summary Extra-abdominal Desmoid Tumors are benign, locally aggressive, fibrogenic lesions that are associated with familial adenomatous polyposis (FAP). The condition usually presents in patients between the ages of 25 and 35 with a firm, enlarging soft tissue mass Diagnosis is made with a biopsy showing well-differentiated fibroblasts with uniform spindle cells with elongated nuclei and occasional mitoses. Immunohistochemistry will show a positive stain for estrogen receptor-beta. Treatment may be medical management with tamoxifen or wide surgical excision with radiotherapy depending on the size, grade and location of the lesion. 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% Anatomic 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 Etiology 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 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 tumors may remain stable and regress observation compares favorably with surgical management in some studies 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% recurernce with surgery + radiation Prognosis High risk of recurrence Highly unpredictable lesions Occasional spontaneous regression No risk of metastasis or malignant transformation, unless related to radiation
QUESTIONS 1 of 5 1 2 3 4 5 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ12.216) A 35-year-old female presents with an enlarging, painless âlumpâ 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? QID: 4576 FIGURES: A B C D E Type & Select Correct Answer 1 Figure A 25% (704/2840) 2 Figure B 18% (514/2840) 3 Figure C 21% (605/2840) 4 Figure D 10% (271/2840) 5 Figure E 25% (705/2840) L 5 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review Tested Concept Review Full Topic (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? QID: 3237 Type & Select Correct Answer 1 Desmoid tumor 82% (2489/3037) 2 Ewingâs sarcoma 2% (71/3037) 3 Synovial sarcoma 3% (95/3037) 4 Multiple myeloma 9% (259/3037) 5 Giant cell tumor 3% (101/3037) L 2 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review Tested Concept Review Full Topic (OBQ09.258) Which inherited condition shows a strong association with extra-abdominal desmoid tumors? QID: 3071 Type & Select Correct Answer 1 Familial adenomatous polyposis 63% (1055/1670) 2 Sinding-Larsen-Johansson syndrome 8% (131/1670) 3 Ollier's disease 8% (129/1670) 4 Fanconi anemia 5% (80/1670) 5 McCune-Albright syndrome 16% (273/1670) L 3 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review Tested Concept Review Full Topic (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? QID: 3038 FIGURES: A B C D Type & Select Correct Answer 1 Osteosarcoma 1% (37/3079) 2 Leiomyosarcoma 26% (797/3079) 3 Extraabdominal fibromatoses (desmoid tumor) 68% (2108/3079) 4 Angiosarcoma 3% (105/3079) 5 Chondroblastoma 0% (14/3079) L 2 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review Tested Concept Review Full Topic
All Videos (0) Podcasts (1) PathologyâȘExtra-abdominal Desmoid Tumor Orthobullets Team Pathology - Extra-abdominal Desmoid Tumor Listen Now 11:41 min 6/16/2020 65 plays 4.0 (1)