Getting to the point: indications for fine-needle aspiration of internal organs and bone

Diagnostic yield of percutaneous, ultrasound-guided, fine needle aspirates of the gastrointestinal wall: a retrospective analysis of 152 samples

OBJECTIVES

The aim was to assess the technical success of percutaneous ultrasound-guided fine needle aspirates of gastrointestinal wall lesions and evaluate predictors of success. Secondary aims included comparing the cytological diagnosis with histopathology, evaluating the utility of concurrent locoregional lymph node cytology and assessing the procedure's complication rate.

MATERIAL AND METHODS

Gastrointestinal wall cytology from 75 dogs and 70 cats obtained between 2018 and 2023 were reviewed and categorised as successful (resulting in a diagnostic cytology report) and accurate (resulting in the correct diagnosis when compared to histopathology). Unsuccessful fine needle aspirates, not submitted for cytology, were not recorded. Variables recorded included animal signalment, lesion and lymph node's appearance on ultrasound, size, location, number of smears submitted and experience of the ultrasonographer.

RESULTS

One hundred and fifty-two reports were analysed. Eighty-eight (58%) were successful: three normal epithelium, 21 inflammatory processes and 64 neoplasms. Variables associated with increased technical success included description of a mass, higher number of slides submitted and thickness of gastrointestinal lesion on ultrasound. Comparison with histopathology, performed for 17 lesions, showed discrepancies in eight, complete agreement in seven and partial in two. Eighty-four loco-regional lymph nodes were sampled, of which, 67 were successful (80%) and 52 brought additional clinical information (supporting GI wall cytology or diagnosing neoplasia not identified on GI wall cytology). No complication strictly attributable to gastrointestinal wall sampling was reported but when possibly related, death of the patient occurred in 2.5% of cases.

CLINICAL SIGNIFICANCE

Ultrasound-guided fine needle aspirate of gastrointestinal wall had moderate accuracy and was unsuccessful in 42% of cases, but technical success increased when sampling mass lesions, thicker intestinal layers and submitting more slides.

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.

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

OBJECTIVES

To assess the impact of aspiration on cytologic quality of fine-needle specimens obtained from lymph nodes of dogs and to compare the level of agreement of the cytologic diagnosis between the two sampling techniques.

MATERIALS AND METHODS

Fifty-three client-owned dogs were prospectively enrolled. Client-owned dogs were prospectively enrolled in the study if cytologic examination of lymph nodes was indicated in the course of their clinical diagnostic work-up. In each dog, two superficial, palpably accessible lymph nodes were sampled: one by fine-needle aspiration and the other by fine-needle non-aspiration, using a 21-Gauge needle with or without a 5-mL syringe. Cytologic quality was assessed in duplicate smears assessed by two observers who rated cellularity, blood contamination, thickness, cell preservation and cytoplasmic fragmentation using a predefined scoring system.

RESULTS

Fifty-three client-owned dogs were included in the study. No significant difference was found in rating scores between the two sampling techniques for any of the cytologic quality parameters assessed. Cohen's kappa coefficient was 0.84 (95% confidence interval 0.68-1.00), indicating diagnostic agreement between the sampling techniques.

CLINICAL SIGNIFICANCE

In this study, both fine-needle aspiration and fine-needle non-aspiration techniques yielded lymph node specimens of comparable cytologic quality and with acceptable agreement in cytologic diagnosis.

Safety of percutaneous ultrasound-guided fine-needle aspiration of adrenal lesions in dogs: Perception of the procedure by radiologists and presentation of 50 cases

Background

Percutaneous ultrasound (US)‐guided fine‐needle aspiration (FNA) of adrenal gland lesions is controversial in veterinary medicine.

Objective

To evaluate the frequency and radiologists' perception of the risk of the procedure as well as determining the incidence of complications.

Methods

Retrospective study. A first survey was submitted by e‐mail to all board‐certified radiologists of the American College of Veterinary Radiology (ACVR) and European College of Veterinary Diagnostic Imaging (ECVDI). A second survey was sent to radiologists who declared having performed the procedure at least once in their career (observational cross‐sectional case study).

Results

The first survey was sent to 977 diplomates and answered by 138. Of 138 diplomates, 40 currently performed the procedure and 98 did not; 44 of the 98 gave the hypertensive crisis risk in pheochromocytoma as a reason. To the second survey, 12 of 65 responded positively; 50 dogs with 58 lesions were recruited, including 23 pheochromocytomas. Complications were reported in 4 of 50 dogs; 3 hemorrhages (1 mild and 1 moderate) and 1 death from acute respiratory distress syndrome (possibly related to laryngeal paralysis). No hypertensive crisis was reported. There was no relationship between the method of FNA/type of needle used and occurrence of complications. Based on the recollection of these 65 radiologists, who performed approximately 200 FNA of adrenal lesions, a death rate of approximately 1% was estimated.

Conclusions and Clinical Importance

Percutaneous US‐guided FNA of adrenal lesions can be considered a minimally risky procedure, despite the negative perception by radiologists.

An Unusual Case of Metastatic Seminoma in a Dog

An 8 yr old, reportedly castrated male Boston terrier presented with a history of generalized hyperesthesia and intermittent shifting leg lameness. Physical examination revealed a caudal abdominal mass and bilateral shoulder pain. A complete blood count, serum biochemistry panel, and urinalysis were unremarkable. Thoracic radiographs demonstrated bony proliferation and lysis of the third sternebra, an expansile lesion of the left tenth rib, and lucency in both proximal humeral metaphyses. Abdominal radiographs and ultrasound revealed a soft tissue mass within the caudoventral right abdomen. Ultrasonography also revealed an enlarged lymph node within the right retroperitoneal space. Exploratory laparotomy identified the mass as a retained testicle. A cryptorchidectomy, lymph node biopsy, and bilateral percutaneous core biopsies of the proximal humeri were performed. Histopathologic examination revealed malignant seminoma of the testicle with metastasis to lymph node and bone. Adjuvant chemotherapy was recommended, but it was declined by the owner. All follow-up was lost. This case highlights a unique case for causative hyperesthesia secondary to a novel site of metastasis from malignant seminoma. Metastasis to bone has not been reported in humans or dogs and represents a very unusual and aberrant variant of the normally relatively benign biological behavior of seminoma in the dog.

Safety of ultrasound-guided fine-needle aspiration of the feline pancreas: a case-control study

The safety of fine-needle aspiration (FNA) of the feline pancreas has not been reported. The incidence of complications following ultrasound-guided pancreatic FNA in 73 cats (pancreatic aspirate [PA] cats) with clinical and ultrasonographic evidence of pancreatic disease was compared with complications in two groups of matched control cats also diagnosed with pancreatic disease that either had abdominal organs other than the pancreas aspirated (control FNA, n = 63) or no aspirates performed (control no FNA, n = 61). The complication rate within 48 h of the ultrasound and/or aspirate procedure did not differ among the PA cats (11%), control FNA (14%) or control no FNA (8%) cats. There was no difference in rate of survival to discharge (82%, 84% and 83%, respectively) or length of hospital stay among groups. The cytologic recovery rate for the pancreatic samples was 67%. Correlation with histopathology, available in seven cases, was 86%. Pancreatic FNA in cats is a safe procedure requiring further investigation to establish diagnostic value.