Qap (Anatomical Pathology) 

QAP Peer Review

AP111
Case History: F/68. Left thigh mass 5x4x5 cm
Intended diagnosis: Intramuscular myxoma. Contributed by:JKCC
Code Diagnosis Comment Score
anonymous Intramuscular myxoma (100%) Need more extensive sampling and immunohistochemical stains to exclude myxoid variant of other soft tissue tumours such as nerve sheath or smooth muscle tumours.  100
anonymous Intramuscular myxoma nil  100
anonymous Intramuscular myxoma. 100% nil  100
anonymous Soft tissue, left thigh : Low grade myxoid neoplasm with recurrent potential (90%) Other low grade myxoid tumours should also be cosidered, in particuar, low grade myxofibrosarcoma (10%). More blocks should be taken to see if there are areas with cytologic atypia for low grade myxofibrosarcoma or unusual histologic features for other low grade myxoid tumours. Immunohistochemical studies may be necessary if other low grade myxoid tumours are suspected.  100
anonymous intramuscular mxyoma (100%) nil  100
anonymous Intramuscular myxoma, 100% nil  100
anonymous Grade 1 low-grade myxofibrosarcoma. 100% nil  80
anonymous Intramuscular myxoma. 100% Sample more blocks and provided all of them show similar histologic features.  100
anonymous Soft tissue lesion, thigh - Myxoma 100% nil  100
anonymous Myxoid liposarcoma (100%) Additional blocks to look for possible round cell component and infiltrative margins.  20
anonymous intramuscular myxoma nil  100
anonymous myxoma, intramuscular 11100% nil  100
anonymous Consistent with myxoma 90% More blocks should be taken to exclude the possibility of low grade sarcoma with myxoid change due to sampling error. Also, immunohistochemical study for S100 protein should be performed to exclude a neural tumour with prominent myxoid change.  100
anonymous Left thigh soft tissue mas : Myxoid soft tissue tumour with no frank anaplasia. Differential diagnosis includes : 1. Benign (50%): Myxoid neurofibroma (S100 positive), neurothekeoma (S100 or EM A positive), myxoid nodular fasciitis (recent onset), intramuscular myxoma (slightly too cellular & vascular). 2. Malignant (50%) : Myxoid liposarcoma, or myxoid MFH, or MPNST. Investigation : Cut more sections to look for specific vascular pattern, cellular pleomorphism or lipoblasts, and do immunostudies.  55
anonymous Intramuscular myxoma 100% nil  100
anonymous Low-grade myxoid neoplasm. Probability : 100% Differential diagnosis includes low-grade myxoid neoplasm with recurrent potential, myxoid malignant peripheral nerve sheath tumor, low-grade fibromyxoid sarcoma, low-grade myxofibrosarcoma and myxoid leiomyosarcoma. Would examine more blocks and perform immunostain for S100, Desmin, SMA and CD34, EM for exact differentiation.  75
anonymous Intramuscular myxoma (100%) nil  100
anonymous Myxoid tumor favour low grade myxofibrosarcoma (80%) Differential diagnoses include intramuscular myxoma (20%) and other low grade myxoid tumor. Suggest sample more blocks and perform immunohistochemical staining including S-100 protein, smooth muscle actin and CD34.  85