A comparison of cytologic quality in fine-needle specimens obtained with and without aspiration from superficial lymph nodes in the dog

Performance of Culture Using a Semi-Automatic Needle as a Novel Tool for Collecting Lymph Node Samples for the Diagnosis of Canine Visceral Leishmaniasis

Zoonotic visceral leishmaniasis is caused by Leishmania (Leishmania) infantum and dogs are the main domestic reservoir. This study compared the performance of parasitological tests using semi-automatic needle puncture (SANP) for collecting popliteal lymph node samples with samples collected from the same lymph node by fine needle aspiration puncture (FNAP) and by necropsy for the diagnosis of canine visceral leishmaniasis (CVL). Popliteal lymph node samples were collected from 30 CVL-seropositive dogs from an endemic region in Brazil. After clinical examination and euthanasia, samples were collected from the same lymph node by SANP, FNAP, and necropsy. The reference tests were culture, immunohistochemistry, and histopathology. Positivity for Leishmania spp. was 70% for immunohistochemistry and 33.3% for histopathology. Culture positivity using the different sampling techniques was 77% for necropsy (87% in the first week), 73% for FNAP (82% in the first week), and 63% for SANP (95% in the first week). The combination of SANP and culture proved to be an alternative for the diagnosis of Leishmania spp. in the lymph node samples of dogs because of its high positivity rate and because it is more practical and faster and has a shorter time to positivity by culture when compared to FNAP and necropsy sampling.

An immersive simulation strategy to teach cytology sample collection methods and basic diagnosis skills: A two academic center study

BACKGROUND

Collecting cytology samples and making simple diagnoses are skills taught in veterinary universities, mostly in a passive way. Simulators enhance practical skills learning, increasing student engagement through immersive activities. These strategies have not been carefully assessed in veterinary cytology.

OBJECTIVES

This study aimed to describe a simulator developed for training cytology sample collection methods and assess the utility of an immersive simulation strategy to learn and practice the collection of cytology samples.

METHODS

A flipped classroom with a station design was followed. Students first watched video tutorials on sampling collection, listened to brief cases' clinical histories, and moved to immersive simulator stations. There, they practiced imprints, swabs, and fine-needle aspiration (FNA). Microscopic observation of the material was available through augmented reality tools. Students were evaluated by Objective Structured Clinical Examination (OSCE) tools on their ability to perform FNA on stuffed animal models. Students answered two questionnaires addressing their learning outcomes.

RESULTS

Second- and third-year students from two centers (n = 129) practiced cytologic collection methods in simulators which significantly changed their willingness to perform FNA in live animals after the class activities. OSCE pass rates over 90% were obtained for most steps of FNA, and students rated the activity as essential/very relevant for learning.

CONCLUSIONS

Immersive simulation strategies were effective at increasing student comfort with cytologic sampling techniques. This approach should be included in the veterinary curriculum as it can increase the quality of cytology samples and could potentially improve the cytologic diagnosis of a submitted sample.

Diagnostic quality of ultrasound-guided fine-needle aspirates samples from the canine liver and spleen is not significantly affected by using 22-, 23-, and 25-gauge needles

Ultrasound-guided fine-needle aspirates (FNA) of the liver and spleen for cytological analysis are a commonly performed procedure in canine veterinary practice. Based on our review of the literature, this is the first published study investigating whether needle size affects the diagnostic quality of hepatic and splenic samples. The aim of this prospective analytical study was to compare the diagnostic quality of ultrasound-guided FNA cytological samples of canine liver and spleen based on cellularity, blood contamination, and overall cell preservation between three different needle sizes (22-, 23-, and 25-gauge). A total of 282 splenic aspirates from 94 dogs and 348 hepatic aspirates from 116 dogs were enrolled in the study and examined by two board-certified veterinary clinical pathologists. In this study, no significant differences in diagnostic quality were identified between different needle gauge sizes when sampling canine liver and spleen. Blood contamination was higher using 22-gauge needles compared with 25-gauge needles (P = 0.024) when sampling the liver.