Immunohistochemical characterization of mesothelioma in 6 large felids

Cardiac osteochondrolipoma in a cheetah

A 13-y-old captive female cheetah (Acinonyx jubatus) succumbed following the acute onset of respiratory distress. Autopsy revealed bacterial bronchopneumonia as the primary cause of death. Additionally, splenic myelolipomas and systemic amyloidosis were identified postmortem. Interestingly, a solitary, firm nodule was found in the right atrial wall, consisting histologically of mature adipocytes with partial osseous and cartilaginous differentiation, consistent with osteochondrolipoma. Hepatic congestion suggested right heart failure. Although the direct impact of the cardiac mass on heart function remains unclear, its potential contribution to the fatal outcome cannot be discounted. To our knowledge, cardiac osteochondrolipoma has not been reported previously in cheetahs or other animals.

Integrated DNA methylation analysis of peripheral blood from asbestos exposed populations and patients with malignant mesothelioma reveals novel methylation driver genes of diagnostic and prognostic relevance

Effective biomarkers are paramount importance for the early detection and prognosis prediction of malignant mesothelioma (MM) which mainly caused by asbestos exposure, and DNA methylation has been demonstrated to be a potentially powerful diagnostic tool. To elucidate the relationship between asbestos exposure and alterations in DNA methylation patterns, as well as the potential diagnostic and prognostic value of differentially methylated regions and CpG sites (DMRs/DMCs) in the progression of MM. The current study employed reduced representation bisulfite sequencing (RRBS) to examine the genome-wide DNA methylation profiles in the peripheral blood of individuals exposed to asbestos and those diagnosed with MM, in comparison to the controls, and DMRs/DMCs were subsequently validated by targeted bisulfite sequencing (TBS). Our results suggested that there were 12 DMRs/DMCs exhibiting a consistent change trend of DNA methylation in both RRBS and TBS results. Significant correlations were observed between DNA methylation levels of DMRs/DMCs and the duration of occupational asbestos exposure. The evaluation of the receiver operating characteristic (ROC) curve suggested that the DNA methylation status of FHIT, CCR12P and CDH15 may serve as diagnosis indicator in distinguishing MM patients from healthy controls and those exposed to asbestos. Our findings offer a foundation for the role of DNA methylation in the development of MM induced by asbestos exposure. The potential significance of FHIT, CCR12P and CDH15 DNA methylation alterations in the pathogenesis and advancement of MM disease suggests their potential as diagnostic and prognostic biomarkers.

PRIMARY HEPATIC NEOPLASIA IN THREE ADULT BAMBOO SHARKS (CHILOSCYLLIUM PLAGIOSUM AND CHILOSCYLLIUM PUNCTATUM) IN AN AQUARIUM POPULATION

Neoplasia in elasmobranchs is uncommonly documented. This report describes primary hepatic neoplasia in three adult female bamboo sharks under managed care: biliary adenocarcinoma in a whitespotted bamboo shark (Case 1; Chiloscyllium plagiosum), biliary adenocarcinoma in a brownbanded bamboo shark (Case 2; Chiloscyllium punctatum), and hepatocellular carcinoma in a whitespotted bamboo shark (Case 3). Case 1 presented with extensive cutaneous papillomas and was electively euthanized. At necropsy, a 4-cm-diameter, pale-tan, firm hepatic mass was identified and diagnosed histologically as a biliary adenocarcinoma. Case 2 presented with decreasing body condition despite normal food intake. Coelomic ultrasound and exploratory surgery revealed several large masses in both hepatic lobes, and the patient was euthanized. At necropsy, nine, 1-6-cm-diameter, black to tan, firm hepatic masses were identified and diagnosed histologically as biliary adenocarcinoma with branchial intravascular neoplastic emboli. Case 3 presented for routine health examination and was euthanized for diagnostic purposes after coelomic ultrasound revealed multiple hepatic masses. At necropsy, two 1-3-cm-diameter, brown- and-black mottled, firm hepatic masses were identified and diagnosed histologically as hepatocellular carcinoma. Immunohistochemistry was performed in two of these cases and was noncontributory, likely because of a lack of cross reactivity between antibodies (antipancytokeratin) and elasmobranch tissues.

