Soft Tissue Tumors 1 PDF

Soft Tissue Tumors - I Robbins &Cotran Pathologic Basis of Disease, 10th Edition Eds: Kumar, Abbas, Aster Robbins Basic Pathology, 11th Edition Eds: Vinay Kumar Abul K. Abbas Nelson Fausto , Richard N. Mitchell Soft Tissue Tumors nonepithelial tissue other than bone, cartilage, central nervous syste...

Soft Tissue Tumors - I Robbins &Cotran Pathologic Basis of Disease, 10th Edition Eds: Kumar, Abbas, Aster Robbins Basic Pathology, 11th Edition Eds: Vinay Kumar Abul K. Abbas Nelson Fausto , Richard N. Mitchell Soft Tissue Tumors nonepithelial tissue other than bone, cartilage, central nervous system, hematopoietic, and lymphoid tissues. classified based on lines of differentiation (fat, fibrous tissue, and neural or vascular) These tumors mostly arise from pluripotent mesenchymal stem cells and are not the result of malignant transformation of mature mesenchymal cells. less than 1% of all invasive malignancies. 2% of all cancer deaths. Lethal ! Tumors of Adipose Tissue Lipomas Liposarcoma Tumors and Tumor-Like Lesions of Fibrous Tissue Nodular fasciitis Fibromatoses Superficial fibromatoses Deep fibromatoses Fibrosarcoma Tumors of Skeletal Muscle Rhabdomyoma Rhabdomyosarcoma Tumors of Smooth Muscle Leiomyoma Smooth muscle tumors of uncertain malignant potential Leiomyosarcoma Vascular Tumors Hemangioma Lymphangioma Hemangioendothelioma Angiosarcoma Peripheral Nerve Tumors Neurofibroma Schwannoma Granular cell tumor Malignant peripheral nerve sheath tumor Tumors of Uncertain Histogenesis Synovial sarcoma Alveolar soft part sarcoma Epithelioid sarcoma Undifferentiated pleomorphic sarcoma Classification of soft tissue tumors continues to evolve as new molecular genetic abnormalities are identified Certain sarcomas tend to appear in certain age groups: rhabdomyosarcoma - childhood synovial sarcoma - young adulthood liposarcoma and pleomorphic undifferentiated sarcomas - elderly Ethiology: Kaposi sarcoma => the human herpesvirus 8 (HHV8) Genetic syndromes: neurofibromatosis type 1 : neurofibroma, malignant schwannoma Gardner syndrome: fibromatosis Li-Fraumeni syndrome: Soft tissue sarcomas Ethiology: Unlike tumors such as colorectal carcinomas, no recognized precursor lesions has been identified. The best guess is that the tumors arise from pluripotent mesenchymal stem cells. Simple karyotype (15%–20% of sarcomas): Euploid tumors with a single or limited number of chromosomal changes => diagnostic markers. Tumors with these features tend to have a monomorphic appearance microscopically. Examples: Ewing sarcoma, and synovial sarcoma, liposarcoma Oncogenic tumor-specific fusion proteins represent potential molecular targets for diagnosis and therapy. Complex karyotype (80%–85% of sarcomas): These tumors are usually aneuploid or polyploid Demonstrate multiple chromosomal gains and losses=>genomic instability. Examples include leiomyosarcoma and undifferentiated pleomorphic sarcoma. Such tumors are more common in adults and elderly. Tend to be microscopically pleomorphic. Prognosis - Diagnostic classification. - Grading -> How agressive tumor is - Staging: How widely spread tumor is. Prognosis Grading. Grading, usually on a scale of I to III, is based on three parameters: degree of differentiation number of mitoses the extent of necrosis Grading and Staging www.mypathologyreport.ca Prognosis Staging: TNM T ⼀ Primary Tumour Extremity and Superficial Trunk T1 Tumour 5 cm or less in greatest dimension T2 Tumour more than 5 cm but no more than 10 cm in greatest dimension T3 Tumour more than 10 cm but no more than 15 cm in greatest dimension T4 Tumour more than 15 cm in greatest dimension N ⼀ Regional Lymph Nodes NX Regional lymph nodes cannot be assessed NO No regional lymph node metastasis N1 Regional lymph node metastasis M ⼀ Distant Metastasis MO No distant