chemotherapy for newly diagnosed multiple myeloma: POMACE Phase II Study.

Bortezomib, lenalidomide, and dexamethasone induction chemotherapy (VRd), followed by autologous stem cell transplantation (ASCT), are the standard of care for patients with newly diagnosed multiple myeloma (NDMM). Pomalidomide is currently approved for relapsed-refractory multiple myeloma. This single-arm, open-label, phase 2 study was the prospective evaluation of the efficacy and safety of bortezomib, pomalidomide, and dexamethasone (VPd) induction for NDMM. We used Fleming's two-stage design for sample size calculation. We included transplant-eligible and ineligible patients aged 18-75 years in the study. The patients received four cycles of VPd induction followed by response assessment. Thirty-four patients were included in the study, of which 31 completed all four cycles of induction. The median age was 52 years (32-72). Thirty (91%) patients had multiple myeloma, and three had multiple plasmacytomas with less than 10% bone marrow involvement. Nine (27%) had ISS-I, 9 (27%) had ISS-II, and 15 (46%) had ISS-III myeloma. Three patients had high-risk cytogenetic abnormalities. After four cycles of VPd induction, ten patients (32%) achieved stringent CR, nine had CR (29%), eight (26%) had VGPR, and 4 (13%) had PR. Fifteen (48%) had a complete metabolic response (CMR) on PET-CT. Two patients developed SAEs. Anemia was the most common hematological toxicity. Peripheral neuropathy and constipation were the most common non-hematological toxicities. Patients with ≥VGPR had significantly better 12-month PFS than those with PR. Patients with ≥VGPR and CMR on PET-CT had significantly better 12-month OS. Our study showed VPd induction is safe and efficacious in NDMM. Further Phase 3 studies are necessary to establish the superiority and survival benefits.

Clinicopathological Spectrum of Cutaneous Lymphomas and Distinction of Early Mycosis Fungoides from its Mimics-A Retro-Prospective Descriptive Study from Southern India.

Background: Cutaneous lymphomas (CLs) could be either primary (PCL) or secondary; the former comprises cutaneous T-cell lymphomas (CTCLs) and cutaneous B-cell lymphomas (CBCLs). Mycosis fungoides (MF) is the most common PCL. Diagnosis of early MF and distinguishing it from benign inflammatory mimics is challenging. This study aims to assess the clinicopathological spectrum of CL and to characterize early MF from its mimics using clinical characteristics, histopathological features, and ancillary techniques. Materials and Methods: This retro-prospective descriptive study was conducted in a tertiary-care institute, for over 5 years. Clinically as well as histopathologically suspected and biopsy-proven CL and their mimics were included. Cases were reviewed and subgrouped based on clinical and histopathological parameters and immunohistochemistry (IHC). Data were analyzed using descriptive statistics and a Chi-square test at a 5% level of significance. Results: Among PCL, CTCL comprised 84% (21/25) and CBCL was 16% (4/25); the most common CTCL was MF at 81% (17/21). Histologically, atypia of dermal infiltrate (100%), epidermotropism (91.7%), basal alignment of lymphocytes (91.7%), clear haloed cells (91.7%), wiry collagen (66.7%), grandiosity sign (50%), eccrine infiltration (66.7%), and follicular infiltration (50%) were significantly associated with early MF. Spongiosis (84.6%), pigment incontinence (84.6%), exocytosis (76.9%), and parakeratosis (76.9%) were significantly associated with inflammatory mimics. There was no significant difference in the downregulation pattern of CD7 (P = 0.206) between early MF and its mimics. The four cases of CBCL in our study were plasmablastic lymphoma, diffuse large B-cell lymphoma, follicular lymphoma, and lymphoblastic lymphoma. Conclusion: MF was the most common PCL. Histological parameters showed a significant difference, whereas IHC did not show any significant difference between early MF and its mimics.

An observation of a potential metastatic mimic in bone marrow aspirate smears.

We present an interesting observation of crushed erythroid precursors in bone marrow aspirate smears mimicking metastatic deposits. These artefactual clusters could be due to anticoagulation with ethylenediaminetetraacetic and also due to shearing forces exerted on the cells during aspiration and smearing. It is important to be aware of this potential mimic as in a given clinical context it can get misdiagnosed as metastasis.

Post-chemotherapy Changes in Bone Marrow in Acute Leukemia With Emphasis on Detection of Residual Disease by Immunohistochemistry.