Chemosensitivity of three patient-derived primary cultures of canine pericardial mesothelioma by single-agent and combination treatment

INTRODUCTION

Canine mesothelioma is a rare malignant tumor that mostly affects body cavities, such as the pericardial and pleural cavities. Chemotherapy plays a crucial role in the treatment of canine mesotheliomas. We aimed to compare the antitumor effects of single-agent and combination chemotherapeutic agents on patient-derived primary cultures of canine pericardial mesothelioma established in this study. We planned to generate xenograft models for future studies.

MATERIAL AND METHODS

Effusion samples were collected from three dogs with histologically diagnosed pericardial mesothelioma and used for primary culture. Cultured cells were characterized by immunostaining for pan-cytokeratin AE1/AE3, vimentin, Wilms' tumor suppressor gene 1 (WT1), and cytokeratin 5 (CK5). To assess the tumorigenic properties of cells in the effusion and generate a xenograft model, the cell suspension was injected into a severe combined immunodeficient (SCID) mouse either subcutaneously (SC) or intraperitoneally (IP). Lastly, chemosensitivity of established primary cultures against four drugs, doxorubicin, vinorelbine, carboplatin, and gemcitabine, by single-agent treatment as well as combination treatment of carboplatin at a fixed concentration, either 10 or 100 μM, and gemcitabine at different concentrations ranging from 0-1000 μM was assessed by cell viability assay.

RESULTS

Primary cultures were successfully generated and characterized by dual positivity for AE1/AE3 and vimentin and positive staining for WT-1 and CK5, confirming the mesothelial origin of the cells. In the xenograft models, SC mouse developed a subcutaneous mass, whereas IP mouse developed multiple intraperitoneal nodules. The masses were histopathologically consistent with mesotheliomas. The chemosensitivity assay revealed that carboplatin had the highest anti-tumor effects among the four tested single-agent treatments. Furthermore, carboplatin at 100 μM combined with gemcitabine at clinically relevant doses demonstrated the augmented anti-tumor effects compared to single-agent treatment.

DISCUSSION AND CONCLUSION

Primary cultures and xenograft models generated in this study could be useful tools for in vitro and in vivo studies of canine mesothelioma. Carboplatin is a highly effective chemotherapeutic agent against canine mesothelioma when used as a sole agent and in combination with gemcitabine.

Pericardial malignant mesothelioma diagnosed in a dog by immunocytochemistry of the pericardial fluid: a case report

BACKGROUND

Pericardial effusions are one of the most common cardiac diseases in dogs. Common causes of haemorrhagic pericardial effusions include neoplasia, such as hemangiosarcoma, mesothelioma, chemodectoma, and ectopic thyroid tumours, and benign idiopathic pericardial effusion. Distinguishing among reactive mesothelial cells, malignant mesothelioma, and adenocarcinoma in body effusions is a diagnostic challenge. Therefore, the author aimed to discover whether the observed cells were reactive mesothelial, mesothelioma, or adenocarcinoma cells through immunocytochemistry using five markers (cytokeratin, vimentin, desmin, E-cadherin, and calretinin) in a canine patient.

CASE PRESENTATION

A 2.1 kg, spayed female, 10-year-old Yorkshire Terrier dog presented to a local hospital with dyspnoea and was evaluated for pericardial effusion. The presence of pericardial fluid was confirmed, and she was referred to our hospital for further evaluation. In cytological evaluation, cells shed individually or in clusters were observed, along with numerous non-degenerative neutrophils and macrophages. The cells showed binucleation, anisocytosis, anisokaryosis, abnormal nucleoli, abundant basophilic cytoplasm, high nuclear-cytoplasmic ratio, and coarse chromatin. Large atypical multinucleate cells were also observed. Erythrophagia was observed, indicating chronic haemorrhage. Immunocytochemistry using pericardial fluid was positive for cytokeratin, vimentin, desmin, E-cadherin, and calretinin. Therefore, malignant mesothelioma was diagnosed.

CONCLUSIONS

Immunocytochemistry is a very useful diagnostic technique because it can determine whether several fluorescent markers are simultaneously expressed in the same cell. Further, E-cadherin and calretinin can be used for the differential diagnosis of reactive mesothelial cells, malignant mesothelioma, and adenocarcinoma in dogs.