DOG1 - GIST (membranous, cytoplasmic), normal pancreas (islets), associated with BRCA1.BCL2 - synovial sarcoma, small cell lymphomas, spindle cell lipoma, solitary fibrous tumour.Fletcher useful if membranous stain pattern = Ewing sarcoma/PNET. CD99 - immature T cells (thymus), small round cell tumours, synovial sarcoma, Merkel cell carcinoma, osteosarcoma.S-100 - neural marker, sensitive for malignant melanoma, Langerhans cells, clear cell sarcoma.CD34 - GIST, angiosarcoma, solitary fibrous tumour/ hemangiopericytoma, Kaposi sarcoma, DFSP, PASH.Memory device SCADS or CAD SS = S-100, CD34, AE1/AE3, Desmin, SMA. Grouping by pattern See: Basics#Morphologic patterns. Others - see pleomorphic tumours for an exhaustive DDx.Pleomorphic - large variation of tumour cell size.Monomorphic - small variation of tumour cell size.Sertoli cell tumour & granulosa cell tumour Mixed endometrial stromal and smooth muscle tumour of the uterus Skeletal muscle and neural differentiationĬongenital pseudarthosis associated with neurofibromatosis Ossifying desmoplastic nested epithelial-stromal tumour of liver Hyalinizing spindle cell tumour with giant rosettesĪnthracotic & anthracosilicotic spindle cell pseudotumour of mediastinal lymph node Ossifying fibromyxoid tumour of soft parts Superficial cervicovaginal myofibroblastoma Seen in chronic myeloproliferative disorders Īngiolymphoid hyperplasia with eosinophiliaĭiffuse-type tenosynovial giant cell tumourįasciitis-like reactive myofibroblastic proliferation Sclerosing extramedullary hematopoetic tumours Spindle epithelial tumor with thymus-like differentiation 1.1 A long differential diagnosis of spindle cell tumoursĪ long differential diagnosis of spindle cell tumoursĪdapted from Miller with modifications: TumourĪngiomyolipoma, lymphangioleiomyomatosis, other PEComas.

Spindle cells