Intestinal Lesions Due to Rhodococcus equi in a Patient With Advanced Retroviral Disease and Pulmonary Infection: A Case of Colonic Malakoplakia.

In humans, Rhodococcus equi (R. equi) is a zoonotic infection usually involving immunocompromised subjects, only rarely affecting immunocompetent subjects. Herein, we describe an R. equi infection in a 50-year-old Russian man with acquired immune deficiency syndrome (AIDS) who presented with pulmonary cavitary lesions and clinical manifestation of colonic malakoplakia. A colonoscopy examination showed ulceration and mucosal erosion, and the histological findings confirmed the colonic malakoplakia. The patient recovered from pulmonary and gastrointestinal disease after four weeks of antibiotic treatment with intravenous ciprofloxacin and oral azithromycin and also underwent subsequent long-term oral antibiotic treatment to achieve clinical and immune restoration after antiretroviral therapy. Infectious disease pathology subspecialties should always consider R. equi chronic infection as a cause of malakoplakia in patients with AIDS. As only a few cases of colonic malakoplakia associated with R. equi are reported in the literature, these cases are important to describe, especially for clinical and treatment management.

Correlation between cytology Oil Red O staining and lung biopsy specimens: utility of the lipid-laden macrophage index.

INTRODUCTION: Oil Red O staining is used for enumeration of the lipid-laden macrophage index (LLMI) as a surrogate for aspiration. As part of quality improvement efforts aimed at optimizing resource utilization, the utility of this stain in current cytopathology practice was re-evaluated. The objective of this study was to explore the clinical utility of Oil Red O staining in bronchoalveolar lavage (BAL) samples by correlating the LLMI with findings in concurrent histologic tissue samples. MATERIALS AND METHODS: Lung transbronchial biopsy specimens that suggested aspiration that were submitted with concurrent BAL cytology samples were retrieved. Lung tissue biopsies were reviewed for the presence of foamy alveolar macrophages (graded as 0, 1+, and 2+), foreign material, and giant cells. The concurrent BAL was reviewed with consensus determination of the LLMI. RESULTS: A total of 53 cases were identified. On histology, 13 cases (24.5%) were found to have no foamy alveolar macrophages, 23 cases (43.4%) were found to have 1+ foamy alveolar macrophages, and 17 cases (32.1%) were found to have 2+ foamy alveolar macrophages. Six cases (11.3%) were found to have foreign material, and 10 cases (18.9%) were found to have multinucleated giant cells. The average LLMI score was 16, with 44 (83.0%) in the low range (LLMI <40) and 9 (17.0%) in the intermediate range (LLMI of 40-90). CONCLUSIONS: None of the cases in our study had an LLMI that exceeded the cutoff value for which aspiration would be suspected. We found no correlation of the LLMI with lung biopsies that suggested aspiration.

Dentinogenic Ghost Cell Tumor in a Sumatran Rhinoceros.

An adult female Sumatran rhinoceros was observed with a swelling in the left infraorbital region in March 2017. The swelling rapidly grew into a mass. A radiograph revealed a cystic radiolucent area in the left maxilla. In June 2017, the rhinoceros was euthanized. At necropsy, the infraorbital mass measured 21 cm × 30 cm. Samples of the infraorbital mass, left parotid gland, and left masseter muscle were collected for histopathology (Hematoxylin & Eosin, Von Kossa, Masson's trichrome, cytokeratin AE1/AE3, EMA, p53, and S-100). Numerous neoplastic epithelial cells showing pleomorphism and infiltration were observed. Islands of dentinoid material containing ghost cells and keratin pearls were observed with the aid of the two special histochemistry stains. Mitotic figures were rarely observed. All the neoplastic odontogenic cells and keratin pearls showed an intense positive stain for cytokeratin AE1/AE3, while some keratin pearls showed mild positive stains for S-100. All samples were negative for p53 and S-100 immunodetection. The mass was diagnosed as a dentinogenic ghost cell tumor.

Application of Immunohistochemistry and Special Staining Technique in Forensic Traumatic Pathology Identification. / å ç–«ç»„ç»‡åŒ–å­¦åŠç‰¹æ®ŠæŸ“è‰²æŠ€æœ¯åœ¨æ³•åŒ»æŸä¼¤ç— ç†å­¦é‰´å®šä¸­çš„åº”ç”¨.

