Major Nerve Resections in Extremity Soft Tissue Sarcomas-Functional and Oncological Outcomes.

Soft tissue sarcomas form 1% of all cancers and are rare. The lower limb is one of the commonest sites of sarcoma, with the thigh accounting for the majority of these tumors. Large tumors abut the neurovascular bundles both anteriorly and in the hamstring compartment. Nerve involvement, especially the major nerves such as the femoral and the sciatic, by these tumors, was considered to be an absolute contraindication for limb salvage procedures. We present our data of major nerve resection without amputation, in an attempt to demonstrate the possibility of equivalent functional and oncological outcomes in these rare tumors. A total of 86 cases of extremity soft tissue sarcomas were operated on during the period September 2019 to September 2022, of which there were 12 cases of major nerve resections of the lower extremity. These patients were followed up and their clinicopathological data collected and analyzed. The functional outcome was recorded at different intervals. Of the 12 patients who underwent nerve resection along with the tumor, only 1 patient developed a local recurrence. Two patients developed multiple lung metastases, and the other 9 patients are alive and free of disease, with a median follow-up of 26 months. The MSTS score was assessed at 1 month post-surgery, 3 months, 6 months, and 1 year post-surgery. Except for one patient where the score was 20%, all the other patients had scores of 80% or more. Major nerve involvement by soft tissue sarcomas is not an indication for amputation. Limb salvage can be performed with no effect on the oncological outcomes.

A Comprehensive Correlation of Clinicopathologic Prognostic Factors in Malignant Adult Renal Tumors: A Single Institutional Study.

OBJECTIVE: To study the clinicopathologic prognostic parameters of malignant adult renal tumors as these have poor over-all survival (OS) and show frequent metastasis. MATERIAL AND METHODS: This was a retrospective analysis of the clinical and pathologic features of malignant renal tumors in adult patients from January 2011 to December 2020. All the tumors were studied with respect to age, clinical presentation, tumor type/subtype, histologic grade (WHO/ISUP grading system), TNM stage and presence of necrosis. Correlation of histopathologic features and survival analysis was done using Kaplan-Meier survival curves and Cox-regression analysis. RESULTS: A total of 257 cases were included in the study period including 253 renal cell tumors of which clear cell renal cell carcinoma accounted for 69.3%. The age of the patients ranged from 20 to 87 years (median-52 years). The overall survival significantly reduced with increasing histologic grade, stage, and presence of necrosis. The comparison between the histological subtypes was not statistically significant. Univariate Cox-regression analysis found significant hazard ratio with increasing age, size, histologic grade (G4 vs G1), stage, and presence of necrosis. The correlation of OS with histological subtypes was not significant. Multivariate analysis also showed increased hazard ratio with increasing age, size, grade, and stage. However, the P-value was significant only for age. CONCLUSION: Clear cell renal cell carcinoma was the commonest type of adult renal tumor. Older age at presentation, larger tumor size, presence of necrosis, and higher histologic grade and stage were associated with poor prognosis in these patients.

Clinicohistoradiological and surgical outcome in diffuse midline glioma.

PURPOSE: Diffuse Midline Glioma (DMG) with H3K27M mutation is a rare and aggressive midline high grade glioma with a predominant astrocytic differentiation and K27M mutation in either H3F3A or HIST1H3B/C. This tumor is more common in children than in adults. The current study was aimed to determine clinicohistoradiological and surgical outcome of patients who have undergone surgery for DMG and study disease severity of patients with DMG. METHODS: This is an observational study in which 29 DMG patients were evaluated for clinicohistoradiological and surgical outcomes by assessing the pre and postoperative neurological status. RESULT: Survival duration was significantly high in patients with age > 18 years (p = 0.02). Patients who had undergone Radiation Therapy showed higher survival rate (p = 0.05) and the cases with low levels of Ki 67 index had improved post operative outcome (p = 0.002). CONCLUSION: DMG with H3K27M mutation in newly classified Central Nervous System tumor are WHO grade IV Tumors, comprising H3K27M mutation as molecular marker for diagnosis and related with a poor prognosis.

A Clinical and Immunopathological Analysis of Carcinoma of the Ovary with an Emphasis on Post-chemotherapy Histopathologic Changes.

