Introduction A fibrogenic lesion that is the most locally invasive of all benign soft tissue tumors Epidemiology incidence 900 cases a year in US demographics younger individuals (25-35 years of age) female>male (3:1) higher incidence in familial adenomatous polyposis (FAP) and Gardner syndrome 4-30% location most common shoulder (20%) > chest wall/back (17%) > thigh (13%) >50% are extra-abdominal may have multiple lesions in the same extremity subsequent mass usually appears more proximally in the same limb appears in sites of previous surgery or scars Genetics patient's with familial adenomatous polyposis (FAP) have increased risk for development of desmoid tumors 15% of tumors have adenomatous polyposis coli (APC) gene mutation (gene controls beta catenin) elevated levels of beta catenin in all tumors trisomy in chromosome 8 or 20 Associated conditions Dupuytren contractures Ledderhose disease familial adenomatous polyposis (FAP) Gardner syndrome Prognosis high risk of recurrence highly unpredictable lesions occasional spontaneous regression no risk of metastasis or malignant transformation, unless related to radiation Symptoms Presentation usually an enlarging mass nerve compression numbness, tingling, motor weakness, stabbing pain Physical exam has a distinctive "rock hard" feel on palpation because tumor is fixed to surrounding tissues poorly circumscribed may be painful and limit motion around joint Imaging Radiographs play minimal role in diagnosis some tumors encroach on/erode bone or trigger periosteal reaction that extends into tumor as "frond like" spicules of bone MRI Indications best means to diagnose exclude multicentric lesions (in the same extremity) findings low signal intensity on T1-weighted images low to medium intensity on T2-weighted images Gadolinium enhances appearance infiltrates muscle 5-10cm in size may erode bone locally Studies Gross specimen gritty white poorly encapsulated Histology Classic characteristics are well differentiated fibroblasts uniform spindle cells with elongated nuclei and occasional mitoses abundant collagen tumor infiltrates adjacent tissues Molecular Genetics/Immunohistochemisty positive 100% positive for estrogen receptor-beta somatostatin cathepsin D Ki-67 c-Kit negative estrogen receptor-alpha progesterone receptor HER2 Treatment Nonoperative low dose-chemotherapy only / tamoxifen indications inoperable lesions tamoxifen favored for failed/poor candidates for standard chemotherapy works because most lesions occur in women and are more aggressive in women, especially premenopausal tamoxifen works via an estrogen receptor blockage Operative wide surgical resection with radiotherapy indications symptomatic lesion recurrent lesion local recurrence is common (reduced recurrence with radiotherapy) external beam radiation dose 50-60Gy Complications Recurrence margin negative 28% recurrence with surgery alone 6% recurence with surgery + radiation margin positive 39% recurence with surgery alone 25% recurrnce with surgery + radiation IBank Location Xray Xray CT B. Scan MRI MRI Histo(1) Case A tibia (1) - histology does not always correspond to case
QUESTIONS 1 of 4 1 2 3 4 Previous Next (OBQ10.149) Estrogen receptor blockade has been moderately successful treating which of the following tumors, while reducing the morbidity of side-effects associated with previous treatments? Review Topic QID: 3237 1 Desmoid tumor 80% (1355/1689) 2 Ewing’s sarcoma 3% (47/1689) 3 Synovial sarcoma 3% (49/1689) 4 Multiple myeloma 11% (189/1689) 5 Giant cell tumor 2% (40/1689) ML 2 Select Answer to see Preferred Response PREFERRED RESPONSE 1 (OBQ09.258) Which inherited condition shows a strong association with extra-abdominal desmoid tumors? Review Topic QID: 3071 1 Familial adenomatous polyposis 62% (810/1317) 2 Sinding-Larsen-Johansson syndrome 9% (114/1317) 3 Ollier's disease 8% (100/1317) 4 Fanconi anemia 5% (67/1317) 5 McCune-Albright syndrome 17% (226/1317) ML 3 Select Answer to see Preferred Response PREFERRED RESPONSE 1 (OBQ12.216) A 35-year-old female presents with an enlarging, painless “lump” on her left posterior shoulder. She denies weakness or paresthesias of her left upper extremity. Her maternal uncle, mother, brother, and herself have a history of multiple colonic polyps, jaw osteomas and epidermoid cysts. She ultimately undergoes biopsy of the mass. Which of the following is most likely to be consistent with the histology of the biopsy specimen? Review Topic QID: 4576 FIGURES: A B C D E 1 Figure A 26% (579/2208) 2 Figure B 17% (381/2208) 3 Figure C 21% (461/2208) 4 Figure D 9% (195/2208) 5 Figure E 25% (558/2208) ML 5 Select Answer to see Preferred Response PREFERRED RESPONSE 2 (OBQ09.225) A 20-year-old female presents with a "rock-hard" mass in the calf shown in Figure A. MRI, gross pathology, and histology images are shown in Figure B-D, respectively. Immunohistochemical studies of the mass were strongly positive for Estrogen receptor-beta expression. What is the most likely diagnosis? Review Topic QID: 3038 FIGURES: A B C D 1 Osteosarcoma 1% (28/2323) 2 Leiomyosarcoma 26% (597/2323) 3 Extraabdominal fibromatoses (desmoid tumor) 68% (1589/2323) 4 Angiosarcoma 4% (86/2323) 5 Chondroblastoma 0% (9/2323) ML 2 Select Answer to see Preferred Response PREFERRED RESPONSE 3