In forensic traumatic pathology practice, immunohistochemistry and special staining technique play an important role in wound age estimation and complications of traumatic complication identification. They even play an important role in the identification of special cases, such as snakebites and insulin killings. This article reviews the application and value of immunohistochemistry and special staining techniques in forensic traumatic pathology based on the cases of forensic practice reported in literature.

Application of Immunohistochemistry and Special Staining Technique in Forensic Traumatic Pathology Identification / 法医学杂志

In forensic traumatic pathology practice, immunohistochemistry and special staining technique play an important role in wound age estimation and complications of traumatic complication identification. They even play an important role in the identification of special cases, such as snakebites and insulin killings. This article reviews the application and value of immunohistochemistry and special staining techniques in forensic traumatic pathology based on the cases of forensic practice reported in literature.

Oil red O staining for lipid-laden macrophage index of bronchoalveolar lavage: interobserver agreement and challenges to interpretation.

INTRODUCTION: Oil Red O (ORO) staining on cytologic specimens with calculation of the lipid-laden macrophage index (LLMI) is used as a part of the workup in a number of clinical settings, particularly when aspiration is of concern. As a part of ongoing internal quality improvement measures, the objective of the present study was to evaluate the interobserver agreement of the LLMI calculation and to identify factors that affect the variability of the calculation. MATERIALS AND METHODS: There were 9 study participants, which included 3 trainees, 3 cytotechnologists, and 3 cytopathologists. Each participant reviewed 100 ORO-stained bronchoalveolar lavage slides and assigned an LLMI score to each case. The scores were categorized into 3 groups according to the associated aspiration risk: low, LLMI <40; intermediate, LLMI 40 to 90; and high, LLMI >90. The participants were also requested to note any challenges to the calculation for each case. RESULTS: The interobserver agreement among all participants was fair (κ = 0.23). Stratified by participant group, the interobserver agreement among the trainees was fair (κ = 0.24), among cytotechnologists was fair (κ = 0.32), and among cytopathologists was moderate (κ = 0.60). In 70 cases, at least one participant scored the case at least one category higher than the other participants; in 47 cases there was a two category difference. A primary diagnostic challenge reported by participants was macrophage pigmentation (hemosiderin, anthracosis). CONCLUSIONS: We found only fair interobserver agreement among all 9 participants in the study. Hemosiderin and anthracotic pigmentation was a major factor impeding LLMI calculation resulting in overestimation of the LLMI.

Evaluation of the clinical utility of reflex GMS and AFB stains on BAL specimens from lung transplant patients.

INTRODUCTION: Bronchoalveolar lavage (BAL) has a useful role in the detection of infectious diseases. Grocott methenamine silver (GMS) and acid-fast bacilli (AFB) are ancillary stains that aid in the cytologic detection of fungal and mycobacterial organisms. However, the utility of these stains in conjunction with microbiological testing is unclear. MATERIALS AND METHODS: BAL specimens from lung transplant patients between January 1, 2018, to December 31, 2018, were evaluated. Inclusion criteria included cases with both GMS and AFB stains and concurrent fungal and mycobacterial microbiology testing. The staining findings were correlated with concurrent microbiology findings, including cultures and immunofluorescent smears. RESULTS: A total of 231 BAL specimens were identified. GMS stain was positive in 19.5% and AFB in 1.3%. Fungal microbiology was positive in 23.4% and mycobacterial microbiology in 6.1%. A total of 87.9% of cases had concordant findings between cytology stains and microbiology tests and 12.1% had discrepant findings. Notably of the discrepancies, 3.0% had positive GMS and negative fungal microbiology and 6.9% had positive fungal microbiology and negative GMS. No cases had positive AFB with negative mycobacterial microbiology whereas 4.8% had positive mycobacterial microbiology and negative AFB stain. CONCLUSIONS: We show that staining for AFB on BAL material in lung transplant patients had limited benefit when concurrent microbiology was performed. GMS staining shows a small benefit. We recommend reflex testing for fungal organisms but not mycobacterial organisms in lung transplant patients.

A Rapid Special Staining Technique for Identification of Normal Ureter by Frozen Section in Children With Ureteropelvic Junction Obstruction.

