A Case Report of a Mysterious Mycetoma.

Mycetoma, a chronic subcutaneous infection caused by bacterial or fungal species from soil and water, presents a diagnostic challenge due to its rarity and diverse clinical manifestations. Predominantly affecting male workers in endemic regions, mycetoma typically manifests as painless swelling evolving into purulent lesions with draining sinuses in the extremities. Although historically uncommon in regions like North America, rising immigration and international travel have led to an increased prevalence, necessitating heightened clinical suspicion. Early diagnosis is crucial to prevent severe complications such as limb loss and septicemia. This case report details the diagnosis and management of chronic actinomycetoma due to Nocardia spp. in a Guatemalan immigrant landscaper and emphasizes the importance of comprehensive understanding and timely intervention in mycetoma cases.

Dynamic pathology and pathogen distribution of the yeast Metschnikowia bicuspidata in the Chinese mitten crab (Eriocheir sinensis).

In this study, the "milky disease" model of Eriocheir sinhensis was constructed via intramuscular injection with the pathogenic yeast Metschnikowia bicuspidata. The dynamic pathological changes of E. sinensis after injection were elucidated with two staining methods (haemotoxylin-eosin and alcian blue periodic acid-Schiff) and fluorescence in situ hybridization technology. Anatomical observation revealed three stages of the "milky disease": no clinical signs (1-4 days after infection), the appearance of signs of disease (5-7 days), and significant liquefaction (10 days). Histological observation also revealed three stages of the disease: yeast diffusion (1-2 days after infection), yeast slow development (3-4 days), and yeast rapid proliferation (5 days). And FISH technique was suitable for the early detection of infection with M. bicuspidata in E. sinensis. We found that M. bicuspidata spread to the whole body of the crab through the haemolymph and developed into fungal septicaemia. These results elucidate the systemic pathological characteristics of "milky disease" in E. sinensis and suggest the pathogenic mechanism of M. bicuspidata.

Mucormycosis in Post Novel Corona Virus Patients: An Institutional Experience.

Mucormycosis is an emerging angioinvasive fungal infection caused by ubiquitous saprophytic filamentous fungus that belongs to the class Zygomycosis. Mucormycosis or black fungus infections in patients with recent COVID-19 infections has given rise to a new epidemic during the second wave of this current COVID-19 pandemic in India. Steroid misuse, poor glycemic control, use of industrial grade oxygen, improper humidification and specific variants strains have resulted in profound immunosuppression and are attributed for the high incidence of COVID associated Mucormycosis (CAM) in India. The aims of the present study were to assess the age and gender specific incidence of CAM, the utility of special stains (PAS and GMS) for diagnosing mucormycosis (false negatives and sensitivity). In the present study emphasis was laid on identifying if there exists a correlation between host response, angioinvasion and bone invasion with mortality. The Present study is a retrospective, cross sectional analytical study taken up in the Department of Pathology, Guntur Medical College for a period of 2 months between 1st of May 2021 to 30th of June 2021. Results were tabulated in Microsoft excel 2016 and SPSS software version 14 was used for calculation of odds ratio and for performing multivariate analysis. All samples were routinely fixed using 10% buffered formalin, processed and sectioned. All the sections were stained with Haematoxylin and Eosin and also special stains for fungus like periodic acid Schiff (PAS) and Gomori Methenamine silver (GMS) were used wherever required. CAM is a serious complication after recovery from COVID-19 infection due to its high morbidity and mortality (13.7% in this series). CAM epidemiology and presentation is mostly similar to non-COVID mucormycosis seen in pre-COVID era.

CelLock TM: an innovative standardized cell-block preparation procedure.