metastasis M1 Distant metastasis Grading and Staging Therapy: Surgical excision (frequently limb-sparing), Large, High Grade: Irradiation and/ or Chemotherapy may be added Tumors of Adipose Tissue, benign Lipoma benign tumors of fat. the most common soft tissue tumors in adults.. Mobile, slowly enlarging, painless masses (angiolipomas can manifest with local pain). Complete excision usually is curative. Conventional lipomas (the most common subtype) are soft, yellow, wellencapsulated masses of mature adipocytes, no pleomorphism. Tumors of Adipose Tissue, malignant Liposarcoma Around sixth decade of life. Deep soft tissues or in the retroperitoneum. Histologic subtype (prognostic): well differentiateddedifereantiaed myxoid pleomorphic variants MDM2 arrest p53 cell cycle senescence apoptosis Tumors of Adipose Tissue Well differentiated Liposarcoma/atypical lipomatous tumor Malignant Fifth and sixth decades of life. Deep soft tissues of extremities or in the retroperitoneum. MDM2 gene amplification Total excision is sufficient for treatment lipoblasts Cytoplasmic lipid vacuoles that scallop the nucleus (recapitulating that of fetal fat cells) Tumors of Adipose Tissue Dedifferentiated liposarcoma Malignant Fifth and sixth decades of life. Deep soft tissues of extremities or in the retroperitoneum. MDM2 gene amplification Tumor has ability to metastate Myxoid Liposarcoma t(12;16) FUS-DDIT3 fusion- adipocyte maturation arrest. Deep soft tissue of extremities. A decade younger than WDLS t(12;16) FUS-DDIT3 fusion- adipocyte maturation arrest Cells indicative of fatty differentiation known as lipoblasts are present. (recapitulating fetal adipocytes).Cellular variants are called «round cell-high grade» variants and has a worse prognosis Pleomorphic Liposarcoma Tumor of Elderlies Worst prognosis No recurrent genetic alteration, complex chromosomal abnormalities lipoblasts are present and necessary to detect for diagnosis Surgical excision and Chemo-radiotherapy Fibrous Tumors and Tumor-Like Lesions Nodular Fasciitis Self-limited fibroblastic proliferation Neoplastic? Reactive? t(17;22) (translocations involving USP6 gene) Adults on the volar aspect of the forearm, the chest, or the back. Short history of a solitary, rapidly growing mass No recurrence NF like composition + bone formation: Myositis Ossificans Athletic adolescents and young Fibromatosis Infiltrative growth of fibroblasts Frequent Recurence. Locally aggressive, no metastasis Superficial fibromatoses superficial fascia palmar / plantar fibromatosis (Dupuytren contracture) and penile fibromatosis (Peyronie disease). More innocuous come to clinical attention earlier. Deep fibromatoses (desmoid tumors) Abdomen, abdominal wall and muscles of the trunk and extremities Multiple=> Gardner syndrom, (AD, colonic adenomatous polyps and osteomas).Mutations in the APC or β-catenin genes are present in a majority of these tumors. More often recur after excision. They often recur when incompletely removed. Wide resection! Fibromatoses are gray-white, firm to rubbery, poorly demarcated, infiltrative masses 1 to 15 cm in greatest dimension. Histology: Plump spindle cells (fibroblast/ myofibroblast) arranged in broad sweeping fascicles that penetrate the adjacent tissue Fibrosarcoma Malignant neoplasms composed of fibroblastic cells Usually adults, there is a more innocuous infantile form Deep tissues of the thigh, knee, and retroperitoneal area. They tend to grow slowly Often recur locally after excision (in more than 50% of cases) and can metastasize hematogenously (in greater than 25% of cases), usually to the lungs. Soft unencapsulated, infiltrative masses Differentiation=> from tumors that closely resemble fibromatoses, to densely packed lesions with spindle cells growing in a herringbone fashion. Comparison of Fibroblastic tumors