10. Pathology and Oncology MCQs

A 22-year-old male complains of chronic, mild left knee pain. Imaging reveals an eccentric, well-defined, lytic lesion in the proximal tibial metaphysis with a scalloped, sclerotic margin. Histological examination of curettage material displays a lobular architecture featuring a hypocellular myxochondroid center containing stellate cells and a hypercellular periphery containing spindle cells and occasional multinucleated giant cells.

What is the most appropriate initial treatment for this lesion?

A 7-year-old boy presents with a painful lytic lesion in the skull and a separate localized lytic lesion in the clavicle. A biopsy of the clavicular lesion reveals sheets of mononuclear cells with characteristic grooved "coffee bean" nuclei intermingled with numerous eosinophils. Immunohistochemistry shows the cells are positive for CD1a and Langerin (CD207).

Which of the following specific genetic mutations is most frequently identified in the pathogenesis of this disease?

A 38-year-old female presents with recurrent, massive knee swelling, stiffness, and pain. MRI demonstrates a large joint effusion and extensive nodular synovial proliferation that shows distinctly low signal intensity on both T1- and T2-weighted images due to hemosiderin deposition.

Recent advances in systemic targeted therapy for advanced, unresectable forms of this specific disease are designed to inhibit which of the following pathways?

A 35-year-old male presents with chronic, dull pain in his left hip. Radiographs demonstrate a radiolucent lesion located within the proximal femoral epiphysis. A biopsy is performed, and histologic examination reveals lobules of cells with distinct cell membranes and abundant clear cytoplasm, interspersed with woven bone and areas of chondroid matrix. What is the most likely diagnosis?

A 14-year-old girl presents with progressive pain and swelling over her proximal fibula. Radiographs demonstrate an expansile, multiloculated lytic lesion as seen in the representative radiograph.

A core needle biopsy confirms a primary aneurysmal bone cyst (ABC). Which of the following genetic alterations is most characteristic of primary aneurysmal bone cysts?

A 28-year-old female presents with a painless, slow-growing mass on the posterior aspect of her distal thigh. Radiographs reveal a densely mineralized, lobulated mass attached to the posterior cortex of the distal femur via a broad base. Biopsy reveals a low-grade spindle cell proliferation with well-formed woven bone trabeculae. Which of the following molecular alterations is most commonly associated with this tumor?

A 30-year-old male presents with anterior tibial bowing and a persistent dull ache in his leg. Radiographs display a multilocular, 'soap-bubble' appearing lytic lesion in the anterior diaphysis of the tibia. Biopsy demonstrates nests of uniform epithelial cells surrounded by a spindle cell fibrous stroma. Immunohistochemistry shows strong positivity for cytokeratin. What is the most likely diagnosis?

A 60-year-old male presents with insidious onset of bowel and bladder dysfunction, accompanied by localized sacral pain. Imaging shows a large, destructive midline sacral mass.

Histologic examination demonstrates cords of large cells with abundant vacuolated cytoplasm within a myxoid stroma. Which of the following immunohistochemical markers is highly sensitive and specific for the diagnosis of this neoplasm?

A 25-year-old male undergoes routine pelvic radiographs after a minor trauma. The films fortuitously reveal numerous 2 to 10 mm distinct sclerotic foci clustered near the joint spaces of the pelvis and proximal femurs. He is otherwise completely asymptomatic but mentions a history of connective tissue nevi (dermatofibrosis lenticularis disseminata). What gene mutation is established as the cause of this skeletal condition?

A 45-year-old male presents with a deep, painless intramuscular mass in the anterior thigh. Biopsy reveals a proliferation of small, uniform round-to-oval cells, a prominent plexiform capillary network resembling 'chicken-wire', and small mucin-filled lipoblasts in a myxoid background. Which chromosomal translocation is characteristic of this tumor?

A 32-year-old female presents with a slow-growing, painful mass near her knee joint. MRI reveals a deep, well-circumscribed soft tissue mass adjacent to the joint capsule.

Histopathology shows a biphasic tumor comprised of both spindle cells and epithelial-like glandular structures. Which of the following is true regarding this tumor?

A 7-year-old boy presents with severe back pain. Radiographs reveal vertebra plana (flattening) of the T8 vertebral body. A CT-guided needle biopsy demonstrates a dense infiltrate of cells with folded, grooved nuclei intermixed with numerous eosinophils. If electron microscopy were performed on this biopsy specimen, it would most likely reveal which of the following pathognomonic structures?

A 65-year-old male presents with a large, destructive, expansile lytic lesion of the proximal humerus with an impending fracture. A needle biopsy confirms metastatic clear cell carcinoma consistent with a renal primary. He is scheduled for a wide excision and endoprosthetic reconstruction. To minimize intraoperative complications, what is the most appropriate next step in management prior to surgery?

A 15-year-old male presents with multiple asymmetric hard nodules on his hands and fingers, causing deformity. He also has several bluish, compressible soft tissue masses on his forearms. He has a known history of multiple enchondromas. Which of the following is the most accurate statement regarding his condition?

A 45-year-old asymptomatic female undergoes a lumbar spine MRI for mild mechanical back pain. An incidental finding at the L3 vertebral body is noted.

The discrete lesion is hyperintense on both T1- and T2-weighted MRI sequences. A subsequent CT scan reveals a 'polka-dot' appearance in the axial plane and coarse vertical trabeculations in the sagittal plane. What is the most likely diagnosis?

A 22-year-old male presents with chronic mid-back pain. He describes the pain as a dull, constant ache that is not reliably relieved by NSAIDs. A CT scan of the thoracic spine shows a 3.5 cm expansile, radiolucent lesion with scattered matrix calcifications originating in the posterior elements of T10. Histology demonstrates interconnected trabeculae of woven bone lined by prominent, plump osteoblasts within a highly vascularized connective tissue stroma. What is the most likely diagnosis?

A 35-year-old male presents with recurrent, spontaneous hemarthrosis and a boggy, painless swelling of the right knee. MRI demonstrates a villous, nodular intra-articular synovial mass.

The mass exhibits a profound 'blooming artifact' on gradient-echo sequences. Which molecular alteration is the primary driver of this disease process?

A 5-year-old boy presents with progressive anterior bowing of the left tibia. Radiographs reveal a sharply marginated, radiolucent, intracortical lesion in the anterior diaphyseal cortex of the tibia with a sclerotic margin. Biopsy confirms woven bone trabeculae rimmed by prominent osteoblasts within a bland fibrous stroma. No epithelial nests are seen. What is the recommended initial management for this lesion, assuming no impending fracture?

A 19-year-old male presents with persistent right pelvic pain. Radiographs show a large, aggressive-appearing lytic lesion in the right ilium with cortical breakthrough. Biopsy demonstrates a hypocellular proliferation of bland, benign-appearing spindle cells (fibroblasts) separated by abundant dense collagen bundles. No cytologic atypia, pleomorphism, or mitotic figures are observed. This rare primary bone tumor is considered the osseous counterpart of which of the following soft tissue lesions?

A 65-year-old male presents with severe back pain and generalized fatigue. Radiographs demonstrate multiple 'punched-out' lytic lesions in the skull and pelvis.

A bone marrow biopsy confirms 20% clonal plasma cells. According to the classic 'CRAB' criteria, which of the following findings is NOT an accepted criterion defining end-organ damage in symptomatic multiple myeloma?