Ovarian cancers are a heterogeneous group of malignant tumors that differ with respect to pathogenesis, morphology, molecular features, and behavior. Pathologists and clinicians need to be aware of the advances in diagnosis and the changes which occur after chemotherapy to offer the optimal treatment to each patient. The present work aims to study the morphologic and immunohistochemical (IHC) profile of primary ovarian cancers with an assessment of post-chemotherapy changes. A total of 51 cases were included in the study from June 2017 to June 2019 (prospective and retrospective). The demographic and clinical details of the patients were collected. The gross and microscopic features of the tumors were studied, and the post-chemotherapy changes were evaluated. A chi-square test was used to determine the association of tumor morphology, the chemotherapy response score (CRS), and stage of the tumor with survival (PFS and OS). The mean patient age was 47.5 years, and high-grade serous carcinoma (66.6%) (HGSC) was the most common subtype followed by mucinous carcinoma and endometrioid carcinoma. Immunohistochemical analysis with WT1 and p53 helped in the diagnosis of HGSC. The CRS was 1 and 2 in most of the cases. The follow-up for patients of HGSC was available for a period of 1-27 months with a mean survival for primary resection of 24 months and for post-NACT resection was 17 months. This difference was not statistically significant (p = 0.38). High-grade serous carcinoma was the most common ovarian cancer in our series, and immunohistochemistry played an important role in the diagnosis. We could not demonstrate any survival benefit of preoperative chemotherapy in our series.

Hepatocellular carcinoma: A clinicopathological and immunohistochemical study of 116 cases from a tertiary care hospital in Southern India.

Background: Diagnosis of hepatocellular carcinoma (HCC) is difficult on morphology alone in poorly differentiated tumors and metastatic carcinomas. Appropriate immunohistochemical markers are required for definite diagnosis. In this article, we have analyzed the histopathological and immunohistochemical features of HCC and elucidate the best possible immunohistochemistry (IHC) marker combination by comparing the sensitivity of various markers in different grades of tumor. Methods: A total of 116 consecutive cases were analyzed retrospectively. The hematoxylin and eosin stained sections were reviewed in all the cases. IHC was done using hepatocellular specific antigen (HSA), arginase-1, glypican-3, and polyclonal carcinoembryonic antigen (pCEA). The sensitivity of various immunohistochemical markers individually as well as in combination for different tumor grades was determined. Results: Histologically, the predominant subtype comprised of classic variant (109,93.9%) followed by combined hepatocellular and cholangiocarcinoma (4,3.4%) and fibrolamellar variant (3,2.6%). Trabecular pattern was the most common histological pattern. On grading, 65,56.03% were moderately differentiated, 34,29.31% well differentiated, and17, 14.65% poorly differentiated. HSA and polyclonal-CEA showed higher sensitivity than arginase-1 and glypican-3 in well and moderately differentiated tumors. In contrast arginase-1 and glypican-3 showed better sensitivity in poorly differentiated HCC. The overall sensitivity increased to greater than 90% if HSA/polyclonal-CEA is combined with either arginase-1/glypican-3 irrespective of tumor grade. Conclusion: Majority of the tumors were classic variants and moderately differentiated. HSA along with either arginase-1 or glypican-3 is the best combination of immunomarker for identification of hepatocellular differentiation irrespective of tumor grade.

Impact of macroscopic on-site evaluation on the diagnostic outcomes of endoscopic ultrasound-guided fine-needle aspiration.

BACKGROUND: Endoscopic ultrasound (EUS)-guided tissue acquisition is the preferred modality for diagnosing pancreatic lesions and mediastinal and abdominal lymph nodes. Rapid on-site cytologic evaluation improves the diagnostic outcome of EUS-guided fine-needle aspiration (FNA) but is unavailable at many centers. Alternatively, macroscopic on-site evaluation (MOSE) may improve the diagnostic outcome of EUS-FNA, but data are limited. Hence, the present study was conducted to assess the efficacy of MOSE in improving adequacy and accuracy. METHODS: We retrospectively analyzed data of consecutive patients with pancreatic or lymph nodal lesions undergoing EUS-guided FNA at a tertiary care center from December 2020 to December 2022. The study's primary outcomes were adequacy and diagnostic accuracy of the EUS-guided tissue acquisition, with secondary analysis of predictors of adequacy and accuracy. RESULTS: Data from 124 patients (44.4% male, median age: 54 years) who underwent EUS-FNA were included in the present analysis. The presence of macroscopic visible core (MVC) on MOSE was reported in 93/124 (75%) cases. An adequate sample for histopathological or cytological examination was obtained in 110/124 (88.7%) cases, while the diagnostic accuracy was 85.5%. On multivariate analysis, the absence of MVC on MOSE was found to be the independent negative predictor of both adequacy (OR 0.092, 95% CI: 0.024-0.349) and accuracy (OR 0.175, 95% CI: 0.057-0.536). CONCLUSION: The presence of MVC on MOSE can be an indicator of specimen adequacy and can improve the diagnostic yield of EUS-FNA.

