Diagnostic accuracy and cytomorphological spectrum of Wilms tumour in fine needle aspiration biopsy cytology samples supplemented with cell blocks

Wilms Tumor: An Unexpected Diagnosis in Adult Patients

CONTEXT.—

Wilms tumor (WT) in adult patients is rare and has historically been a diagnostic and therapeutic conundrum, with limited data available in the literature.

OBJECTIVE.—

To provide detailed diagnostic features, molecular profiling, and patient outcomes in a multi-institutional cohort of adult WT patients.

DESIGN.—

We identified and retrospectively examined 4 adult WT cases.

RESULTS.—

Two patients presented with metastatic disease, and diagnoses were made on fine-needle aspiration of their renal masses. The aspirates included malignant primitive-appearing epithelioid cells forming tubular rosettes and necrosis, and cell blocks demonstrated triphasic histology. In the remaining 2 cases, patients presented with localized disease and received a diagnosis on resection, with both patients demonstrating an epithelial-predominant morphology. Tumor cells in all cases were patchy variable positive for PAX8 and WT1 immunohistochemistry. Next-generation sequencing identified alterations previously reported in pediatric WT in 3 of 4 cases, including mutations in ASXL1 (2 of 4), WT1 (1 of 4), and the TERT promoter (1 of 4), as well as 1q gains (1 of 4); 1 case showed no alterations. Three patients were treated with pediatric chemotherapy protocols; during follow-up (range, 26-60 months), 1 patient died of disease.

CONCLUSIONS.—

WT is an unexpected and difficult entity to diagnose in adults and should be considered when faced with a primitive-appearing renal or metastatic tumor. Molecular testing may help exclude other possibilities but may not be sensitive or specific because of the relatively large number of driver mutations reported in WT.

Wilms Tumor in India: A Systematic Review

Shyam SrinivasanBackground  Cure rates of childhood malignancies are inferior in India compared with upper-middle-income countries. There is paucity of quality data addressing outcome of childhood Wilms tumor (WT) from India. This systematic review was conducted to assess the disease trends, treatment strategies, and outcome indicators in WT across India. Materials and Methods  We conducted a systematic search of MEDLINE, Google Scholar, and SCOPUS database, and additionally screened International Society of Pediatric Oncology conference abstracts. Data concerning WT or nephroblastoma published from India were extracted. Results  A total of 17 studies containing 1,170 patients were included in this review. Ninety-four percent of the studies were published after the year 2010. Advanced stage (III and IV) disease was seen in 46% of included patients. In seven studies, patients underwent a pretreatment biopsy before commencement of therapy. A hybrid approach consisting of "surgery first" in a selected subset and "neo-adjuvant chemotherapy" in all others was the most common treatment strategy adopted in half of the studies. The overall survival ranged between 48 and 89%. Key prognostic factors influencing survival across studies included increased tumor volume, metastatic disease, and unfavorable histology. Nonrelapse mortality (2.7-8.5%) was noted to be high. Conclusion  Substantial proportion of children with WT from India present with advanced stages of the disease. Despite several limitations, the current systematic review showed a modest survival among Indian children with WT. Adopting strategies through collaboration to ensure early access to expert care along with involvement of social support team to improve compliance may further improve survival of WT in India.

How we approach paediatric renal tumour core needle biopsy in the setting of preoperative chemotherapy: A Review from the SIOP Renal Tumour Study Group

The International Society of Paediatric Oncology Renal Tumour Study Group (SIOP-RTSG) advocate treating children with Wilms tumour (WT) with preoperative chemotherapy, whereas the Renal Tumor Committee of the Children's Oncology Group (COG) advocates primary nephrectomy (without biopsy) when feasible. Successive SIOP-RTSG trial protocols recommended pretreatment biopsy of children with unilateral tumours only where there were features to suggest an increased probability of a non-WT requiring a change in management. The UK experience in the SIOP WT 2001 trial showed that an alternate approach of performing biopsies on all children with renal tumour masses to determine histology at diagnosis rarely changes management, and can result in misdiagnosis (particularly patients in the age range typical for WT). Although a more selective approach to biopsy has been routine practice in all other countries participating in SIOP-RTSG trials, there was variation between national groups. To address this variation and provide evidence-based recommendations for the indications and recommended approach to renal tumour biopsy within the SIOP paradigm, an international, multidisciplinary working group of SIOP-RTSG members was convened. We describe the resulting recommendations of this group, which are to be incorporated in the ongoing SIOP-RTSG UMBRELLA study.

Mitosis-Karyorrhexis Index evaluation by digital image visual analysis for application of International Neuroblastoma Pathology Classification in FNA biopsy

BACKGROUND

The Mitosis-Karyorrhexis Index (MKI) score is important in neuroblastoma evaluation and in the application of the International Neuroblastoma Pathology Classification (INPC). Currently, it is not standardized for smears. Hence, the aim of this study was to devise and validate methods for MKI evaluation in fine-needle aspiration biopsy (FNAB) of neuroblastoma.

METHODS

A total of 50 cases of neuroblastoma diagnosed by FNAB from January 2017 to December 2019 were retrieved, and detailed cytomorphological evaluations were performed. The MKI was evaluated, and the eyeball visual assessment score (EVAS) was compared with the digital image visual analysis score (DIVAS) on cytology smears and corresponding histology sections of cell blocks. The interobserver reproducibility and concordance were calculated. INPC subtyping into favorable and unfavorable groups was performed by the collation of age, MKI, and cytomorphology and was correlated to clinical outcomes.

RESULTS

Neuroblastoma was categorized as undifferentiated (22 of 50) or poorly differentiated (28 of 50) on cytomorphology. The overall concordance for the MKI by 3 observers was 86% (κ = 0.85), and this increased to 98% in the high MKI category. MKI evaluations on smears showed 96% concordance with cell block histology, and the EVAS was concordant with the DIVAS in 86% of the cases. Overall, the MKI was high in 39 cases, intermediate in 4 cases, and low in 7 cases. The INPC category was unfavorable in 90% (n = 45) and favorable in 10% (n = 5) and had significant correlations with outcomes (P = .029).

CONCLUSIONS

An MKI assessment on smears by digital image visual analysis is accurate, reproducible, and objective and should be incorporated into the routine reporting of neuroblastoma FNAB for diagnostic schemas as per the INPC.