The CelLock™ procedure kit is used to collect and prepare cellular specimens such as fine needle aspirates (FNA), cytology specimens, cultured cells, small tissue biopsies, and samples with scant tissue fragments or cells into a paraffin cell-block. This cell-block can be used for subsequent microtomy and staining using hematoxylin and eosin (H&E), special stains, immunohistochemistry (IHC), and applicable molecular techniques such as in situ hybridization (ISH). CelLock is a standardized method that provides optimal receipt, preservation, preparation, and processing of cell-blocks which, contain virtually all of the submitted specimens and are able to be embedded and sectioned in a reproducible fashion. The specimen contained within the cell-block is preserved such that all the cellular protein and genetic information is available for histological and ancillary testing.

Highlights of infectious agents in tissue.

The evolution of the diagnosis of infectious diseases began with the observation of the morphological characteristics of organisms such as ascaris and whipworms, followed by the use of the microscope and haematoxylin and eosin stains, which allowed recognition of microscopic characteristics undetectable with the naked eye, such as the viral cytopathic changes of herpes and the presence of fungi. Patterns of acute and chronic granulomatous inflammation were also observed; these were not specific to the exact aetiology of the disease, which led to the introduction of special methenamine stains for fungi and Ziehl-Neelsen for fungi and mycobacteria. Later, the use of immunohistochemistry was introduced, which acknowledged the use of antibodies to classify microorganisms and detect cases that were either difficult to interpret or in the midst of severe inflammatory processes. Currently, the use of molecular biology has made it possible to reach diagnoses that would have been very difficult to obtain through traditional methods; these techniques show key specific characteristics and facilitate the diagnosis of various infectious pathologies. These new techniques are based on the detection of antigens and nucleic acids of microorganisms, an important advance in the diagnosis of infectious diseases.

Use of laser-scanning confocal microscopy in the detection of diagenesis in bone.

This research demonstrates the value of laser scanning confocal microscopy (LSCM) as a research tool in osteological studies, and diagenetic studies in particular. LSCM combines properties of light and scanning electron microscopy using laser light to excite fluorophores throughout the z-axis, developing a 3-D image. Using differential staining and selecting for specific wavelengths of light, one can image targeted materials. This research is divided into two parts: visualizing bone structures such as proteins and their decompositional products and visualizing diagenesis. Part one of this study utilized pig bones as a means of testing the overall ability of LSCM to fluoresce bone. Twenty-three samples were imaged, including 13 samples from a decompositional study conducted 5 years previous, and 10 "fresh" samples collected from a commercial butcher. This part of the study determined that protein and organic components of the bone could be fluoresced and diagenetic alteration could be imaged. The second part of the study used human samples as a means of imaging and mapping diagenetic alterations. The second part of the study used 13 samples, including 4 clinical, 7 ancient, and 2 modern controls. The pig study used Basic Fuchsin and SlowFade Gold stains, while the human study used toluidine blue. Images were also taken with unstained elements. The results of the non-human study found that a fresh bone fluoresced differently than that of a 5-year subset, while the results of the human study confirmed these findings and determined that the bone diagenesis can be mapped using LSCM.

Update in Infectious Disease Diagnosis in Anatomic Pathology.

Anatomic pathology is an important resource for detection and exclusion of infectious diseases in tissue specimens. Detection of a microorganism (i.e. bacteria, fungi, parasite) in tissue sections is frequently the beginning of a work-up and occasionally sufficient for definitive microbiologic identification. Close correlation with cultures and ancillary testing in the microbiology laboratory is of paramount importance in arriving at a diagnosis and identify with certitude causative pathogen(s). This review will discuss the adequacy and limitations of histopathology in the diagnosis of infectious diseases, describe potential pitfalls, and discuss the appropriate use of molecular diagnostics in formalin-fixed, paraffin embedded tissues.

A review on histotechnology practices in COVID-19 pathology investigations.

