Background Thyroid nodules are stratified through fine-needle aspiration (FNA) and are often categorized using The Bethesda System for Reporting Thyroid Cytopathology, which estimates the risk of malignancy for six cytopathological categories. The atypia of undetermined significance (AUS) and follicular lesion of undetermined significance (FLUS) categories have varying malignancy rates reported in the literature which can range from 6 to 72.9%. Due to this heterogeneity, we assessed the malignancy rate and effectiveness of repeat FNA (rFNA) for AUS/FLUS thyroid cytopathology at our institution. Methods Electronic health records of patients with AUS/FLUS thyroid cytopathology on FNA at our center since the implementation of the Bethesda System on May 1, 2014–December 31, 2019 were retrospectively reviewed. Patient demographics, treatment pathway, and pathology results were collected. The treatment pathway of the nodules, the rFNA results, and the malignant histopathology results were reported. Malignancy rates were calculated as an upper and lower limit estimate. Results This study described 182 AUS/FLUS thyroid nodules from 177 patients. In total, 24 thyroid nodules were deemed malignant upon histopathology, yielding a final malignancy rate of 13.2–25.3%. All of the malignancies were variants of papillary thyroid carcinoma. The malignancy rate of the nodules which underwent resection without rFNA (21.5%) was lower than the malignancy rate of the nodules which underwent resection after rFNA (43.8%). 45.5% of the rFNA results were re-classified into more definitive categories. Conclusion The malignancy rate of AUS/FLUS thyroid cytopathology at our center is in line with the risk of malignancy stated by the 2017 Bethesda System. However, our malignancy rate is lower than some other Canadian centers and approximately half of our rFNAs were re-classified, highlighting the importance of establishing center-specific malignancy and rFNA re-classification rates to guide treatment decisions.

Squamous cell carcinoma (SCC) of the bladder is uncommon, but can arise in the setting of long-term bladder catheterization and chronic inflammation. SCC can arise primarily from the suprapubic catheter tract, but fewer than 10 such cases have been reported. We document 2 cases of SCC arising from the suprapubic tract associated with chronic indwelling urinary catheters. SCC must be differentiated from granulomatous conditions, which are quite common in patients with suprapubic catheters. IntroductionSquamous cell carcinoma (SCC) of the bladder is a rare condition in the general population, making up about 5% of all bladder tumours.1 Risk factors for SCC of the bladder include states of chronic inflammation and infection, such as long-term indwelling catheters or infection with Schistosoma haematobium primarily in endemic regions. 2A higher incidence of SCC in the spinal cord injury (SCI) population has been documented on the order of 2% to 10% beyond 10 years of catheterization.3-6 Among patients with SCI, about 50% of cases of primary bladder cancer are SCC. The risk is thought to stem from irritation and inflammation related to the chronic use of both urethral and suprapubic catheters, 3,7 chronic infections, 8 bladder stones 8 or, possibly, the inherent pathology of the neurogenic bladder itself. 5Although patients requiring long-term indwelling catheters are at increased risk of developing SCC, those with suprapubic catheters may more rarely develop SCC arising primarily from the suprapubic tract itself. This has been described in only a handful of cases. [9][10][11][12][13] We present 2 additional patients who developed SCC arising from their suprapubic catheter sites and discuss their surgical management and outcomes. Case 1A 55-year-old male, with a history of paraplegia secondary to spinal tuberculosis acquired at 16 years of age, presented with a 15-month history of an expanding, large, fungating lesion encircling his suprapubic catheter site. The catheter had been inserted within the first year of the onset of paraplegia. The patient's history was otherwise unremarkable and he was a lifelong non-smoker. There was no history of travel to areas endemic with Schistosoma haematobium. Examination of the lesion revealed an area of 15-cm in maximum diameter around the catheter site (Fig. 1). A biopsy of the lesion was diagnostic for SCC.Cystoscopy revealed a contracted bladder, but no evidence of stones, fistulae, or tumours of the mucosa or suprapubic tract. Biopsies of the bladder and suprapubic tract were negative for malignancy. Computed tomography (CT) showed infiltration of the mass into the anterior bladder wall, extending into the deep subcutaneous tissue and abdominal wall musculature (Fig. 2). Lymph nodes were negative. Subsequent bone scan was negative for bony metastases.Excision of the tumour was carried out by both the urology and plastic surgery services. Intra-operatively, the tumour invaded the anterior rectus fascia, rectus abdominus, periosteum of the pubic symphysis and spermatic ...

Background Urinary cytology is routinely used in the diagnosis of urothelial neoplasms, with good sensitivity for high‐grade urothelial carcinoma (HGUC) but less so for low‐grade urothelial neoplasm (LGUN). There is significant interobserver and interinstitutional variability, especially for the atypical category. The Paris system for reporting urinary cytology (TPS) was introduced to better define the various categories, especially atypical cytology. Methods We retrospectively reviewed 630 atypia of undetermined significance (AUS) cases and reclassified them based on TPS. In total, 501 cases previously reported as negative for malignancy had their medical records reviewed to serve as negative controls. Results Of 630 AUS cases, 299 (47.5%) were reclassified as negative for HGUC (NHGUC), 313 (49.7%) as atypical urothelial cells (AUCs) and 18 (2.9%) as suspicious for HGUC (SHGUC). Based on our institution's previous reporting system, the rate of underlying or subsequent HGUC was 2.8% for AUS, and 0% for negative. When AUS cases were reclassified under TPS, the rates were 1.5% for NHGUC, 4.8% for AUC, and 0% for SHGUC. Review of medical records showed that patients with AUS were more likely to be followed‐up compared with those with negative urine cytology (77.8% compared with 54.3%), particularly those under the care of non‐urologists. Conclusions AUS diagnosis is associated with more patient follow up compared with NEG urine particularly among non‐urologists. Reclassifying according to TPS results in significant reduction in the rate of AUS and thus unnecessary testing. This reduction however may be at the expense of slightly decreased detection rate of HGUC.