Introduction In acute leukemia, the leading cause of treatment failure is disease relapse leading to a low level of complete remission and short overall survival. Post-chemotherapy marrow examination gives vital clues regarding treatment response and marrow regeneration. Aim We aimed to study the histomorphological changes in post-chemotherapy bone marrow in acute leukemias, monitor residual disease by immunohistochemistry (IHC) on trephine biopsy, and correlate survival status. Method This study was a prospective clinical study. A total of 155 post-induction cases (acute myeloid leukemia [AML] - 68 and acute lymphoblastic leukemia [ALL] - 87), from January 2014 to December 2015, were included with a follow-up of 4-28 months. A detailed histomorphology was studied in all cases. IHC was applied in 88 cases of post-induction marrow, which showed morphologic suspicion of an increase in blasts. Observations Post-induction marrow was hypercellular in 55.9% of AML and normocellular in 56.3% of ALL. Regenerative hematopoiesis was noted in 37.4% of AML and 88.5% of cases of ALL. Marrow serous atrophy and stromal edema were associated with delayed recovery of counts and their recovery duration ranged from one to five months. Twenty-seven bone marrow aspirates were unsatisfactory, and their trephine biopsies were showed remission in 20 cases and stromal changes in nine cases. In addition, trephine biopsy picked up residual leukemic blasts in four cases in which aspirate showed remission status. Post-induction marrow IHC with scattered positivity for blasts showed sustained remission in 96% cases, and in those with clustered positivity, 28.6% showed residual disease, and 7.2% showed relapse at the end of the study period. The median survival duration was 13, 3, and 12 months for cases with sustained remission, residual disease, and relapse, respectively. There was a statistically significant difference in median survival of patients in the three groups (sustained remission, residual disease, and relapse) (p=0.000). Conclusion We conclude that histomorphology augmented by IHC on trephine biopsy gives valuable information regarding post-chemotherapy changes and residual disease status. Bone marrow trephine biopsy is an important tool to assess the remission status of patients with acute leukemia.

The utility of fine needle aspiration cytology in orbital haematolymphoid neoplasms.

BACKGROUND: Orbital hematolymphoid lesions are rare and usually encountered in elderly patients. Orbital lesions are not easy to biopsy: hence fine needle aspiration cytology (FNAC) can be a very good diagnostic modality for these lesions. MATERIALS AND METHODS: Cases of orbital masses subjected to FNAC dating from 2013 to 2020 were retrieved from our archives. A total of 16 cases with biopsy confirmation were included. All clinical details, the type of procedure, details of the immunocytochemistry (ICC) performed on smear, follow-up biopsy, and their haematological work-up were analysed in detail. RESULTS: Sixteen biopsy-confirmed cases had been diagnosed as orbital haematolymphoid lesions on cytomorphology and further categorised with ancillary studies including ICC. In twelve instances, the cytology impression was congruent with the histopathological diagnosis and eight of the sixteen cases (50%) proved to be primary orbital lymphoma. Four were secondary orbital lymphomas and the remaining four included one case each of plasmacytoma, myeloid sarcoma, Rosai-Dorfman disease and angiolymphoid hyperplasia with eosinophilia. CONCLUSION: FNAC is a minimally invasive procedure for diagnosing most of the haematolymphoid orbital lesions and it has a rapid turnaround time. The accuracy of cytomorphology combined with ICC on smears/cell blocks can be as good as a biopsy for exact categorisation. Additionally, aspirate smears are preferred samples for cytogenetics compared to formalin-fixed tissue blocks, as molecular cytogenetics techniques are frequently employed for diagnostic, prognostic, and therapeutic purposes.

Langerhans' Cell Histiocytosis Masquerading as Caroli's Disease.

Langerhans' cell histiocytosis is an uncommon disease in children with varied clinical presentation. Multisystem form of this disorder usually affects organs like the bones, skin, liver, spleen, lungs, and the central nervous system. We describe here the clinical details of a 2-year-old girl with involvement of unusual sites like the parotid glands and the nails. This child also had multiple cystic lesions in the liver leading to a misdiagnosis of Caroli's disease. Knowledge about the uncommon manifestations of this rare disorder helps in early diagnosis and treatment.

Highlights of Abstracts on Lymphoma in the Annual Conference ISHBT Kochi 2018.