COVID-19 disease in humans, caused by the novel SARS-CoV-2 virus, was first reported in the city of Wuhan, China in December 2019. This disease has quickly developed into a global pandemic, resulting in over 350,000 deaths worldwide and over 5 million confirmed infections in a matter of 6 months. Although the genome of this novel viral RNA was sequenced quickly and testing kits were manufactured to assist in combatting COVID-19, the diagnosis and treatment will remain relatively unsuccessful until the pathology of this disease is fully understood. Histotechnology plays an important role in understanding the pathology of many diseases, including COVID-19. The first postmortem biopsy of a COVID-19 patient was collected on 27 January 2020, and the pathology finding was published in mid-February 2020. Since then, more studies have been published in scientific literatures as the global outbreak continues. This mini-review summarizes the published articles in which histotechnology aspects were utilized with the intent to understand the pathology of COVID-19. In addition, it is anticipated there will be more molecular and immunohistochemical studies to further understand the mechanism of the disease in the near future.

Comparison between organismal staining on histology and tissue culture in the diagnosis of cutaneous infection: A retrospective study.

BACKGROUND: In instances of suspected cutaneous infection, the standard of care includes obtaining skin biopsy specimens for histology and tissue culture. Few studies have compared the clinical utility of each test. OBJECTIVE: To assess the concordance of results between tissue culture and histology, as well as the clinicopathologic features that may influence the diagnostic yield of each test. METHODS: A retrospective review of all patients who underwent skin biopsy for histology and tissue culture at New York University from 2013 through 2018. RESULTS: Of 179 patients, 10% had positive concordance, 21% had positive tissue culture only, and 7% had positive histology only. We calculated a kappa correlation coefficient of 0.25 between histology and tissue culture (reference, 0.21-0.39 indicates minimal agreement). Histology exhibited higher sensitivity in detecting fungi, whereas tissue culture was more sensitive in identifying Gram-negative bacteria. Antimicrobial use before biopsy led to significantly fewer positive cultures (37.5% vs 71%; P = .023) in patients ultimately diagnosed with infection. LIMITATIONS: This study was conducted at a single institution, thereby restricting its broad applicability. The lack of a validated criterion standard to diagnose infection also limits interpretation of the results. CONCLUSION: Tissue culture and histopathology often yield discordant results. Dermatologists should recognize specific limitations, yet high clinical utility in special circumstances, of tests when approaching cases of suspected infection.

Educational Case: Vitiligo.

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040.1.

Collagen fibers in oral submucous fibrosis - A polarizing microscopy study using two special stains.

BACKGROUND: Oral submucous fibrosis (OSMF), a well-recognized oral potentially malignant disorder, results due to increased collagen production and reduced collagen degradation. AIMS AND OBJECTIVES: To qualitatively compare the staining properties of collagen in OSMF using two special stains based on their birefringent property using polarizing microscopy. The study also assessed the distribution and orientation of collagen fibers in different grades of OSMF. MATERIALS AND METHODS: A total of 73 subjects with different clinical and histopathological staging of OSMF comprised the study population. Histopathological examination was done using hematoxylin and eosin stain, Van Gieson and picrosirius red. Collagen fibers were analyzed for polarization colors, distribution, and orientation. RESULTS: Picrosirius red stained both thick and thin collagen fibers. Irrespective of the histopathological grades reddish orange and yellowish orange were the most predominant colors. Parallel arrangement of fibers was observed when stained with Van Gieson but picrosirius red stained sections showed a majority of parallel type I fibers with perpendicular type III fibers which increased with advancement in the histopathological grade. Yellowish orange and greenish yellow fibers were predominant in the lamina propria, while reddish orange fibers were predominant in the submucosa. CONCLUSION: Picrosirius red was found to be a better stain. Histopathological grading and polarization colors showed no association with each other. Collagen fibers were more thickly and tightly packed in the submucosa indicating that the process of fibrosis began there. The increase in perpendicular type III fibers with advancing histopathological grades suggested their role in fibrosis.

Primary Amyloidosis - In a Case with Normal Plasma Cell Counts.

