ABSTRACT
Fibroblastic/myofibroblastic tumors, benign 969 Atypical decubital fibroplasia 969 Calcifying fibrous tumor (pseudotumor) 969 Dermatomyofibroma 970 Desmoplastic fibroblastoma (collagenous fibroma) 970 Elastofibroma 971 Fibroma of tendon sheath 972 Fibroma, nuchal 972 Fibromatosis colli (congenital torticollis,
sternocleidomastoid tumor) 973 Fibromatosis, infantile digital 973 Fibromatosis, juvenile hyaline (fibromatosis hyalinica
multiplex; systemic hyalinosis) 973 Fibromatosis ‘knuckle pads’/pachydermodactyly 973 Fibrous hamartoma of infancy 974 Giant cell angiofibroma 974 Infantile myofibromatosis and solitary myofibroma in adults 975 Myofibroblastoma, intranodal 976 Myofibroblastoma, mammary-type 976 Myositis ossificans 976 Nodular fasciitis 977 Proliferative fasciitis 979 Proliferative myositis 979 Pyogenic granuloma 980 Retroperitoneal fibrosis 980 Sclerosing encapsulating peritonitis 981 Sclerosing mesenteritis (idiopathic retractile mesenteritis) 981 Solitary fibrous tumor (SFT) 982
Fibroblastic/myofibroblastic tumors, intermediate 983 Acral myxoinflammatory fibroblastic sarcoma
(inflammatory myxohyaline tumor) 983 Angiofibroma, juvenile nasopharyngeal 985 Fibromatosis 985 Fibromatosis, juvenile/infantile 987 Fibromatosis, palmar (Dupuytren’s disease/contracture) 987 Fibromatosis, penile (Peyronie’s disease) 987 Fibromatosis, plantar (Ledderhose disease) 987 Inflammatory myofibroblastic tumor (inflammatory
pseudotumor) 988 Lipofibromatosis 989
Fibroblastic/myofibroblastic tumors, malignant 990 Fibrosarcoma 990 Inflammatory fibrosarcoma of the mesentery and
retroperitoneum 990 Hyalinizing spindle cell tumor with giant rosettes (HSTGR) 991 Low-grade fibromyxoid sarcoma 991 Myofibrosarcoma 993 Myxofibrosarcoma (myxoid malignant fibrous histiocytoma) 994
Fibrohistiocytic tumors, benign 995 Fibrous histiocytoma 995 Juvenile xanthogranuloma 995
Reticulohistiocytic granuloma 995 Xanthoma 995
Fibrohistiocytic tumors, intermediate 995 Dermatofibrosarcoma protuberans (DFSP) 995
Bednar tumor (pigmented dermatofibrosarcoma protuberans) 995
Giant cell fibroblastoma 996 Plexiform fibrohistiocytic tumor 997
Fibrohistiocytic tumors, malignant 997 Malignant fibrous histiocytoma, angiomatoid 998 Malignant fibrous histiocytoma, giant cell type
(malignant giant cell tumor of soft parts) 999 Malignant fibrous histiocytoma, inflammatory type 1000 Malignant fibrous histiocytoma, pleomorphic
(storiform-pleomorphic MFH) 1000
Lipocytic tumors, benign 1001 Angiolipoma 1001 Chondroid lipoma 1002 Dendritic fibromyxolipoma 1003 Hibernoma 1003 Intramuscular lipoma 1004 Lipoblastomatosis and benign lipoblastoma 1004 Pleomorphic lipoma 1005 Sclerotic lipoma 1005 Spindle cell lipoma 1006
Lipocytic tumors, malignant 1008 Liposarcomas 1008
Lymphatic tumors 1012 Benign lymphangioendothelioma (acquired progressive
lymphangioma) 1012 Lymphangioleiomyomatosis (lymphangiomyomatosis) 1012 Lymphangiomas 1013 Lymphangiomyoma 1013
Lymphoreticular tumors 1013 Extramedullary hematopoiesis/hemopoietic tumor 1013 Follicular dendritic cell sarcoma 1014 Granulocytic sarcoma 1014 Interdigitating cell sarcoma 1015 Rosai-Dorfman disease 1015
Peripheral nerve sheath tumors, benign 1015 Fibrolipomatous hamartoma of nerve 1015 Morton’s neuroma 1016 Neurofibroma, solitary 1016 Neurofibromatosis (von Recklinghausen’s disease) 1016 Neuroma, Pacinian 1018 Neuroma, solitary circumscribed 1018 Neuroma, traumatic 1019
Perineuroma (storiform perineurial fibroma) 1020 Schwannoma (neurilemmoma) 1021 Triton tumor, benign (neuromuscular
hamartoma/choriostoma) 1024
Peripheral nerve sheath tumors, malignant 1025 Malignant peripheral nerve sheath tumor (MPNST) 1025 Triton tumor, malignant 1028
Peripheral neuroectodermal tumors 1029 Malignant ectomesenchymoma 1029 Myxopapillary, extraspinal or soft tissue ependymoma 1029 Neuroblastoma, olfactory (esthesioneuroblastoma) 1031 Neuroblastomas 1031 Paragangliomas 1031
Gangliocytic paraganglioma 1031 Pigmented neuroectodermal tumor of infancy
(melanotic progonoma, retinal anlage tumor) 1033
