Kikuchi-Fujimoto disease, a rare benign disease with atypical histomorphology: more than meets the eye.

Kikuchi-Fujimoto disease (KFD) is a benign self-limiting condition primarily affecting young females. It usually presents with fever and cervical lymphadenopathy of unknown aetiology with a preponderance of the Asian population. Histopathology is critical in making an accurate diagnosis. While the typical microscopic features include paracortical necrosis with debris, histiocytosis with immunoblasts, and absent neutrophils, rarely, KFD can show atypical features like marked immunoblastic proliferation mimicking lymphoma, demonstrate vasculitis mimicking lupus erythematosus, etc. The diagnosis is extremely challenging if such features occur in cases with generalised lymphadenopathy, which is infrequent in KFD. The study aims to describe the morphological, clinical, and immunohistochemical features of KFD and determine the frequency of the atypical features. We also analysed the subtle histological and immunohistochemical features that aid in the diagnosis of atypical cases. Cases reported as KFD over a period of 6 years were retrieved from the archives of histopathology. The morphological features were categorised as typical and atypical. In the atypical cases, the features that aided in the correct diagnosis of KFD were analysed. Out of the 42 cases evaluated, 23.9% (n=10) had generalised lymphadenopathy; 57.2% (n=24) were women with a median age of 25 years. Leukopenia was observed in 42% (n=13) of patients. Typical features were present in 76.2% (n=32) cases and 23.8% (n=10) presented with atypical features. Eight cases were antinuclear antibody-positive. Atypical features included five (50%) cases with vasculitis and panniculitis, and three (30%) cases with large, atypical cells for which immunohistochemistry (IHC) was performed. In two of these cases, the patent sinuses, absence of neutrophils, and IHC with CD68 aided the diagnosis. There is an overlap of clinical and histopathological features between KFD and malignant lymphomas and systemic lupus erythematosus. Given the fact that the atypical features (23.8%) are not rare occurrences in KFD, correlations with clinical findings and ancillary studies are essential to avoid misdiagnosis and inadvertent therapy.

Role of histopathology in severity assessments of post-COVID-19 rhino-orbital cerebral mucormycosis - A case-control study.

BACKGROUND: There was an upsurge in rhino-orbital-cerebral mucormycosis (ROCM) during the second wave of the COVID-19 pandemic in India. Histopathological examination of the biopsies witnessed greater tissue invasion in these cases. The present study aimed to evaluate the histopathological scoring system in the severity assessment and to compare the scores between ROCM that required orbital exenteration (cases) and those that were treated conservatively (controls). MATERIAL AND METHODS: A retrospective study was conducted to analyze the histopathological features using a scoring system in patients diagnosed with mucormycosis on sino nasal biopsies. The scoring was based on the following parameters: the extent of necrosis (score 1 <50% and score 2 >50%), degree of angioinvasion (score 1 <3 vessels in 10 fields and score 2 > 3 vessels in 10 fields), degree of inflammation (mild, moderate or severe), and fungal load(score 1 to 4), based on which three grades (I to III) were given. The scores were compared between the case group and the control group. The data obtained were analyzed statistically. RESULTS: The study included 40 controls and 10 cases. The median age of patients in the control group was 52 with 82.5%males (n = 43) and 17.5 % females (n = 7) while in the case group, the median age was 51 years, and all were males. The predominant inflammatory response was of mixed suppurative type (70 %, n = 28). The degree of necrosis was scored 2 in 57.5 % (n = 23) of controls and 70 %(n = 7) in the case group. All the samples in the case group showed scores of 2 for angioinvasion and scores of 3 and 4 for fungal load. There was a statistically significant difference in the degree of necrosis, angioinvasion, the severity of neutrophilic infiltrates, and fungal load between the cases and controls (p-value <0.05). CONCLUSION: The present study analyses the predictive role of histopathology in invasive mucormycosis. Higher fungal load, degree of angioinvasion, and the absence of granulomas are associated with advanced disease in sinonasal mucormycosis. The study findings recommend incorporating the histopathological scoring criteria in evaluating patients with sinonasal mucormycosis.