Amyloidosis is a group of disease that is characterized by the deposition of extracellular abnormal proteinaceous material (amyloid), in various organs. Amyloidosis involving the liver is common and the radiological findings are often nonspecific. We present the case of a 40-year-old female who presented with abdominal pain. Ultrasound abdomen was reported as massive hepatomegaly with diffuse liver parenchymal disease. Bone marrow aspiration showed normomegaloblastic erythroid hyperplasia and plasma cells were within normal limits (5%). Also, amorphous, eosinophilic fragmented to smudgy material within the interstitium of cell trails was seen. Bone marrow biopsy and liver biopsy also showed similar kind of homogenous eosinophilic material. Both liver biopsy and bone marrow biopsy were subjected to special stains which confirmed the presence of amyloid. The patient did not have clinical or laboratory findings suggestive of any other organ involvement. Thus, we conclude that clinical and imaging presentations of amyloidosis are often nonspecific, hence biopsy is always required to confirm the diagnosis. Amyloid deposits on bone marrow aspiration are a rare occurrence and are often missed. It is an unusual sighting with very few studies mentioning its occurrence.

Aberrant staining with Grocott's methenamine silver: utility beyond fungal organisms.

INTRODUCTION: Historically, Grocott's methenamine silver (GMS) stain has been used in cytopathology to highlight Pneumocystis jiroveci and other fungal organisms. Several nonfungal organisms, however, can show distinct GMS staining patterns that are important to recognize. MATERIALS AND METHODS: We prospectively and retrospectively identified nonfungal pathogenic organisms on GMS-stained liquid-based and cytospin preparations of respiratory cytologic specimens. The organisms included parasitic worms, viruses, and assorted bacteria. Nine cases were identified, including two cases each of Strongyloides stercoralis, Cytomegalovirus, Mycobacterium tuberculosis, Nocardia species, as well as one case of anthrax-like Bacillus cereus. RESULTS: The nonfungal organisms had silver deposition in varying locations including the internal organs and/or cuticle of Strongyloides stercoralis larvae, the intranuclear inclusions of Cytomegalovirus infected cells, the surfaces of partially acid-fast Nocardia species and acid-fast Mycobacterium tuberculosis, and the cell walls and central endospores of Bacillus cereus. In 3 of the 9 cases, organisms were not clinically suspected. It was the aberrant GMS staining that pointed to the diagnosis and led to the performance of the definitive stain, culture, or other test. CONCLUSIONS: GMS is a chromic acid, sodium bisulfate stain that precipitates silver ions in fungal polysaccharide walls, producing the characteristic black stain on light microscopy. It is helpful to recognize aberrant GMS staining to avoid misdiagnosis of fungal elements. GMS stains several nonfungal human pathogens and may be a particularly useful diagnostic aid when the infectious condition is not clinically suspected or the number of organisms is sparse and otherwise difficult to visualize by routine staining methods.

Giant-cell fibroma: Understanding the nature of the melanin-laden cells.

Giant-cell fibroma is a localized, benign fibrous mucosal mass, which clinically mimics any other fibroepithelial growth, and its distinction from other lesions is on the basis of its peculiar histopathology. A case of giant-cell fibroma with stroma strewn with brown pigment-laden cells is presented herewith. Immunohistochemical staining aided with histochemical reaction to understand the origin of these cells was carried out. Various mechanisms that explain the presence of melanin granules in reactive lesions of giant-cell fibroma is discussed in the present report.

Diagnostic accuracy of Wright-Giemsa and rhodanine stain protocols for detection and semi-quantitative grading of copper in canine liver aspirates.

