Female, 78 years old. Reason: please define margins of right buttock neurofibroma History: painful right buttock lesion in woman with NF1 and history of a malignant peripheral nerve sheath tumor There is a well-defined mass within the subcutaneous fat of the right buttock that measures approximately 6 x 4 cm in transverse dimension and 4.5 cm in craniocaudal dimension. Its signal intensity is similar to that of skeletal muscle on T1-weighted images. It is heterogeneous on fat-suppressed T2-weighted images containing foci that are isointense to hyperintense to skeletal muscle. On a CT scan from 12/04/2014, this mass was approximately 5.1 x 3.8 cm in transverse dimension and 3.4 cm in craniocaudal dimension. The overlying skin appears thickened. Currently the mass does not appear to abut the underlying gluteal musculature. There is a small plaque-like lesion lateral to the mass which is presumed to represent a cutaneous neurofibroma. Multiple additional cutaneous neurofibromas are noted bilaterally. A mass within the subcutaneous fat of the posterior left buttock measures approximately 3 cm in greatest dimension, representing an additional neurofibroma, similar size to that seen on the prior CT scan. An amorphous mass within the musculature anterior to the proximal left femur and probably involving the inferior aspect of the left hip joint is associated with chronic erosion of the anterior aspect of the proximal femoral. It measures approximately 5 x 6 cm in transverse dimension and 15 cm in craniocaudal dimension. This mass was present on the prior CT study from 12/2014, but it is difficult to evaluate for changes in size between the two studies. This mass is predominantly isointense to skeletal muscle on T1-weighted images and heterogeneously hyperintense to skeletal muscle on T2-weighted images. A smaller neurofibroma is seen anterior to this mass within the rectus femoris muscle. A couple of additional intramuscular neurofibromas are noted. A structure of intermediate to high signal within the left adnexal region probably represents an intrapelvic neurofibroma. A mass of low signal intensity within the uterus likely represents a fibroid.Heterogeneous appearance of medullary bone likely reflects residual or reconverted red marrow. Mild osteoarthritis affects the hips and sacroiliac joints. Severe degenerative disc disease affects L5-S1.
Findings compatible with neurofibromatosis with neurofibromas as described above. The right buttock neurofibroma appears to have increased in size slightly from the CT study dated 12/2014. Please note that we cannot determine on the basis of imaging if this mass is benign or malignant.