The Application of the Proposed Sydney System for Reporting Lymph Node Cytopathology: A Five-Year Experience of an Academic Institution in South India.

INTRODUCTION: Fine needle aspiration biopsy (FNAB) is a routinely used investigation in the evaluation of lymph node pathologies. However, there exists a lack of uniformity in cytopathology reporting owing to the nonavailability of standard guidelines. Recently, a novel system for reporting lymph node cytopathology has been proposed. The present study aimed to analyze the utility of the proposed system in cytopathology reporting in our institution. MATERIALS: FNABs of lymph nodes performed over a period of 5 years were categorized as per the proposed Sydney system. The diagnoses on cytopathology were correlated with histopathologic diagnoses to assess the diagnostic accuracy. The rate of malignancy (ROM) for each category was calculated. RESULTS: A total of 747 lymph node FNABs were included in the study. Histopathology was available in 262 cases. ROM in categories I-V was 26.3%, 7.2%, 76.9%, 82.3%, and 100.0%, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of FNAB when considering category L3 to represent benign cytopathology were 84.2%, 97.5%, 97.1%, and 86.2%, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of FNAB when considering category L3 to represent malignant cytopathology were 92.56%, 95.08%, 94.9%, and 92.8%, respectively. CONCLUSION: The study substantiates the usefulness of the proposed Sydney system in lymph node cytopathology in enhancing better communication between clinicians and cytopathologists. The use of ancillary techniques like immunocytochemistry and flow cytometry will aid in arriving at a more precise diagnosis.

Utility of the pattern-based approach using BIOCHIP-indirect immunofluorescence in the evaluation of subepidermal bullous disorders.

BACKGROUND: Subepidermal bullous disorders (SEBD) are a heterogeneous group of vesiculobullous diseases because of antibody-mediated destruction of proteins of the dermo-epidermal junction. Direct immunofluorescence (DIF) is the gold standard for diagnosis. BIOCHIP-indirect immunofluorescence (IIF) is a novel serological test that combines multiple target antigens in a single field. The present study aimed to evaluate the utility of the pattern-based approach in BIOCHIP-IIF for the diagnosis of SEBD. METHODS: Seventy cases of BIOCHIP-IIF that showed clinical, histopathological, and/or DIF features favoring SEBD were included in the study. The interpretation in the BIOCHIP was categorized into one of the following patterns. Pattern I: basement membrane zone (BMZ) staining in monkey esophagus (ME), primate salt-split skin (SSS)-roof staining, BP180+ and/or BP230+; Pattern II: roof staining in SSS, BP180- and BP230- with or without BMZ staining in ME; Pattern III: floor staining in SSS, BP180- and BP230-; and pattern IV: negative in SSS and other substrates. The findings were correlated with histopathology and/or DIF. RESULTS: Fifty (71.5%) cases showed pattern I or the typical bullous pemphigoid (BP) pattern. Eight (11.4%) cases showed pattern II. Patterns III and IV were observed in seven (10%) and five (7.1%) cases, respectively. BP was the most common diagnosis in patterns I and II, while anti-p200 pemphigoid was most common in pattern III, as confirmed by immunoblotting. The sensitivity of pattern I in the diagnosis of BP was 96%. CONCLUSION: BIOCHIP-IIF showed a good correlation with DIF and histopathology in the diagnosis of SEBD. This can be used as a first-line investigation in case of bullous disorders.

The role of the IAC Yokohama System for Reporting Breast Fine Needle Aspiration Biopsy and the ACR Breast Imaging-Reporting and Data System in the evaluation of breast lesions.