BACKGROUND: Canine hepatic copper content has been increasing. Recognition of canine copper-associated hepatopathies is becoming more common. OBJECTIVES: The purpose of the study was to assess the diagnostic performance of Wright-Giemsa (WG) and rhodanine staining for detection of increased canine hepatic copper following a proposed cytologic protocol for semi-quantitative evaluation of liver aspirates and the effect of previous WG staining. METHODS: Retrospectively, 40 canine hepatic WG-stained cytology cases were rhodanine stained. Diagnostic performance of WG staining for increased hepatic copper was evaluated. A rhodanine-stained cytologic copper grading system was developed. Prospectively, 67 canine liver samples with quantitative copper measurement, a WG-then rhodanine-stained slide, and a non-WG rhodanine-stained slide were used to assess the performance of the grading system and the effect of previous WG staining. RESULTS: Copper was not described in 40 retrospective cases on initial cytologic evaluation; 8/40 cases had increased copper content after rhodanine staining or quantitative copper assessment. Prior WG staining and destaining significantly affected the cytologic copper grade but not the diagnostic performance as measured by receiver-operating characteristic curve analysis. Quantitative copper concentration and previously WG-stained copper grade were moderately correlated (n = 67, ρ = .79 [.68-.87]). For detection of ≥ 600 ppm, dry weight (dw) copper, sensitivity was .75 and specificity was .97. For detection of ≥ 1500 ppm, dw copper, sensitivity was 1.0 and specificity was .97. CONCLUSIONS: Wright-Giemsa staining alone does not reliably detect hepatic copper. Grading of rhodanine-stained canine hepatic cytologic samples demonstrates acceptable diagnostic performance for detection of copper content.

Prospective identification of Helicobacter pylori in routine gastric biopsies without reflex ancillary stains is cost-efficient for our health care system.

Despite the recommendation of expert gastrointestinal pathologists, private and academic centers (including our own) have continued to use ancillary stains for identification of Helicobacter pylori. For a 1-month period, gastric biopsies were prospectively evaluated for H pylori using routine hematoxylin and eosin (H&E) and a reflex Diff-Quik stain. During this time, 379 gastric biopsies were collected on 326 patients. H pylori organisms were prospectively identified in 23 (7%) patients, all of whom had superficial dense lymphoplasmacytic inflammation expanding the lamina propria. An additional 2 patients with neutrophilic inflammation were found to have H pylori by immunohistochemical staining. One patient diagnosed as having normal gastric mucosa was retrospectively found to have inflammation with rare H pylori organisms originally overlooked on both H&E and Diff-Quik but later identified on immunostain (0.5%). No patients with chemical gastritis (16%) or chronic inflammation (27%) were found to have H pylori. During the study month, 9 immunostains for H pylori were performed in addition to the 379 Diff-Quik. After discontinuation of reflex Diff-Quik, approximately 20 immunostains are performed for H pylori each month, which decreases technical time spent for processing gastric biopsies and reduces cost to the health care system. In our population with a low prevalence of H pylori, reflex staining for organisms is not cost-effective. The organisms can be seen on routine H&E; when suspicious superficial or active inflammation is present without visible organisms, immunohistochemical stains will confirm presence or absence within a day. Discontinuation of up-front ancillary studies is cost-effective without compromising patient care.

Secondary Sea-Blue Histiocytosis in a Patient with Transfusion Dependent HbE-Beta Thalassaemia and Osteosarcoma.

Secondary sea-blue histiocytosis occurs more frequently than the primary form and occurs consequent to a wide range of metabolic and haematologic disorders including thalassaemia. We report an 18-year-old Chinese boy with transfusion-dependent HbE-beta thalassaemia who complained of pain and swelling at the left iliac crest region for 2 months duration. Physical examination revealed pallor with hepatosplenomegaly. Local examination revealed a huge swelling 12 cm × 12 cm in diameter, firm in consistency and tender. Histopathological examination of the mass revealed an osteosarcoma. His bone marrow aspirate showed numerous sea-blue histiocytes, the cytoplasm of which was closely packed with fine granules that stained blue with May-Grunwald-Giemsa. The nuclei were centrally located in some cells and displaced towards the periphery in other cells. There was no malignant cell infiltration in the marrow. The case is reported due to the co-incidental dual pathology in our patient (HbE-beta thalassaemia and osteosarcoma) and the unusual bone marrow finding of numerous sea-blue histiocytes.

The use of special stains at two dermatopathology laboratories in East Africa.