Lymphomas constitute a vast and heterogenous group of predominantly solid haematopoietic malignancies. Immunohistochemistry has always played a pivotal role in the diagnosis of lymphomas. Many new prognostic immunohistochemical markers have also come up and are being increasingly employed. The unraveling of molecular pathways in the study of lymphomas has opened the possibility of various new prognostic markers. Staging of lymphomas relies a lot on imaging. With the increasing use of positron emission tomography/computerized tomography scan for staging, many studies have shown that it has a high sensitivity for detecting bone marrow (BM) involvement especially in Hodgkin lymphoma thereby obviating the need for BM biopsy. Treatment option though heavily chemotherapy-regimen based, relapsed/refractory lymphomas pose a therapeutic challenge despite the advent of salvage chemotherapy, monoclonal antibodies and stem cell transplantation. Response rates to therapy also show a great deal of variation. The 59th Annual Conference of ISHBT "Haematocon" 2018 held at Kochi, Kerala had 27 abstracts which included 17 case series and 10 case reports presented under the lymphoma track. This brief review summarizes the salient findings as a reflection of on-going studies on lymphoma from various parts of our country.

Role of Immunohistochemistry in Acute Leukemias with Myelonecrosis.

Myelonecrosisis a rare antemortem finding most commonly seen in haematopoeitic neoplasms, especially in acute leukemia. When myelonecrosis occurs at the time of presentation, it imposes certain diagnostic issues in sub categorization of leukemias which is necessary for therapeutic as well as prognostic purposes. Flow cytometry, though is a powerful modality, has its own limitations especially when the cells are not fresh and viable; and when the specimen is not of adequate cellularity which is usual in cases of myelonecrosis. In such situations, immunocytochemistry (ICC) or immunohistochemistry (IHC) may play a major role in lineage specification in leukemias as the necrosed marrow with the ghost cells can still retain the antigenicity for certain immunomarkers. Four such interesting cases of common B acute lymphoblastic leukemia (ALL) where IHC was used for diagnosis were included. ICC and IHC done on the necrosed marrow contributed to the diagnosis of ALL in all the four cases and contributed to subsequent management. ICC and IHC if contributory can play a major role in identifying the primary cause of myelonecrosis as the ghost cells can retain the antigenicity despite being morphologically non-viable.

Utility of p57 immunohistochemistry in differentiating between complete mole, partial mole & non-molar or hydropic abortus.

BACKGROUND & OBJECTIVES: There is considerable inter-observer variability in the diagnosis of molar pregnancies by histomorphological examination of products of conception (POC). The p57KIP2 gene is paternally imprinted and expressed from the maternal allele. On immunohistochemistry (IHC) with p57, complete mole (CM) shows absent staining whereas hydropic abortus (HA) and partial mole (PM) show positive staining. This study was undertaken to evaluate the role of p57 IHC along with histomorphology in differentiating between CM, PM and non-molar or HA. METHODS: This was a cross-sectional study over a period of three and a half years on archival material. Detailed histomorphological review along with p57 IHC was carried out in 28 diagnosed cases (23 CM, 4 PM and 1 molar pregnancy not categorized) and 25 controls of four normal placentas and 21 POC (8 non-hydropic and 13 HA). RESULTS: In 14.8 per cent (4/27) cases, there was discordance in accurate subtyping of molar pregnancy. One case of CM showed inconsistent IHC pattern. In 15.4 per cent (2/13) HA, molar pregnancy was final diagnosis. After final review, there were 25 CM, five PM, 22 non-molar controls including 10 HA and one not assigned (PM/HA). IHC with p57 was negative in 96 per cent CM and positive in 100 and 95 per cent PM and non-molar controls, respectively. INTERPRETATION & CONCLUSIONS: This study showed that negative p57KIP2 immunostaining reliably identified CM and could be used in association with the histological findings to distinguish CM from its mimics.

Composite lymphoma with coexistence of diffuse large B-cell lymphoma and anaplastic large cell lymphoma: Diagnostic pitfalls.

Composite lymphoma is a rare tumor composed of two or more distinct lymphomas in the same topographic site or tissue. Several combinations of B-cell non-Hodgkin lymphoma (NHL), T-cell NHL, and Hodgkin lymphoma can occur with different prognoses and treatments. The coexistence of a B-cell NHL and a T-cell NHL is unusual. The exact etiology of composite lymphoma is unknown; however, few mechanisms have been proposed to explain its pathogenesis. The chemotherapeutic protocols are heterogeneous but are essentially targeted against the high-grade component. Most of the cases show worse outcome with a median survival of 12 months. In this article, we report a case of composite lymphoma which was initially diagnosed as diffuse large B-cell lymphoma, and the presence of CD3-positive atypical cells in the bone marrow urged us to re-evaluate the lymph node biopsy following which a focus of Alk-1-positive anaplastic large cell lymphoma was identified.