Primary Hepatic Choriocarcinoma with Pregnancy: A Diagnostic and Therapeutic Challenge.

Choriocarcinoma occurs mainly in the gonads, but an extragonadal origin has been reported, albeit infrequently. Primary hepatic choriocarcinoma (PHC) is a rare malignancy, with only 11 cases reported. Most cases reported were in males, with none reported in pregnant females. A 23-year-old primigravida presented with a large liver lesion involving the right lobe of the liver at 28 weeks of pregnancy. Preoperative imaging was suggestive of hepatocellular carcinoma. She underwent a non-anatomical resection of the liver lesion. Surprisingly, her postoperative histopathology revealed a diagnosis of PHC. Her blood workup showed elevated beta human chorionic gonadotrophin. She underwent a termination of her pregnancy at 32 weeks. Before initiating adjuvant chemotherapy four weeks after surgery, a whole-body PET scan revealed multiple bi-lobar liver and pelvic deposits. After a multidisciplinary team discussion, she was started on adjuvant chemotherapy. She is currently under regular follow-up, seven months post-surgery. PHC, one of the vascular lesions of the liver, poses a diagnostic and therapeutic challenge, warranting a multidisciplinary approach.

Genetics and muscle pathology in the diagnosis of muscular dystrophies: An update.

Muscular dystrophies are a clinically and genetically heterogeneous group of disorders involving the skeletal muscles. They have a progressive clinical course and are characterized by muscle fiber degeneration. Congenital muscular dystrophies (CMD) include dystroglycanopathies, merosin-deficient CMD, collagen VI-deficient CMD, SELENON-related rigid spine muscular dystrophy, and LMNA-related CMD. Childhood and adult-onset muscular dystrophies include dystrophinopathies, limb-girdle muscular dystrophies, Emery-Dreifuss muscular dystrophy, facioscapulohumeral muscular dystrophy, and myotonic dystrophy. Traditionally, muscle biopsy and histopathology along with special pathology techniques such as immunohistochemistry or immunoblotting were used for the diagnosis of muscular dystrophies. However, recent advances in molecular genetic testing, especially the next-generation sequencing technology, have revolutionized the diagnosis of muscular dystrophies. Identification of the underlying genetic basis helps in appropriate management and prognostication of the affected individual and genetic counseling of the family. In addition, identification of the exact disease-causing mutations is necessary for accurate prenatal genetic testing and carrier testing, to prevent recurrence in the family. Mutation identification is also essential for initiating mutation-specific therapies (which have been developed recently, especially for Duchenne muscular dystrophy) and for enrolment of patients into ongoing therapeutic clinical trials. The 'genetic testing first' approach has now become the norm in most centers. Nonetheless, muscle biopsy-based testing still has an important role to play, especially for cases where genetic testing is negative or inconclusive for the etiology.

Hepatic epithelioid hemangioendothelioma-report of three cases of a puzzling tumor.

Hepatic epithelioid hemangioendothelioma (EHE) is a rare malignant vascular neoplasm with unpredictable clinical behavior. These lesions are frequently misdiagnosed owing to its non-specific symptomatology, ambiguous radiological features, and overlapping histomorphology. We report three cases of hepatic EHE, of which one was male and two were female patients. While all three patients presented with abdominal pain, the male patient gave an additional history of weight loss and was jaundiced. The radioimaging showed multiple nodules in the liver and two of the patients also had pulmonary metastasis. The biopsies of the liver nodules revealed a tumor composed of spindle, epithelioid, and stellate tumor cells, some with characteristic intracytoplasmic vacuolations/lumina surrounded by myxohyaline stroma. Some of these intracytoplasmic vacuoles/lumina showed erythrocytes, suggesting its vascular origin which was confirmed by CD31 and CD34 positivity. The article highlights the importance of histopathology and IHC in the precise diagnosis of EHE.

Revisiting Vasculopathy in Lupus Nephritis: A Renal Biopsy Evaluation Study.

