Revisiting the Utility of Histopathological Examination of Biopsy: A Necessity in Microbiology

Concordance of diagnostic modalities in atypical skin and soft tissue infections in hospitalized patients

Skin and soft tissue infections (SSTIs) have high rates of morbidity and mortality worldwide but lack reliable standards for diagnostic workup. As a result, atypical infections, more prevalent among immunocompromised patients, can be missed due to deviance from classic features only to be revealed later through inconsistently performed ancillary studies. Our objectives included to evaluate the sensitivities of clinical impression, histopathology, tissue culture, and molecular and non-molecular ancillary tests in diagnosing inpatient SSTIs, as well as to qualitatively discuss the unusual features making a subset of infections "atypical." To do so, we retrospectively reviewed the histopathologic reports and charts of inpatient dermatologic consults at a single tertiary care institution over a 3-year period. We identified a total of 111 cases of SSTIs evaluated by the inpatient dermatology consultation service with concurrent skin or soft tissue biopsy, with 32.4% representing atypical infections. Among these, clinical impression suggested infection in 9(25.0%), routine histopathology in 21(58.3%), specialized stains for microorganisms in 22(68.8%), and tissue culture in 15(68.2%). Due to incomplete picture that each modality by itself creates, we conclude that clinicians and pathologists should carry a low threshold for including SSTIs in their differential diagnoses and should evaluate with skin biopsy, special stains for microorganisms, and ancillary studies, particularly in critically ill individuals who necessitate timely diagnoses.

Rhino-Orbito-Cerebral Mucormycosis: An Audit

This study aims at identifying the predisposing factors, clinical and radiological features that dictated the treatment outcome of Rhino-orbito-cerebral mucormycosis (ROCM). This is a retrospective observational study. Medical records of 39 patients with ROCM proven by fungal smear or histopathology (HPE), admitted in Sri Ramachandra Institute of Higher Education and Research from Jan 2015 to Dec 2019 were reviewed and audited. The mean age of the patients was 52.6 years and they were predominantly men (76.9%). There is a statistically significant association between uncontrolled diabetes and increasing severity of the disease in this study and an important cause of mortality. Fungal smear and HPE plays a crucial role in diagnosis. Radiological evaluation helps in identifying the extent of spread and in this study 31% of patients had intraorbital and 20% had intracranial extension. In-hospital mortality was 13%. Our results showed better outcome when combined medical and surgical intervention was undertaken. Rhino-orbito-cerebral Mucormycosis is a rapidly spreading invasive fungal infection with significant mortality and morbidity. Early diagnosis and proactive surgical and medical intervention is crucial for better outcome. Hence the clinician should be highly alert to certain subtle clinical signs and radiological features in a diabetic patients for improving the treatment outcomes and avoiding potentially fatal complications.

Characteristics of Invasive Pulmonary Fungal Diseases Diagnosed by Pathological Examination

Objective

To explore the characteristics of invasive pulmonary fungal disease and the spectrum of pathogens causing invasive pulmonary fungal disease diagnosed by pathological examination using fungal stains.

Methods

Patients with an invasive pulmonary fungal disease diagnosed by histopathological analysis through the use of fungal stains (including Grocott's methenamine silver and periodic acid-Schiff stains) were included in this study. The clinical records, radiological reports, pathology, and fungal culture results were reviewed.

Results

Forty-eight invasive pulmonary fungal disease patients diagnosed by histopathological analysis in the Tianjin Haihe Hospital (including 8 cases obtained by pulmonary resection, 35 cases by fiberoptic bronchoscopic biopsy, and 5 cases by percutaneous lung biopsy) were included. There were 24 male and 24 female patients, aged 21–80 years (53 ± 13 years). There were 37 cases of pulmonary aspergillosis, 4 cases of pulmonary cryptococcosis, 2 cases of pulmonary mucormycosis, and 5 in which pathogens were not determined due to limited tissue availability. Among 48 cases, 32 specimens were submitted to fungal culture. No fungus was detected in culture, although 26 cases of fungus infections were diagnosed by histopathological analysis. Only 3 cases were consistent between histopathological and culture results. In 3 cases, the pathogen was identified as Aspergillus spp. by the histopathological analysis, while the contrasting fungal culture results identified Candida albicans.

Conclusion

Candida albicans pneumonia was rare, while aspergillosis was common in invasive pulmonary fungal disease diagnosed by histopathological analysis. The majority of patients with an invasive pulmonary fungal disease were culture-negative. Although culture can clarify the fungal pathogen species, it has low sensitivity. Pathological examination with fungal stains has its advantages in diagnosing fungal disease; therefore, more attention should be paid to the role of pathological examination in the diagnosis of fungal disease.