Difficulties in diagnosing small round cell tumours of childhood from fine needle aspiration cytology samples

Abstract

There are four basic reasons for the difficulties in diagnosing small round cell tumours (SRCT) in childhood from fine needle aspiration cytology (FNAC) samples. First, SRCTs are rare and it is difficult for cytopathologists to obtain enough experience for rendering reliable diagnoses. Second, SRCTs are morphologically very similar. Third, many SRCTs do not have specific antigens which could be demonstrated with immunocytochemistry (ICC) or they lose them when poorly differentiated. In addition, cross reactivity exists between some SRCTs. Unstandardized performance of ICC also contributes to the difficulties due to unreliable results. Fourth, suboptimal FNAC samples add additional pitfalls. The latter may be due to partly degenerate samples or to unrepresentative ones in cases where a SRCT is a heterologous component of another nosological entity. Lymphoma, neuroblastoma, nephroblastoma, Ewing's tumour/primitive neuroendocrine tumours and rhabdomyosarcoma are discussed in detail, while other less common SRCTs are mentioned as differential diagnoses when appropriate. The use of cytogenetic and molecular techniques for differentiating between certain SRCTs is helpful in some doubtful cases. However, there are still problems in the use of these techniques, especially their cost which may delay their being introduced in every cytopathology laboratory.

Cytologic and Immunophenotypic Features of Malignant Cells in Pediatric Body Fluids

“…2). Cross-reactivity, suboptimal sampling, cellular degeneration and other similar factors have also been noted as causing difficulties in the diagnosis of small round cell tumors in a previous fine-needle aspiration study [20]. Some of the antibodies used in the differential diagnosis of pediatric small round cell tumors such as myoD1 and CD99 are known to yield nonspecific staining in surgical sections.…”

Evaluation of pediatric abdominal masses by fine‐needle aspiration cytology: A clinicoradiologic approach

“…[2][3][4][5][6][7] However, many a times FNA on a stand alone basis has certain limitations and lacks specific reproducible features to accurately subtype these tumors. [6][7][8][9] Nevertheless, if interpreted in conjunction with key clinical features and radiology, its utility can remarkably be enhanced to give a clinically meaningful diagnosis. [10][11][12][13][14] With this in mind, we decided to evaluate FNAC of all pediatric intra-abdominal masses accessioned over a period of 5 years in a referral cancer hospital, assess its utility in conjunction with key clinicoradiologic inputs, and compare the results with histopathology that was considered as the gold standard.…”

Successful Treatment of Adult Pleomorphic Rhabdomyosarcoma in the Posterior Left Femur: A Case Report

“…For diagnosis we need an adequate amount of tissue samples for routine light microscopy, immunohistochemistry, cytogenetics, and molecular genetic studies. These samples should be obtained at the time of biopsy or initial resection [11]. Separate categories have been established for "sarcoma, not otherwise specified" (NOS) tumors that could not be classified into a specific subtype, and for diffusely anaplastic sarcomas, which were previously included as pleomorphic sarcomas in older classifications and associated with a poor prognosis [10].…”