Qap (Anatomical Pathology) 

QAP Peer Review

AP202
Case History: F/73 Right knee tumor
Intended diagnosis: Myxoid malignant fibrous histiocytoma. Contributed by:USK
Code Diagnosis Comment Score
anonymous Malignant myxoid tumour consistent with myxoid malignant fibrous histiocytoma (100%) Immunostains for desmin, actin, S100, CD31, CD34 to exclude specific differentiation.  100
anonymous Malignant myxoid tumour consistent with myxoid malignant fibrous histiocytoma (100%) nil  100
anonymous myxofibrosarcoma nil  100
anonymous Myxofibrosarcoma 100% Main differentiation is from myxoid liposarcoma. Immunostaining with S-100 protein will highlight lipoblasts, whereas in myxofibrosarcoma the pseudolipoblasts will not be stained.  100
anonymous Myxoid malignant fibrous histiocytoma 70% Inflammatory myxohyaline tumor 30% nil  70
anonymous Malignant myxoid sarcoma consistent with myxoid malignant fibrous histiocytoma. 100% For differential diagnosis, to sample more tissue and do immunostains to search for any line of differentiation eg. myxoid liposarcoma.  100
anonymous Myxoid sarcoma. (100%) Inflammatory myxohyaline tumor of the distal extremities with virocyte or Reed-Sternberg-like cells needs to be considered/excluded. Other DDx includes chondrosarcoma, etc. Suggest more sampling and correlate with imaging.  60
anonymous Right knee tumor - Myxofibrosarcoma (Myxoid MFH) 100% nil  100
anonymous Malignant myxoid tumour (100%), differential diagnosis includes low grade fibromyxoid tumour (90%) and myxoid malignant fibrous histiocytoma (10%) nil  60
anonymous Myxoid sarcomatous lesion 100% Differential diagnoses include Myxoid liposarcoma, Myxoid malignant fibrous histiocytoma  60
anonymous Malignant myxoid tumor: 1) Myxofibrosarcoma; 2) Myxoid Chondrosarcoma; 3) Myxoid Liposarcoma. Perform x-ray, special stains and IHC.  60
anonymous Myxofibrosarcoma 100% nil  100
anonymous Juxta-articular myxoma 60% Low-grade myxoid sarcoma 40% Further blocks and correlation with clinical/radiology findings Ki-67 to assess proliferation Immunostains cytokeratin to exclude myxoid synovial sarcoma  40
anonymous Myxoid sarcoma, favor myxoinflammatory fibroblastic sarcoma, less likely myxoid malignant fibrous histiocytoma nil  60
anonymous Myxofibrosarcoma, intermediate grade nil  100
anonymous Myxofibrosarcoma. 100% Probability nil  100
anonymous Malignant myxoid tumour (100%); favour low grade myxoid malignant fibrous histiocytoma,(myxoid MFH)(90%); myxoid chondrosarcoma (10%) Examine more sections; immunostains for actin for myofibroblastic differentiation in myxoid MFH; S100 protein to exclude chondrosarcoma.  90
anonymous Low-grade myxofibrosarcoma. nil  100