Introduction: The classification of lupus nephritis (LN) on biopsy is essentially focused on morphologic changes in glomeruli. Renal vascular lesions are not addressed in detail in current classifications and are often overlooked. We aimed to determine the prevalence of vascular lesions in LN on biopsies and to compare these with biopsies not showing the vasculopathies. Methods: A total of 740 renal biopsies of LN were analysedfor presence of vasculopathies from January 2013 to June 2019. Of these, 527 (71.2%) biopsies showed vascular lesions (vascular group), which were further categorized into known five subtypes according to morphology and immunofluorescence (IF) findings. Remaining 213 (28.8%) biopsies constituted non-vascular group. Clinical, demographic and laboratory parameters were compared between these two groups. Results: The mean age was 27.95 ± 9.8 years and 27.0 ± 9.4 years in the vascular and non-vascular groups respectively with higher M:F (1:2 > 1:7) in vascular group. Majority of vasculopathies (257, 48.7%) were found in biopsies with class IV LN. Haematuria (69.8% vs. 20.1%), proteinuria (100% vs. 62%), anemia (48.3% vs. 3.60%) and hypertension (39.8% vs. 8.46%) were common in group I. Uncomplicated vascular immune deposits (426; 80.8%) were the most common vasculopathy and true vasculitis (4;0.8%) was least common. Activity and chronicity indices (7.35 ± 3 and 2.45 ± 1.5, respectively) were significantly higher in the vascular group. Activity index was highest in uncomplicated vascular immune deposits (7.45 ± 2.8) and chronicity index was highest in non-specific sclerotic vascular lesions (2.7 ± 1.6). Conclusion: Vascular involvement is common in LN. Uncomplicated vascular immune deposits were common vasculopathies whereas true vasculitis was least common. The morphology and IF both need to be carefully screened for the diagnosis of vasculopathies.

Bone Marrow Metastasis of Solid Tumors: A Study of 174 Cases Over 2 Decades from a Single Institution in India.

To analyze the pathological findings in patients with marrow metastasis from solid tumors and to compare the accuracy of the bone marrow aspirate, trephine imprint and trephine biopsy in detecting metastasis. A total number of 174 cases diagnosed on bone marrow aspiration and/or bone marrow biopsy from January 2000 to December 2018 were included in the study. In addition to clinical and demographic data, we evaluated peripheral blood findings, and pattern as well as morphology of the tumor cells in bone marrow aspirate, imprint cytology and biopsy. The changes in the bony trabeculae were classified according to the classification of carcinomatous osteodysplasia. The most common laboratory findings included cytopenias and leucoerythroblastic blood picture. Trephine biopsy was found to be the most sensitive technique for detection of marrow metastases with a sensitivity of 99.4%. Trephine imprint cytology (89.9%) showed a significantly better detection rate than bone marrow aspiration (58.5%). Metastatic adenocarcinomas and undifferentiated carcinomas were more common than non-epithelial tumors. Metastatic carcinomas with known primary were mostly from breast, prostate and lung. Ewings/PNET and neuroblastoma were the commonest among metastatic non-epithelial tumors. Fibrosis (53.4%) was the most frequent stromal change and abnormalities in bony trabeculae were noted in 61.2% cases. Trephine biopsy has the highest sensitivity in detection of marrow metastasis followed by trephine imprint cytology. Immunohistochemistry on trephine section will help in confirming and or suggesting the primary tumor in unknown cases.

Bone metastases: A compilation of 365 histologically verified cases spanning over two decades from a single center.

OBJECTIVE: To analyze the clinicopathological features of metastatic bone tumors over a period of two decades and identify the primary site of malignancy in metastasis of unknown origin. MATERIALS AND METHODS: A total number of 365 cases were included in the study. The clinical features and location of the tumors were noted. The histopathological features of all the cases were studied. Immunohistochemistry (IHC) was done either to categorize or confirm the primary diagnosis using organ specific/organ restricted markers. RESULTS: A total 712 bony sites were involved by metastasis in 365 patients, of which spine was the most commonly affected. Metastasis was the initial presentation in 69.5% patients. The primary site was known in 220 patients and almost half of them were detected after the diagnosis of metastasis. IHC was used as adjunct to suggest the possible origin in cases with unknown primary in 27.4%. Among the metastatic carcinoma, adenocarcinoma was the most common histological subtype with thyroid being the most frequent primary site of origin followed by lung and breast. CONCLUSION: More than two-third of cases in surgical pathology practice present as initial manifestations. Detection rate of primary depends on extent of metastatic work-up and IHC with organ specific/organ restricted markers to facilitate treatment with bone targeting agents.

