The MRI Findings of Collagenous FibromaDesmoplastic Fibroblastoma Ar - PDF document

The MRI Findings of Collagenous Fibroma(Desmoplastic Fibroblastoma) Arising in the, Wantae Kim, Yoonjung Kim CASE REPORT www.ksmrm.org avascular soft tissue mass located in the deep site ofsupraspinatus tendon and muscle. The differentialdiagnosis on US was fibromatous tumor or pigmentedvillonodular synovitis on shoulder joint. Weperformed MR imaging by using a 1.5 Tesla magnetMR unit (Signa HD, GE Medical system, Milkwaukee,WI, USA) to characterize the internal architecture andfound well-marginated mass under the supraspinatusmuscle and tendon extending to the spinoglenoidnotch and joint capsule. This mass presents slightlyindentation on the supraspinatus muscle and tendon.On T1-weighted MR images, the mass showedinhomogenous intermediate and hypointense signalintensity to muscle (Fig. 1a). On T2-weighted MRimages, the mass showed hypointense signal intensityto muscle (Fig. 1b, c). On gadolinium-enhanced T1-weighted images, the majority of this lesion revealedno significant enhancement (Fig. 1d). US guided gunbiopsy was performed. Microscopically, the tumor wascomposed stellate-shaped fibroblastic cells distributedin abundant collagen component (Fig. 1e). Thecellularity was very low. Sarcomatous component wasabsent. Immunohistochemically, the tumor cellsshowed positive reactivity for vimentin. The tumor Axial fat suppressed T2-weighted MR image shows heterogenous hypointensity to muscle with partial infiltration to supraspinatCoronal fat suppressed T1-weight MR image after gadolinium administration shows no significant enhancement in the leftPhotomicrograph of the histopathologic specimen shows scattered stellate-shaped fibroblasts in abundant collagenous matrix (H  was negative for smooth muscle actin (SMA), desmin,epithelial membrane antigen (EMA), S-100 protein,CD34 and CK (AE1/AE3). The origi

nal diagnosis ofthis tumor was collagenous fibroma. The patient hadnot treated with surgical resection. Collagenous fibroma (desmoplastic fibroblastoma) isa benign fibrous soft tissue tumor with distinct clinico-pathologic features (46). These tumors show predilec-tion for male patients (5:1) and have a peak inciden-cein the fifth and sixth decades of life. The lesion hasbeen reported in the arm (24%), shoulder (19%),posterior neck or upper back (14%), abdominal walland hip joints (6%) (5, 6). Most tumors were locatedin the subcutaneous tissue or in skeletal muscle sameas our case (1, 10). Clinically, the lesion is characteris-tic slowly growing, painless mass that has increased insize for over a year in approximately one-third of case(6). Collagenous fibroma typically infiltrates subcuta-neous fat and skeletal muscle, and this has beenobserved in up to 51% of cases (6). To our knowledge,presentation with ongoing pain or neurologic deficit israre feature, despite nerve entrapment. Miettinen andFetsch (6) have described nerve entrapment onhistological finding in up to one-third of cases withoutany neurologic symptoms. Fong F, et al. (3) hasreported a case with neurological symptom combinedprevious trauma history and described that precedingtrauma may induce pain. Particularly in the shoulderarea, rotator cuff impingement or joint instability mayrarely result from the specific location of the tumoraround rotator cuffs or bursal spaces (7). In our case,the patient presented night pain without anyneurologic deficit and that is due to tumor infiltrationinto supraspinatus muscle and tendon. Histologically, the lesion consists of stellate- andspindle shaped fibroblastic cells sparsely distributed incollagenous and fibromyxoid matrix (1is very low and mitotic figures are absent (4According to Miettinen and Fet

