Practice Set 3 of 6
This practice set contains high-yield board review questions covering key concepts in Soft Tissue Tumors & Metastasis. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.
Which anatomic location is most commonly affected by Lipoma Arborescens?
. Suprapatellar pouch of the knee
Histologic examination of a specimen retrieved from a patient with lipoma arborescens will classically demonstrate which of the following?
. Replacement of subsynovial tissue by mature adipocytes
In which anatomic location is lipoma arborescens most frequently identified?
. Suprapatellar pouch of the knee
A 45-year-old woman presents with recurrent knee effusions. MRI reveals a villous, lipomatous synovial proliferation.
Which MRI sequence change will confirm the diagnosis of lipoma arborescens by extinguishing the high signal of the lesion?
. Fat-suppressed sequence (e.g., STIR)
Histological examination of a specimen retrieved from a knee synovectomy in a patient with suspected lipoma arborescens will most likely demonstrate which of the following?
. Replacement of sub-synovial tissue by mature adipocytes
What is the most common anatomical location for the development of lipoma arborescens?
. Suprapatellar pouch of the knee
Lipoma arborescens is most frequently observed in which of the following anatomic locations?
. Suprapatellar pouch of the knee
A 38-year-old female presents with a slowly enlarging, boggy right knee effusion. MRI reveals a large, villous synovial mass in the suprapatellar pouch.
To reliably differentiate lipoma arborescens from Pigmented Villonodular Synovitis (PVNS) on MRI, which of the following imaging characteristics is most uniquely diagnostic of lipoma arborescens?
. Complete suppression of the synovial mass signal on fat-saturated T1-weighted sequences
A 45-year-old male undergoes excision of a deep thigh mass. Pathology demonstrates a myxoid stroma, a prominent plexiform ("chicken-wire") capillary network, and scattered lipoblasts. Which genetic alteration is most likely present?
. t(12;16)
A 45-year-old female presents with a painless 10 cm soft tissue mass in her retroperitoneum, discovered incidentally. Biopsy reveals atypical lipoblasts with an amplified MDM2 gene. What is the most likely diagnosis?
. Well-differentiated liposarcoma
. Connective tissue nevi (Buschke-Ollendorff syndrome)
Which subtype of liposarcoma is unique in its tendency to spread to extrapulmonary sites, specifically necessitating a whole-spine MRI during initial staging to rule out bone metastases?
. Myxoid liposarcoma
Which of the following chromosomal translocations is highly characteristic of myxoid liposarcoma?
. t(12;16) FUS-DDIT3
A 55-year-old presents with a painless, enlarging thigh mass. Histology demonstrates mature adipocytes with variation in cell size, scattered hyperchromatic stromal cells, and lipoblasts. Molecular testing is positive for CDK4 amplification. What is the most likely diagnosis?
. Well-differentiated liposarcoma
Pleomorphic liposarcoma is the rarest and most aggressive subtype of liposarcoma. Unlike well-differentiated and myxoid liposarcomas, molecular analysis of a pleomorphic liposarcoma typically exhibits:
. Complex and unbalanced karyotypes without a specific signature translocation
Which subtype of liposarcoma is characterized histologically by a prominent branching capillary network resembling a "chicken-wire" vascular pattern, abundant mucinous stroma, and small lipoblasts?
. Myxoid liposarcoma
Among the main histological subtypes of liposarcoma, which carries the worst overall prognosis, highest rate of metastasis, and is characterized by a complex karyotype lacking a specific, defining chromosomal translocation?
. Pleomorphic liposarcoma
Which of the following macroscopic and microscopic growth patterns best differentiates a solitary neurofibroma from a schwannoma?
. Central growth with intimate incorporation of nerve fascicles
A 30-year-old male is diagnosed with Neurofibromatosis type 2 (NF2). He is at highest risk for developing which of the following pathognomonic lesions?
. Bilateral vestibular schwannomas
Which of the following microscopic features is a classic hallmark of a neurofibroma?
. Wavy spindle cells with interspersed mast cells and collagen bundles