Sporadic Inclusion Body Myositis: A Clinicopathological Study.

BACKGROUND: Sporadic inclusion body myositis (s-IBM) is rare in India. AIM: The aim of this study was to diagnose s-IBM according to the European Neuromuscular Center (ENMC) IBM research diagnostic criteria 2011. MATERIALS AND METHODS: A retrospective review of patient records diagnosed as s-IBM according to the above criteria during the period from January 2010 to May 2015 was done with an emphasis on pattern of muscle weakness.Serumcreatine kinase (CK) andelectromyography (EMG) were noted. Muscle biopsy was evaluated with basic panel of histochemical stains including Congo red stain. Immunohistochemistry (IHC) with ubiquitin was done in 10 biopsies. IHC for major histocompatibility complex-1 and electron microscopy studies were not performed. RESULTS: The diagnosis of s-IBM constituted 5 clinicopathologically defined, 12 clinically defined, and 10 probable IBM in the study period. There was male predominance with median age at 51 and duration of disease varying from 1-5 years. All the patients presented with insidious onset of muscle weakness of quadriceps and/or forearm flexors. CK varied from 57-2939 IU/L. EMG was myopathic in 22, mixed in 2, and neuropathic in 3. Endomysial inflammation was seen in 23 (85.19%) and rimmed vacuoles in 24 (88.89%). Amyloid was demonstrated in only 5 (18.52%) and ubiquitin in 2 biopsies. Mitochondrial abnormalities were seen in 92.59% biopsies. CONCLUSIONS: Application of the ENMC IBM research diagnostic criteria allowed diagnosis of clinically-defined and probable IBM in the absence of all pathology criteria. Rimmed vacuoles in 88.89% of biopsies indicate presentation at a late stage. Use of ancillary techniques can improve diagnostic yield.

Tissue microarray based immunohistochemical study of TLE1 in synovial sarcoma and its histologic mimics.

BACKGROUND AND AIMS: Molecular analysis is gold standard for diagnosis of synovial sarcoma (SS) but use of these ancillary techniques is limited by many practical issues like cost and limited resources. Several studies analyzed TLE1 as a diagnostic immunohistochemical marker for synovial sarcoma and few studies disagreed. The objective of the study was to evaluate immunohistochemical expression of TLE1 in synovial sarcoma and its histological mimics. METHODS: The study included a total of 63 cases; of which 28 were synovial sarcomas (SS) and 35 its histologic mimics. A tissue microarray was constructed from these cases and subjected to TLE immunostaining. Nuclear immunoreactivity of TLE1 was graded as 0, 1+, 2+ and 3+ based on intensity and percentage of cells. RESULTS: All SS except one (27/28; 96.4%) were positive for TLE 1. These included 18 of monophasic spindle cell type (94.7%), 5 biphasic type (100%), followed by two each (100%) of poorly differentiated and calcifying type of SS. Of the other tumours 2 GISTs (50%), 2 haemangiopericytoma (66.7%), 2 schwannomas (50%) and one mesenchymal chondrosarcoma (33.3%) were positive for TLE1. CONCLUSION: TLE 1 is a highly sensitive marker with reasonable specificity for synovial sarcoma. Awareness of TLE1 expression in other tumours, is important to avoid misdiagnosis.

Thymoma diagnosis and categorization in the current scenario: Morphological analysis based on interobserver variability.

BACKGROUND: Thymomas are not so common tumors that are encountered in day-to-day pathology reporting. The WHO system was proposed in 2015. Although, through its detailed reporting, the WHO elaborates all subtypes and morphological clinches to diagnosis, it was important to ascertain its reproducibility in our day-to-day reporting. AIMS: The aims of the study were (1) to study the interobserver agreement, concordance rates, and variability in the classification of a large number of thymomas received in our department as per the WHO 2015, (2) to correlate the WHO subtype with Masaoka-Koga stage, and (3) to study the variations in demography of thymomas in Indian patients as compared to those reported in the literature. SETTING AND DESIGN: This retrospective study was done at a tertiary care teaching hospital with huge surgical oncology patient load, also pertaining to the cardiothoracic surgeries. It is predominantly an interobserver agreement design to study the reproducibility of the WHO 2015 classification on thymic epithelial tumors. METHODS: Four pathologists have independently reviewed histopathology slides of 65 cases of thymomas and classified them into predefined categories. Kappa statistics was applied to the observations. RESULTS: There was a substantial interobserver agreement in overall classification of thymomas with a Cohen's kappa score of 0.66. A better score was achieved for the classification of Group B thymomas. The WHO subtypes correlate well with the Masaoka-Koga staging system, and this finding is statistically significant. This article also presents the clinical details of a large number of thymoma cases. CONCLUSION: The new WHO classification has good reproducibility among pathologists in thymoma reporting.

