Practical morphological approach to the diagnosis and differential diagnosis of soft tissue sarcomas

Tumor Desmoplásico de Pequenas Células Redondas: Relato de Caso

“…Como o TDPCR, o sarcoma de Ewing/PNET é composto de pequenas células redondas em ninhos ou folhas. Entretanto, na imuno-histoquímica, o sarcoma de Ewing/ PNET é tipicamente positivo para MIC2 (CD99) e vimentina, mas negativo para citoqueratinas e marcadores miogênicos 16,17 . O neuroblastoma e o tumor de Wilms também compartilham muitas características morfológicas com TDPCR, mas ocorrem em crianças muito jovens e citogeneticamente falta a translocação 13 .…”

Fine needle aspiration and core biopsy from a 43‐year‐old man with multiple abdominal masses

“…DSRCT must be distinguished from other small round cell tumours, such as Ewing's sarcoma/primitive neuroectodermal tumour (PNET), small cell carcinoma, lymphoma, neuroblastoma, Wilms tumour, rhabdomyosarcoma and malignant mesothelioma 7,8 . For instance, cytological material aspirated from Ewing's sarcoma/PNET may contain small round cells arranged singly and in small clusters.…”

“…Aspirates from high‐grade lymphoma may display cytological features similar to DSRCT, but lymphomas do not exhibit the cohesion and nuclear features of DSRCT 7,8 . Furthermore, immunostains would help with the distinction between the two entities by showing reactivity of lymphoma cells to lymphoid markers and negativity to epithelial, neuroendocrine and muscular markers.…”

“…However, nuclear moulding is not characteristic of rhabdomyosarcoma. Immunohistochemically, rhabdomyosarcoma is positive for muscle markers including desmin, actin and myogenin, but usually is negative for cytokeratins, S‐100 protein and neural markers 7,8 . Neuroblastoma and Wilms tumour also share many cytological features with DSRCT, but it occurs in very young children.…”