Fine needle aspiration cytology of paediatric soft tissue tumours highlighting challenges in diagnosis of benign lesions and unusual malignant tumours

Abstract

Introduction The type of soft tissue lesions seen in children differs from that seen in adults. The role of fine needle aspiration (FNA) cytology in their diagnosis is not well documented. Aim To study the cytopathological spectrum of paediatric soft tissue tumours to highlight uncommon benign and malignant lesions and the challenges in their diagnosis. Methods A 3‐year retrospective audit of all paediatric soft tissue FNA cytology cases from 2015 to 2017 was performed. Smears were reviewed along with cell block immunocytochemistry and follow‐up histopathology of resected specimens wherever available. Results A total of 127 cases were reviewed, which included 72 benign and 55 malignant soft tissue tumours. Uncommon lesions described herein are myxoid fibrohistiocytic tumour, myxoma, lipoblastoma, Bednar tumour, malignant extra‐renal rhabdoid tumour and desmoplastic small round cell tumour. Histopathology confirmation was available in 25 cases, out of which 16 cases were completely concordant. In eight cases, all benign diagnoses, histopathology provided more accurate subtyping than FNA. These included cases of lipoblastoma, myxoma and spindle cell haemangioma. Conclusion FNA cytology of paediatric soft tissue tumours is accurate in classifying lesions as benign or malignant which helps in treatment planning. Immunocytochemistry performed on cell blocks is useful for subtyping malignant lesions.

Lipoblastoma de extremidades y tronco: recurrencia local y complicaciones después de la resección marginal. Estudio multicéntrico

“…Sin embargo, las biopsias por punción pueden servir como una herramienta útil en el diagnóstico preoperatorio del lipoblastoma 16,17 y pueden realizarse con anestesia mínima. Para los patólogos es más dificultoso identificar y clasificar, de manera segura, las lesiones de partes blandas por el material obtenido en una biopsia por punción (especialmente en una punción con aguja fina), pero esto se puede realizar con bastante seguridad.…”

“…Para los patólogos es más dificultoso identificar y clasificar, de manera segura, las lesiones de partes blandas por el material obtenido en una biopsia por punción (especialmente en una punción con aguja fina), pero esto se puede realizar con bastante seguridad. 17 La edad de presentación, el examen histopatológico y los marcadores cromosómicos son los tres factores que ayudan a llegar al diagnóstico patológico final.…”

Fine‐needle aspiration cytology in soft tissue tumors—5‐year institutional experience

“…Difficulties are seen in accurately subtyping the tumors according to cell of origin, separating benign lesions from low grade sarcomas as well as correctly subclassifying the sarcoma. [21][22][23] Review of the cases with discordant diagnosis demonstrates some of the pitfalls which makes cytological diagnosis challenging. Few of these cases are briefly discussed in Table 5.…”

“…Larger studies have shown that category of spindle cell lesions is the most challenging to diagnose. Difficulties are seen in accurately subtyping the tumors according to cell of origin, separating benign lesions from low grade sarcomas as well as correctly subclassifying the sarcoma 21–23 . Review of the cases with discordant diagnosis demonstrates some of the pitfalls which makes cytological diagnosis challenging.…”

Juxta-articular Myxoma of the Hip: A Rare Pediatric Tumor

“…In our case, as like as in previously reported 5-year-old boy case, biopsy was inefficacious because of collection of nonrepresentative tissue. Recently, Agrawal et al 14 reported fine needle aspiration citology of pediatric soft-tissue lesions and neoplasms as a first-line investigation. Anyway, in his study, histopathology provided more accurate subtyping than fine needle aspiration in 8/25 cases, all benign diagnoses as myxoma and lipoblastoma.…”