Performance of lymph node cytopathology in diagnosis and characterization of lymphoma in dogs

Background: Cytopathology is a minimally invasive and convenient diagnostic procedure, often used as a substitute for histopathology to diagnose and characterize lymphoma in dogs. Objectives: Assess the diagnostic performance of cytopathology in diagnosing lymphoma and its histopathological subtypes in dogs. Animals: One-hundred and sixty-one lymph node samples from 139 dogs with enlarged peripheral lymph nodes. Methods: Based only on cytopathology, 6 examiners independently provided the following interpretations on each sample: (a) lymphoma vs nonlymphoma; (b) grade and phenotype; and (c) World Health Organization (WHO) histopathological subtype. Histopathology and immunohistochemistry (IHC) findings were used as reference standards to evaluate diagnostic performance of cytopathology. Clinical, clinicopathologic, and imaging data also were considered in the definitive diagnosis. Results: Classification accuracy for lymphoma consistently was >80% for all examiners, whereas it was >60% for low grade T-cell lymphomas, >30% for high grade B-cell lymphomas, >20% for high grade T-cell lymphomas, and <40% for low grade B-cell lymphomas. Interobserver agreement evaluated by kappa scores was 0.55 and 0.32 for identification of lymphoma cases, and of grade plus immunophenotype, respectively. Conclusions and Clinical Importance: Cytopathology may result in accurate diagnosis of lymphoma, but accuracy decreases when further characterization is needed. Cytopathology represents a fundamental aid in identifying lymphoma and can be used as a screening test to predict grade and phenotype. However, these results must be confirmed using other ancillary techniques, including flow cytometry, histopathology, and immunohistochemistry (IHC)

Directing Astroglia from the Cerebral Cortex into Subtype Specific Functional Neurons

Forced expression of single defined transcription factors can selectively and stably convert cultured astroglia into synapse-forming excitatory and inhibitory neurons

Retrospective study of cytologic features of well-differentiated hepatocellular carcinoma in dogs.

Background: Cytologic diagnosis of hepatocellular carcinoma is possible when hepatocytes have prominent criteria of malignancy, but is problematic when hepatocytes have a relatively normal morphologic appearance. Objectives: The aim of this study was to determine the cytologic features of histologically confirmed well-differentiated hepatocellular carcinomas (WD-HCC) in dogs to develop reasonable criteria for an accurate diagnosis when obvious criteria of malignancy in hepatocytes are lacking. Methods: Slides of ultrasound-guided fine-needle aspirates of 15 histologically confirmed WD-HCC in dogs were evaluated retrospectively using a scoring system (0\u20133) established for 33 cytologic features. For comparison, 15 cytologic samples of non-nodular non-neoplastic liver were evaluated using the same criteria. Statistical analysis included multiple hypothesis testing using the Benjamini\u2013Hochberg method or false discovery rate control to correct for multiple comparisons. Results: The most significant and useful cytologic features in the diagnosis of canine WD-HCC were dissociation of hepatocytes, acinar or palisading arrangements of neoplastic cells, and the presence of naked nuclei and capillaries, together with mild anisocytosis, anisokaryosis, multinuclearity, and increased N:C ratios. Conclusions: Cytologic features of canine WD-HCC were determined. Further studies are warranted to compare these cytologic criteria among WDHCC, hepatomas, and hyperplastic nodules and to examine co-variance of the 33 cytologic features

Cytologic features of reactive fibroplasia in cutaneous and subcutaneous lesions of dogs: A retrospective study

Background: Determining reactive fibroplasia from primary neoplastic proliferation can be difficult using the cytologic features of spindle cells. Objectives: This study aimed to describe qualitative features of benign reactive spindle cells and provide a diagnostic tool to distinguish between fibroplasia and soft tissue sarcoma. Methods: Cytologic samples from cutaneous lesions with histopathologically confirmed fibroplasia were reviewed and compared with cytologic samples from confirmed low-grade soft tissue sarcomas. The samples were obtained from the Archive of the Laboratorio Veterinario Bresciano (Brescia; Italy). Results: A total of 25 cytologic samples retrieved from the database fit the selection criteria. For comparison, 25 cytologic samples of histopathologically confirmed soft tissue sarcomas with secondary inflammation were obtained and reviewed from the same database. A low number of singularly distributed spindle cells with mild features of atypia and a high ratio of inflammatory to spindle cells was observed in confirmed cases of fibroplasia. Conclusions: Low cellularity, individualized spindle cells, and an increased inflammatory-to-spindle cell ratio were more indicative of fibroplasia than sarcoma

Caratterizzazione diagnostica ultrastrutturale dei corpi ialini citoplasmatici in un caso di carcinoma epatocellulare canino

I1 carcinoma epatocellulare rappresenta una patologia rara nella specie canina (incidenza inferioreall'l%) ed il caso clinico oggetto del presente studio offi-e, da un lato, un esempio unicodell'importanza dell'esame ultrastmtturale nella caratterizzazione morfologica dei corpi inclusiintracitoplasmatici osservati nelle cellule neoplastiche - mai descritti nel cane - e, dall'altro, unospunto interessante per un approccio comparativo in chiave di "diagnosi differenzialeultrastrutturale" con analoghe lesioni nell'uomo.Un cane Yorkshire Terrier di 13 anni con letargia, disoressia e lieve polidipsia e parametriematobiochimici indicativi di una epatopatia (aumento delle concentrazioni sieriche di ALT, AST,ALP) presentava ecograficamente una neoformazione di origine epatica, diagnosticataistologicarnente come carcinoma epatocellulare di tipo trabecolare. Una caratteristica interessantedelle cellule neoplastiche era la presenza di corpi rotondeggianti eosinofilic, di circa 5-1 0 micron didiametro, occasionalmente circondati da un alone chiaro. Tali strutture risultavano positive allacolorazione PAS e negative per citocheratine, al-antitripsina, IgG, IgM, fibrinogeno, CEA. Dalpunto di vista ultrastrutturale, gli inclusi citoplasmatici presentavano un aspetto omogeneogranulare elettrondenso ed, in alcuni casi, erano circondati da residui di membrana del RER. Gliinclusi di dimensioni inferiori, con aspetto omogeneo o reticolato della matrice, erano distribuitiall'interno delle cisterne dilatate del RER.In base alle caratteristiche ultrastmtturali descritte, tali inclusi sono stati definiti come corpiialini globulari (Kojiro, 2006) o granuli intracistemali (Ghadially, 1997). L'esame ultrastrutturale,associato ai risultati istochimici ed irnmunoistochimici, ha consentito di escludere i corpi diMallory, i corpi ialini fibrillari, i corpi pallidi ("pale bodies") ed i globuli contenenti al antitripsinadescritti nei carcinomi epatici dell'uomo. Le caratteristiche ultrastmtturali degli inclusicitoplasmatici osservati nel caso clinico in esame indicano, quindi, l'accumulo di materialeproteinaceo condensato conseguente a malformazioni o disfunzioni del RER e ad alterazioni dellasecrezione proteica da parte delle cellule neoplastiche.[...