Extraskeletal myxoid chondrosarcoma
Clinical features Fig 26 – Extraskeletal myxoid chondrosarcoma – Single cells or cells in small isolated groups or matrix embedded aggregates. Long delicate spicules of this matrix, with sharply defined edges, blend with the myxoid background (H&E). Histochemical Stains Immunocytochemistry Electron microscopy Genetic studies Differential Diagnosis Main points
Myxoid liposarcoma
Clinical features Fig 22 – Myxoid liposarcoma –Myxoid stroma with plexiform capillary network (Giemsa) Histochemical Stains Immunocytochemistry Genetic Studies Differential Diagnosis Main points
Lipoblastoma
Clinical features Fig 18a (H&E), Lipoblastoma – Fragments of adipose tissue, (mixture of fat cells in different stages of maturation) (H&E) Genetic Studies Differential Diagnosis Numerous paediatric lesions can have adipose tissue within: Main points Surgery is the treatment of choice
Nodular fasciitis
For more details see “spindle cell lesions”
MIXOID LESIONS
III – SOFT TISSUE TUMORS OTHER THAN RHABDOMYOSARCOMA
GENERAL CONSIDERATIONS Malignant soft tissue tumours are unusual in adolescents and children. We will only address to those which are more specific or characteristic of this age group. Children with sarcomas, (especially under 2 years) have 7% to 33% of genetic predisposition to cancer in general Fine needle biopsy (FNA) of soft tissue lesions is […]
II – RHABDOMYOSARCOMA
Clinical features Fig 13a – Alveolar rhabdomyosarcoma – Cellular smears with a background with apoptotic bodies and loosely cohesive aggregates of uniform, small round blue cells (H&E). Fig 14a– Alveolar rhabdomyosarcoma – Giemsa- remark the typical tigroid background Fig 16 a- Embryonal rhabdomyosarcoma- Nuclei can have pseudo inclusions (H&E) Immunocytochemistry Genetic studies Differential diagnosis […]
Metanephric Adenoma
Clinical features Fig 12a – Metanephric adenoma- Monomorphous small blue cell population in a clean background forming small tubules or rosettes.(H&E), Cells have round or oval nuclei show no atypia and a minimum amount of cytoplasm. Immunocytochemistry Genetic studies Differential Diagnosis Main Points
Renal cell carcinoma (RCC)
Clinical features Fig 10 a – Renal cell carcinoma- abundant clear micro vacuolated cytoplasm with ill-defined borders and macrophages with hemosiderin pigment, Immunocytochemistry Genetic studies Contrary to what is observed in adults, childhood RCC is less frequently associated with mutations and deletion of the VHL genes Differential diagnosis Main points
Renal primitive neuroectodermal tumour-Ewing Family Tumour
Clinical features Cytopathology (similar to Ewing Family tumours (EFT) elsewhere) Classical: Immunocytochemistry Genetic studies: Differential diagnosis Main points Molecular demonstration of t(11;22)(q24;q12) is sometimes essential, to distinguish from Wilms’ tumour