Perivascular tumors 1034 Hemangiopericytoma 1034 Lipomatous hemangiopericytoma 1034 Perivascular epithelioid cell tumor (‘PEComa’) 1035 Perivascular myoid tumors 1036
Skeletal muscle tumors, benign 1037 Rhabdomyomas 1037 Rhabdomyoma, fetal 1037 Rhabdomyoma, genital 1038 Rhabdomyoma, adult type 1038 Rhabdomyoma, cardiac type 1038
Skeletal muscle tumors, malignant 1039 Rhabdomyosarcomas 1039 Rhabdomyosarcoma, alveolar 1039 Rhabdomyosarcoma, embryonal 1040 Rhabdomyosarcoma, embryonal ‘botryoid variant’ 1042 Rhabdomyosarcoma, embryonal ‘spindle cell variant’ 1042 Rhabdomyosarcoma, pleomorphic 1043 Rhabdomyosarcoma, sclerosing, pseudovascular 1043
Smooth muscle tumors, benign 1044 Leiomyoma, extrauterine 1044 Myolipoma (lipoleiomyoma) of soft tissue 1046
Smooth muscle tumors, malignant 1046 Leiomyosarcomas, extrauterine 1046
Soft tissue tumors, cartilage-and bone-forming, benign 1050 Calcifying aponeurotic fibroma 1050 Extraskeletal chondromas 1051 Myositis ossificans 1052 Synovial chondromatosis 1052
Soft tissue tumors, cartilage-and bone-forming, malignant 1053 Ectomesenchymal chondromyxoid tumor of the tongue 1053 Extraskeletal mesenchymal chondrosarcoma 1053 Extraskeletal myxoid chondrosarcoma 1054 Phosphaturic mesenchymal tumor 1055 Tenosynovial giant cell tumors (TGCTs) 1057
Soft tissue tumors, miscellaneous 1059 Acellular deposits 1059
Amyloid tumor 1059
Gout tophi 1059 Polyvinyl pyrrolidone granuloma 1060 Tumoral calcinosis 1060
Extragonadal germ cell tumors (GCTs) 1061 Extrarenal rhabdoid tumors 1061 Ganglion cyst 1062 Ganglioneuroblastoma 1063 Ganglioneuroma 1063 Gastrointestinal stromal tumor (GIST) 1064 Myoepithelioma of soft tissue 1066 Radiation-associated sarcomas 1067
Soft tissue tumors, uncertain differentiation 1067 Aggressive angiomyxoma 1067 Alveolar soft part sarcoma 1067 Clear cell sarcoma of tendon sheath 1068 Desmoplastic small round cell tumor 1069 Epithelioid sarcoma 1070 Ewing’s sarcoma/primitive neuroectodermal tumor
(PNET)/small cell tumor of thoracopulmonary origin (Askin’s tumor) 1072
Granular cell tumor 1073 Malignant mesenchymoma 1074 Myxomas 1075
Low-grade myxoid neoplasm with recurrent potential (cellular myxoma) 1075
Myxoma, cardiac 1075 Myxoma, intramuscular 1076 Myxoma, juxta-articular 1077
Ossifying fibromyxoid tumor of soft parts 1077 Parachordoma 1078 Pleomorphic hyalinizing angiectatic tumor 1079 Superficial acral fibromyxoma 1079 Superficial angiomyxoma 1080 Synovial sarcoma 1081
Vascular tumors, benign 1084 Angioendotheliomatosis, benign, reactive 1084 Benign vascular proliferation in irradiated skin 1084 Epithelioid angiomatosis (bacillary angiomatosis) 1085 Hemangioma, capillary 1085 Hemangioma, cavernous 1087 Hemangioma, epithelioid (angiolymphoid hyperplasia
with eosinophilia) and Kimura’s disease 1087 Hemangioma, intramuscular 1089 Hemangioma, intravascular papillary endothelial
hyperplasia/Masson’s vegetant hemangioendothelioma/Masson’s hemangioma 1090
Hemangioma, microvenular 1091 Hemangioma, sinusoidal 1091 Hemangioma, synovial 1091 Hemangioma: spindle cell hemangioma/
hemangioendothelioma 1091 Hemangioma: targetoid hemosiderotic hemangioma/
hobnail hemangioma 1092 Littoral cell angioma, spleen 1092 Vascular malformations 1092 Vascular malformations, venous hemangioma
(venous malformation) 1093 Vascular malformations, verrucous hemangioma/
There is a wide variety of soft tissue tumors, the majority of which are benign. Malignant soft tissue tumors are relatively uncommon and are seen mainly in the extremities, trunk and within the abdomen, especially in retroperitoneal space. Soft tissue tumors also occur within the mesenchyme of visceral organs. Among the commonly encountered soft tissue tumors, there are limited numbers of morphological patterns and subpatterns that are identified (for details, see Chapter 1, Histological patterns). Some patterns are shared by both benign and malignant tumors. Recognizing these histological prototypes would limit the number of lesions within the differential diagnostic list. Knowledge of the anatomical location would further reduce the diagnostic possibilities.
