Dumbbell-shaped mass posterior to the right femur, low signalintensity on T1-weighted images. At the cranial pole are nodular areas of increased signalintensity on T1-weighted images.
A female patient born in 1961 is referred to our department for follow-up of an extra-abdominal desmoid tumor at the popliteal fossa diagnosed in 1989. The MRI examination of the right thigh in 1996 showed a dumbbell-shaped mass posterior to the right femur with a low signalintensity on T1-weighted images. At the cranial and distal pole of the mass there are nodular areas of increased signal intensity on T1-weighted images and slightly increased signal intensity on T2-weighted images. These hyperintense nodules are presumed to be active desmoid. We repeated the MRI examination in 1997 and 1998, without obvious changes. The MRI examination performed in 1999 showed a tumor of 7,5 * 5,7 * 30,5 cm in size and an increase of the hyperintense nodules at the cranial pole. The MRI examination of 2000 and 2001 showed unchanged findings. The size of the tumor had become a cosmetic problem for this patient and she actually consulted for a non-surgical therapy of the desmoid tumor.
Fibromatoses are a broad group of benign fibrous tissue proliferations of similar microscopic appearence that are intermediate in their biological behavior between benign fibrous lesions and fibrosarcoma. Fibromatosis comprises: A) Superficial fibromatosis: 1) palmar fibromatosis = Dupuytren’s disease, 2) plantar fibromatosis = Ledderhose’s disease, 3) penile fibromatosis = Peyronie’s disease, 4) Knuckle pads, B) Deep fibromatosis: 1) extraabdominal fibromatosis = extraabdominal desmoid, 2) abdominal fibromatosis = abdominal desmoid, 3) intraabdominal fibromatosis = intraabdominal desmoid: i) pelvic fibromatosis, ii) mesenteric fibromatosis, iii) mesenteric fibromatosis in Gardner’s syndrome. Fibromatoses are characterized by their infiltrative growth, frequent recurrence, but they almost never metastasize. Deep fibromatoses are rapidly growing tumors that often attain a large size. They tend to be more aggressive in their behavior than the superficial fibromatoses, have a higher recurrence rate and mostly involve deep portions of the trunk and extremities. The descriptive term desmoid tumor is still used just like the less common synonym non metastasizing fibrosarcoma. The microscopic appearence of extraabdominal desmoid is benign but they can attain a large size, easily recur, and infiltrate neighbouring tissues like a fibrosarcoma. The origin of extraabdominal desmoid is the connective tissue of the muscle, overlying fascia or aponeurosis. Clinical findings of extraabdominal fibromatosis: The lesion presents as a soft tissue mass. Patients complain of an insidious growing painless mass. At a later stage pain can occur related to motion of the involved muscle. The tumor may infiltrate or encase large nerves eventually leading to paralysis of the limb. It is most common in patients between puberty and the age of 40 years. Anatomical location: The most common sites of extraabdominal (desmoid) fibromatosis are the shoulder, chest wall and back, thigh, mesentery and the neck. In 28 % there is a history of trauma (surgery, accidental, or other physical factors) at the tumor site. Also genetic as well as endocrine factors are reported in the etiopathology of the disease. Multicentricity of desmoid has been described. In most of these the second growth develops proximally to the primary lesion in the same anatomical region.The average size of the tumor mass varies between 5 and 10 cm diameter, but larger sizes are not rare. The tumor is firm and appears like scar tissue. Differential diagnosis: Desmoids have to be differentiated from 1) fibrosarcoma 2) reactive fibrosis 3) scar and 4) nodular fasciitis. Recurrence: The recurrence rate averages 40 % and is most common in tumors located in the shoulder, pelvic girdle (gluteus muscle, muscles of the thigh, quadriceps muscle and muscles of the popliteal fossa) and neck. It appears in the first 2-3 years following resection. Treatment: The treatment is radical excision including a wide margin to prevent recurrence. Postoperative radiotherapy is indicated in incompletely excised tumors or positive margins. Follow-up and prompt treatment at recurrence is an alternative to immediate radiation therapy in case of positive surgical margins. Radiotherapy as a single therapy can be used in inoperable tumors or recurrent inoperable tumors. Adjuvant radiotherapy is useful to improve the local control for patients with high risk of recurrence. There is no difference in local control between patients treated for primary fibromatosis and after one or more recurrences using radiotherapy. Doses of at least 50-60 Gy must be used, 5-6 year local control is between 70-80 %. Hormonal status (oestrogens) may influence tumor growth. Tamoxifen therapy leads to a progressive decrease in size. Other alternative therapies are the use of Testolactone, NSAID (indomethacin, sulindac, or sulindac with warfarin and vitamin K1, indomethacin with ascorbate), low-dose chemotherapy using vinblastine and MTX or vinorelbine and MTX, and IFN-alpha +/- tretinoin.
Extraabdominal fibromatosis
Based on the provided MRI images (mainly T1-weighted sequences), a spindle- or dumbbell-shaped lesion can be seen in the soft tissue posterior to the right femur. Overall, the lesion shows relatively low signal intensity on T1-weighted images, but there is a localized nodular high-signal area on the proximal (cranial) side. The boundary between the lesion and the surrounding muscle layers is not well-demarcated, and it appears to infiltrate or envelop adjacent soft tissues in certain areas. The lesion is relatively large (exceeding 5 cm), suggesting a deep soft tissue mass. No evident bony destruction or abnormal marrow signal is observed; however, the lesion is closely related to the neighboring muscle tissue, with partially blurred margins.
Considering the patient’s age, tumor size, and growth pattern, deep fibromatosis (also known as “extra-abdominal desmoid” or “musculoaponeurotic fibromatosis”) should be given the highest priority.
Taking into account the patient’s age (40-year-old female), imaging characteristics of the lesion (dumbbell-shaped, predominantly low T1 signal with focal higher signal areas, located in deep tissue involving aponeuroses or muscular interspaces), and typical presentation described in clinical literature for deep fibromatosis, the most likely diagnosis is:
Deep Fibromatosis (Extra-abdominal Desmoid Tumor).
If uncertainty remains, a histological pathological examination (biopsy) is recommended for confirmation.
After surgery or radiotherapy, patients may experience local scar formation and functional limitations. The goals of rehabilitation include:
It is advised to use the FITT-VP principle to formulate a rehabilitation exercise program, progressing step by step:
During rehabilitation, if the patient has other comorbidities (e.g., osteoporosis, joint problems, or inadequate cardiopulmonary function), an individualized assessment is required, and careful supervision during training is necessary to avoid excessive loading or overexertion.
Disclaimer: This report is compiled based on the current available data and is for reference only. It cannot replace an in-person consultation or professional medical guidance. Specific diagnosis, treatment, and rehabilitation plans should be tailored to the patient’s actual condition and carried out under the supervision of a specialist or rehabilitation therapist.
Extraabdominal fibromatosis