sch (6), its hypocelluar-ity represents a benign neoplasm or persistent reactiveprocess. A few case reports describe the MRI features of thistumor (1, 2, 8, 10). On MRI, the lesion shows a masswith low signal on both T1- and T2-weighted images.Gadolinium-enhanced T1-weighted images shows non-enhancing areas within the mass. The areas of lowsignal intensity on both T2- and contrast enhanced T1-weighted images correspond with a hypocellularcomponent with abundant collagen fiber (1, 2, 8, 10).In a soft-tissue tumor, decreased signal on T2-weighted pulse sequence is attributed to abundantcollagen and marked hypocellularity. Soft-tissuetumors with low signal intensity on T2-weightedimages include neurofibroma, cicatricial fibroma,malignant fibrous histiocytoma, aggressive fibromato-sis, calcified lesions (myositis ossificans, extraskeletalosteosarcoma or chondrosarcoma, and synovialsarcoma) (2, 3). The radiological differential diagnoses includesnodular fasciitis, fibroma of the tendon sheath, neurofi-broma, calcifying fibrous pseudotumor, scleroticfibroma, desmoid tumor (extraabdominal fibromatosis),and other malignant neoplasm such as low gradefibromyxoid sarcoma (1, 2, 6, 10). The most importantdifferential diagnosis to be considered is desmoidtumor. The similarity in imaging findings betweencollagenous fibroma and desmoid tumor is because ofthe collagen content in both lesions. Desmoid tumor ismore cellular, more vascular and more infiltrative at itsperiphery than collagenous fibroma. On imaging study,desmoid tumor would not be clearly circumscribed andhave larger areas showing high signal intensity on T2-weighted image representing more cellularity thancollagenous fibroma (13, 10). Treatment of collage-nous fibroma is surgical resection (1local recurrence nor metastasis after resection hasoccurred, wher

ase the high local recurrence rate (2965%) of desmoids tumor has been reported (8). In conclusion, we report a case of a collagenousfibroma of the supraspinatus muscle presented with anight pain. Although it is a rare soft tissue tumor,collagenous fibroma should be included in the differ-ential diagnosis of low signal intensity soft tissue masson T2-weighted MR images.1.Marinelli M, Lupetti E, Gigante A, Mandolesi A, Bearzi I, de2.Walker KR, Bui-Mansfield LT, Gering SA, Ranlett RD. DISCUSSION 3.Fong F, Odell E, Simo R. Collagenous fibroma (desmoplastic4.Evans HL. Desmoplastic firoblastoma: a report of seven cases.5.Nielsen GP, O6.Miettinen M, Fetsch JF. Collagenous fibroma (desmoplastic7.Lydia K, Thomas D, Eyiyemi O. An unusual cause of subacro-8.Ogose A, Hotta T, Emura I, Higuchi T, Kusano N, Saito H.9.Beggs I, Salter DS, Dorfman HD. Synovial desmoplastic fibrob-10.Shuto R, Kiyosue H, Yuko H, Miyake H, Kawano K, Mori H.ᱣᙍᢼᢜ; 임지ឰ- (134.7:1* 서៳ᙋಏ동൘둔᫈동6.2- 서៳보Ṹ병៼ឹᓿ의᷄೜ ುೞᢿឥ፯생᷅൓៼성섬유᤾(ೃ᷉조직ᷰ성섬유ዂ세ᴭ᤾*; 증ᇞ보೏서៳보Ṹ병៼ឹᓿ의᷄೜서៳보Ṹ병៼병리೜൓៼성섬유᤾ೃ᷉조직ᷰ성섬유ዂ세ᴭ᤾᡼ၽጾᜭ성섬유성ឰ조직᤾ᜭᢎླᢎ병ᏽ᡼ླᜭ᷅᷌ᐜ᷄ᢽ위᭛의ᶻ᷃조직ᢎໆ೓ಿ൹ឥ서보ᱣ서서ẩᢜ라ྜጻᱣ성의៶직ᢎྜ᤾ോᇢໆᰰ້ླᓿឥ서ᢎ᤾ോྜಏ조ឹᓿዂ두ឥ서ᢼᙍṕಏ၍를보인ླᢎᢼᙍṕಏ၍ྜᶧᐜ᷅൓៼᥺배ೈ᷃의໓᡼세ᴭ᥺성ᐞ᡽፭ឹ᷃ྜಯᢎླᢼᢜ들᡼ᕻᷔ된០ᓿ의ᢾᇖᢎ᜾೏ᜭ성ឰ조직᤾ᜭឥ서ྜၽጾ임ᓿ᧟Ṷ인໾ಅ의ᱣ증᡽동፭᷅ುೞᢿឥ생඄൓៼성섬유᤾의증ᇞ를보೏᷃೏ᢜ᷅ླ࿅᷅ᢜං೚኿의೜᷄Ṫ지16;253.256(20