ABSTRACT
Background Mucormycosis, attributed to a group of molds known as mucormycosis, is a rare yet life-threatening fungal infection often colloquially referred to as black fungus. While its incidence notably surged during the second wave of COVID-19 infections in India, it's essential to recognize that mucormycosis was a significant concern even before the advent of the pandemic. Understanding the prevalence and characteristics of this infection in the pre-COVID era provides a crucial context for evaluating its impact and dynamics during the pandemic. Multiple diagnostic methods, such as potassium hydroxide (KOH) mount, culture, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), and histopathological examination (HPE), are available for identifying this lethal infection. The primary objective of this study is to ascertain the sensitivity of various diagnostic methods for mucormycosis and to analyze the comparative effectiveness of microbiological versus histopathological diagnoses. Methods We conducted a retrospective observational study spanning six months, from May 2021 to October 2021, encompassing all mucormycosis cases meeting the inclusion criteria and diagnosed via histopathological examination (HPE) in the departments of pathology and microbiology. Microbiological tests were performed prior to the histopathological examinations. Sensitivity was assessed through statistical analysis, and the relationship between microbiological and histopathological diagnoses was evaluated using the chi-square test. Results Biopsy samples of 77 patients were collected, comprising 56 male and 21 female patients. Regarding age distribution, most patients fell within the 41-60 age bracket, while the smallest proportion was over 60 years old. The sensitivity and specificity of histopathological diagnosis, confirmed with periodic acid-Schiff (PAS) and Grocott-Gomori's methenamine silver (GMS) staining, both recorded a flawless 100%. KOH mount sensitivity stood at 88.3%, while fungal culture and MALDI-TOF exhibited sensitivities of 75.3%. Histopathological analysis revealed that 17% of cases displayed minimal fungal hyphae alongside necrotic tissue, whereas 58% exhibited abundant fungal hyphae accompanied by inflammatory cells. Additionally, absolute neutrophilia was observed in 55% of cases. Conclusions In our study, histopathology and KOH mount emerged as not only compassionate but also cost-effective diagnostic tools for identifying mucormycosis. The economic aspect of these diagnostic methods is highlighted in the results section to provide a comprehensive understanding of their cost-effectiveness. Additionally, we utilized MALDI-TOF MS as a straightforward, economically viable, and expeditious method specifically for confirming the fungal subtype in mucormycosis cases. The rationale behind choosing either MALDI-TOF MS or KOH for the diagnosis is elucidated, contributing to a clearer interpretation of our diagnostic approach. Furthermore, our findings indicate that absolute neutrophilia consistently manifests in 55% of mucormycosis cases.
ABSTRACT
Round cell tumors are a group of malignant tumors which shows overlapping microscopic features of small round monotonous cells with hyper-chromatic nucleus. It mostly occurs in children, adolescent, and young adults. The ancillary technique to confirm the differential diagnosis of round cells sarcoma is immuno-histo chemistry (IHC). Therefore, it is of interest to document the diversity of small round cell sarcoma in soft tissues around bones among Indian patients using IHC. A total of 334 cases among Indians were studied. Among them 160 cases were Non-Hodgkin's Lymphoma, 82 cases are poorly differentiated carcinoma and 92 cases of round cell sarcoma. Out of 92 cases, there were (40%) 27 cases of Wilms tumour, with the highest incidence. The highest incidence was observed in 0-14 years of age group with highest incidence in males. The distribution and diverse histology of different small round cell sarcoma offers challenge in the diagnosis by histopathology. Most frequent round cell tumour is Wilms tumour, followed by Rhabdomyosarcoma. Data shows the role of IHC in classifying soft tissue sarcoma but some time result of IHC remains inconclusive, where cytogenetic is important.