BACKGROUND: The exact etiology of ureteropelvic junction obstruction (UPJO) is unknown, and inadequate excision of the narrow segment has been proposed as a cause of failure in 5% to 7% of cases of pyeloplasty. AIMS: To study whether frozen section can be useful to detect normal ureter distal to UPJO during pyeloplasty. METHODS: Histological sections from 31 patients with UPJO were analyzed for collagen to muscle ratio (CMR) on conventional (formalin) and rapid (frozen section) Masson's trichrome staining. Pathological findings were correlated with postoperative outcomes analyzed at 1-year follow-up and expressed as excellent, moderate, or mild improvement, static and deterioration based on ultrasound grade, differential renal function, and renogram drainage pattern. RESULTS: There was a very strong positive correlation (r = .94; P = .001) between CMR by conventional and rapid frozen Masson's trichrome staining. There was a very strong negative correlation between pyeloplasty outcomes and CMR on conventional staining (r = -.94; P = .001) or rapid frozen Masson's trichrome staining (r = -.91; P = .001). Regression analysis revealed that a CMR of 1.2 or less (95% confidence interval: 1.9-0.7) was associated with a successful outcome. CONCLUSIONS: It is feasible to intraoperatively identify normal ureter distal to UPJO using CMR analysis on the novel rapid frozen section technique reported.

Periodic Acid-Schiff Staining with Diastase.

Periodic Acid-Schiff (PAS) with diastase (PAS-D) refers to the use of the PAS stain in combination with diastase, which is an enzyme that digests the glycogen. The purpose of using the PAS-D procedure is to differentiate glycogen from other PAS-positive elements in tissue samples. The PAS-D method is also used for periportal liver staining of AAT polymer inclusions that are seen in alpha-1 antitrypsin deficiency disease. Here, we describe the procedure of PAS-D staining in formalin-fixed, paraffin-embedded human liver tissues.

Diagnostic Implication and Clinical Relevance of Ancillary Techniques in Clinical Pathology Practice.

Hematoxylin-eosin-stained slide preparation is one of the most durable techniques in medicine history, which has remained unchanged since implemented. It allows an accurate microscopic diagnosis of the vast majority of tissue samples. In many circumstances, this technique cannot answer all the questions posed at the initial diagnostic level. The pathologist has always been looking for additional ancillary techniques to answer pending questions. In our daily histopathology practice, we referred to those techniques as special stains, but nowadays, they are more than stains and are collectively called ancillary tests. They include a wide range of techniques starting from histochemical stains and ending in one or more advanced techniques, such as immunohistochemistry, immunofluorescence, molecular studies, cytogenetic studies, electron microscopy, flow cytometry, and polymerase chain reaction.

Histopathology and Histochemistry in Cutaneous Fungal Infections / 대한의진균학회지

Dermatomycosis refers to any fungal infection of the skin and may be caused by dermatophytes, yeast, or other fungi, including those that do not usually cause cutaneous disease. Clinical diagnosis of a dermatomycosis can be confirmed by microscopic detection of fungal elements, by identification of the species through culture, or by histologic evidence of the presence of fungal material in the tissue. In superficial mycoses, direct smear with KOH and fungal culture are the most valuable and useful diagnostic methods. For this reason, skin biopsy is not often employed in the workup of dermatophytosis or other superficial mycoses. But it is useful in diagnosis of deep fungal infections and some lesions in which KOH examination of scale is negative. This review article aims to provide insights on the histopathology and various special stains in diagnosing dermatomycosis.

The mystery of the vanishing Reinke crystals.

Reinke crystals (RC) are pathognomonic of Leydig cells (LCs); they are thought to be rare in normal testes and to occur only in approximately one third of LC tumors. We noticed that crystals present in touch imprint and frozen sections of an LC tumor disappeared after tissue fixation. This phenomenon led us to hypothesize that their reported low frequency in normal and neoplastic LCs may be secondary to degradation/dissolution of the crystals after formalin fixation. Our review of the literature also led us to hypothesize that RC are better preserved after air-drying and alcohol fixation. We collected testicular samples from 21 autopsies including air-dried cytologic preparations and tissue samples that were fixed in alcohol or formalin. We found that RC are common in normal LC but dissolve rapidly in formalin and slowly and only partially in alcohol. The composition of RC is unknown; however, they have been reported to stain specifically for nestin, an intermediate filament expressed mainly in neural and muscle tissue. Because the crystals have only been described in androgen-producing cells, we hypothesized that the crystals may represent a crystallized form of androgenic hormones, hormone complexes, or enzymes involved in their synthesis. We performed immunostains for androgens and enzymes involved in androgenesis. We also performed nestin immunostain to confirm the previous study. The crystals stain specifically with antibodies anti-3ß-hydroxysteroid dehydrogenase and are negative for the remaining androgenic enzymes, androgenic hormones, and nestin.