Anti-glomerular basement membrane disease: A clinicomorphological study of 16 cases.

INTRODUCTION: Antiglomerular basement membrane disease manifests as rapidly progressive glomerulonephritis and alveolar hemorrhage. It encompasses 10-15% of crescentic glomerulonephritis and is associated with poor outcome. In this study, we have elaborated on the clinical details, morphological features, and outcome of anti-GBM glomerulonephritis. MATERIALS AND METHODS: All the consecutive biopsy-proven cases of anti-GBM glomerulonephritis over a period of 4½ years were analyzed, retrospectively. RESULTS: Sixteen cases were diagnosed as anti-GBM glomerulonephritis during the study period. Twelve patients presented with rapidly progressive renal failure of which four patients required hemodialysis at the time of presentation. Goodpasture's syndrome was noted in two patients. Thirteen cases were positive for circulating anti-GBM antibodies and two patients showed double positivity for both anti-GBM antibodies and ANCA. Fifteen biopsies revealed crescentic glomerulonephritis with linear deposition of IgG along the glomerular basement membrane in all the 16 cases. CONCLUSION: Renal biopsy analysis is important in the diagnosis of Anti GBM nephritis. Morphology is an important predictor of disease progression.

Homozygous R627W mutations in POLG cause mitochondrial DNA depletion leading to encephalopathy, seizures and stroke-like episodes.

Mutations in the mitochondrial DNA maintenance gene POLG (DNA Polymerase Gamma, Catalytic Subunit), encoding mitochondrial DNA polymerase gamma (pol γ), are associated with an extremely broad phenotypic spectrum. We identified homozygous POLG c.1879C>T; p.R627W mutations in two siblings from a consanguineous South Asian family following targeted resequencing of 75 nuclear-encoded mitochondrial genes. Both patients presented with encephalopathy, seizures and stroke-like episodes, and mitochondrial DNA depletion was confirmed in the proband's muscle tissue. Subsequent Sanger sequencing of POLG in a further 275 unrelated probands with genetically unconfirmed mitochondrial disease revealed a third unrelated proband with a similar phenotype harboring homozygous c.1879C>T; p.R627W mutations and a fourth patient, with a milder clinical disorder, harboring compound heterozygous POLG c.1879C>T; p.R627W and c.2341G>A; p.A781T mutations. Given endogamous practices in the Indian subcontinent, homozygous POLG c.1879C>T; p.R627W mutations should be excluded in South Asian patients presenting with encephalopathy, seizures and stroke-like episodes.

Molecular and Histopathological Characterization of Patients Presenting with the Duchenne Muscular Dystrophy Phenotype in a Tertiary Care Center in Southern India.

OBJECTIVE: To study the histopathological characteristics and mutation spectrum of patients presenting with the Duchenne muscular dystrophy (DMD) phenotype. METHODS: This was a descriptive study conducted over a period of 8 years. Multiplex ligation-dependent probe amplification (MLPA) was done in patients presenting with the DMD phenotype. If MLPA was negative, patients were offered muscle biopsy for histopathological studies and/or next generation sequencing (NGS) based multigene panel testing for muscular dystrophies. RESULTS: Of the 510 patients included, mutation in the DMD gene was detected by MLPA in 372 (72.9%), of whom 342 (67.1%) had exonic deletions and 30 (5.9%) had exonic duplications. Exons 45-55 were most commonly involved in large deletions and exons 1-10 were the commonest exons involved in duplications. In the MLPA-negative cohort, 27 proceeded for muscle biopsy. NGS was done in 14 patients, 10 of whom had pathogenic mutations in the DMD gene, 3 were non dystrophinopathies and no pathogenic variant could be identified in one patient. CONCLUSIONS: For patients presenting with the DMD phenotype, MLPA of the DMD gene has a high diagnostic rate of about 73%, and non-dystrophinopathies may constitute a small but significant proportion.