BACKGROUND: Stratification of breast lesions for appropriate management is achieved through an integration of clinical examination, imaging, and fine needle aspiration biopsy (FNAB). The current study aimed to evaluate the combined effectiveness of the widely used Breast Imaging-Reporting and Data System (BI-RADS) with the recently proposed International Academy of Cytology (IAC) Yokohama System for Reporting Breast Fine Needle Aspiration Biopsy Cytopathology. METHODS: A retrospective analysis was done on all breast FNABs from 2016 through 2020. The cases were categorised according to the IAC Yokohama System. Histopathological correlation of the BI-RADS and IAC Yokohama System was performed. The rate of malignancy (ROM) for each category of the BI-RADS and IAC Yokohama System was calculated. RESULTS: The ROM values for categories I to V were 38%, 0.6%, 21.9%, 100%, and 97%, respectively. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of FNAB with category III assumed as malignant were 98.9%, 85%, 76.1%, 99.3%, and 89.5%, respectively. With category III assumed as benign, these indices were 90.8%, 98.9%, 97.5%, 95.7%, and 96.2%, respectively. The sensitivity, specificity, PPV, NPV and accuracy of BI-RADS were 91.5%, 81.9%, 72%, 95%, and 85.1%, respectively. CONCLUSIONS: FNAB is still an indispensable test in the evaluation of breast lesions. The utilisation of the IAC Yokohama reporting system for breast cytology in conjunction with ACR BI-RADS aids in better stratification of lesions.

The Value of Duodenal Biopsies in the Evaluation of Megaloblastic Anemia.

Introduction Megaloblastic anemia is one of the common causes of anemia in India. Duodenal biopsies are routinely performed in the investigation of megaloblastic anemia. The present study was undertaken to analyze the value of duodenal biopsy in megaloblastic anemia and to correlate endoscopic findings with biopsy. As a secondary aim, the study has also analyzed the hematological profile and vitamin B 12 and folate status of these patients. Materials and Methods All the cases of megaloblastic anemia with bone marrow studies diagnosed at PSG Institute of Medical Sciences and Research during the two year period from January 2016 to December 2017 were retrieved. Clinical and laboratory findings (serum vitamin B 12 and folate levels) and endoscopic findings were retrieved from hospital records of the patients. Duodenal biopsies of these patients reported in the histopathology department were retrieved and reviewed. Statistical analysis was done using SPSS software 20.0. Results There were 93 cases of megaloblastic anemia diagnosed on bone marrow biopsies. Tropical sprue was diagnosed in 49.5% of cases, followed by intraepithelial lymphocytosis (17.2%), peptic duodenitis (17.2%), and no significant pathology in 16% of cases. Pancytopenia was present in 54.8% of cases. Isolated vitamin B 12 deficiency including low levels was present in 48.38% and folate deficiency was seen in 4.3% cases; 34.48% cases had both vitamin B 12 and folate deficiency. Conclusion The incidence of tropical sprue in megaloblastic anemia is 49.5% in the study. Duodenal biopsy is valuable in the work up of megaloblastic anemia, irrespective of the endoscopic changes in identifying the etiology.

Pathologist's role in identifying cardiac defects-a fetal autopsy series.

AIMS: Major cardiac abnormalities can lead to miscarriages and is also an important indication of medical termination of pregnancy. The present study aims: (1) To determine the spectrum of cardiac anomalies in fetal autopsies, (2) To correlate the autopsy findings with prenatal imaging studies. METHODS: Fetal autopsies with cardiac anomalies were retrospectively analyzed over a period of five years. Autopsy diagnoses were correlated with prenatal ultrasound and echocardiogram findings. RESULTS: Of the 177 fetal autopsies, 40 (22.5%) cases with cardiac defects were identified. Among these cases, 11 (27.5%) showed only cardiac defects and associated extracardiac malformations were seen in 29 cases (72.5%). Septal defects (45%) were the most frequent cardiac defect followed by left ventricular outflow tract obstruction. Agreement with prenatal imaging and autopsy findings was seen in 65% of cases. There was 100% concordance between autopsy and echocardiogram wherever available. CONCLUSION: Cardiac malformation forms a significant subset of fetal congenital anomalies. Meticulous examination and following sequential segmental analysis during autopsy are essential in identifying complex cardiac and additional extra cardiac defects in the fetuses. Fetal autopsy plays a vital role in confirming and/or refuting the imaging findings and could be the steppingstone in understanding the pathogenesis of cardiac abnormalities.