BACKGROUND: Histopathology is often essential to establish an accurate diagnosis. Pathology laboratories are scarce in most Sub-Saharan Africa where dermatopathology is a developing field. In resource-poor countries, most specimens are analyzed only after hematoxylin and eosin staining. The availability of special stains is very limited and restricted to only few centers. The aim of this study is to analyze the extent of dermatopathological cases which can be adequately diagnosed after hematoxylin and eosin alone. Secondly, to investigate which cases required further special stains. METHODS: All skin specimens submitted to two University Hospitals (Tanzania and Kenya) were included in this study. All specimens were first analyzed with hematoxylin and eosin and a diagnosis established when possible. All cases in which an accurate diagnosis after hematoxylin and eosin only was not possible, were registered and evaluated after further special stains. RESULTS: A total of 386 specimens were examined. A proper histopathologic diagnosis with hematoxylin and eosin alone was possible in 344 (89.1%) samples. In 45 (11.6%) cases, mostly skin infections, further special stains were necessary. CONCLUSION: A proper histopathologic diagnosis was possible after hematoxylin and eosin alone in almost 90% of the specimens submitted to the two laboratories in Sub-Saharan Africa.

Helicobacter infections with rare bacteria or minimal gastritis: Expecting the unexpected.

BACKGROUND: The routine use of special stains for detection of Helicobacter remains controversial. AIMS: To determine the frequency of histologically atypical Helicobacter infection. METHODS: All gastric biopsies received at a large pathology reference laboratory over a 6-month period were stained for Helicobacter, and the histologic and clinicopathologic parameters evaluated. RESULTS: Amongst 7663 Helicobacter-positive biopsies, 823 (10.7%) did not show typical chronic active gastritis with numerous Helicobacter organisms, and were therefore considered histologically atypical. Rare Helicobacter pylori organisms accounted for 58.0% of all atypical infections; the next most common atypical Helicobacter infection was that with minimal or no gastric inflammation (23.3% of atypical infections). Patients in these groups did not differ demographically from those with other forms of atypical or typical Helicobacter infection, although a small subgroup (6%) was more likely to have had a previously treated infection. CONCLUSIONS: In many of these atypical infections, Helicobacter would not have been suspected based on the histologic findings alone, and would have been missed without routine special stains. Performing a sensitive stain could prevent additional testing and allow prompt treatment of the affected patients, thus substantially reducing the risk for peptic ulcer and gastric cancer and preventing the transmission of the infection to family members.

Alkaline phosphatase is a useful cytochemical marker for the diagnosis of acute myelomonocytic and monocytic leukemia in the dog.

BACKGROUND: Immunophenotyping has replaced cytochemical staining as the preferred technique for classifying acute leukemia. However, some acute myeloid leukemias (AML) lack lineage-associated markers. In our experience, alkaline phosphatase (ALP) is expressed in immature canine monocytes. We hypothesized that ALP is a useful marker for monocytic AML. OBJECTIVES: The objective was to compare ALP expression in neoplastic cells from dogs with lymphoma, chronic lymphocytic leukemia (CLL), acute lymphoid leukemia (ALL), and AML. METHODS: Alkaline phosphatase results were retrieved from medical records of dogs with acute leukemia. Smears from dogs with lymphoma or leukemia were also prospectively stained for ALP activity. CLL was based on persistent lymphocytosis (10 × 10(9) /L) and acute leukemia on ≥ 20% blasts in blood or bone marrow. ALL was classified based on positive phenotyping for T- or B-lymphocyte antigens, and AML on positive phenotyping for CD11b, CD11c or CD14, or cytochemical staining for chloroacetate esterase, Sudan Black B, or myeloperoxidase. RESULTS: There was no ALP activity in all 49 lymphomas and 7 CLLs. Weak ALP activity was seen in 31% of 14 ALL (all T-ALL). ALP activity was seen in all 20 AML (P < .001 vs ALL) with strong activity in 64% (vs 25% ALL) in most neoplastic cells (median 75% vs 9% ALL, P = .020). Of AML, 80% were CD34+ (vs 39% ALL, P = .027) and 100% were MHCII- (vs 43% ALL, P = .002). CONCLUSIONS: ALP activity may be useful for AML confirmation in dogs, particularly if neoplastic cells only express CD34+ on immunophenotyping.