1. General Principles & Basic Science MCQs

A 22-year-old female presents with a destructive, eccentric, lytic lesion in the distal radius subchondral bone. Histology shows sheets of mononuclear cells with numerous multinucleated giant cells. Which targeted pharmacological therapy is indicated if the tumor is deemed unresectable or for massive recurrence?

In a patient with known syringomyelia who presents with rapidly progressive neuropathic arthropathy (Charcot joint) of the elbow, what is the primary pathophysiological mechanism leading to joint destruction?

A 45-year-old male presents with massive, painless swelling of his right shoulder and noticeable crepitus on range of motion. Neurological examination reveals a loss of pain and temperature sensation in a 'cape-like' distribution over his shoulders and back, but intact light touch and proprioception.

Based on the clinical presentation, what is the most likely diagnosis of the shoulder pathology?

A 4-year-old girl is diagnosed with pauciarticular juvenile idiopathic arthritis (JIA). Her laboratory tests reveal she is ANA positive and Rheumatoid Factor (RF) negative. According to current guidelines, what is the most appropriate screening protocol for extra-articular manifestations in this patient?

A 32-year-old female presents with a purely lytic, eccentric lesion in the epiphysis extending into the metaphysis of the distal femur. A biopsy reveals numerous multinucleated giant cells in a stroma of mononuclear cells. If medical therapy is considered, which drug specifically targets the primary molecular pathway driving this tumor?

A 7-year-old girl is admitted with daily spiking fevers up to 39.5°C, a salmon-pink macular rash on her trunk, polyarthritis, and hepatosplenomegaly. Which of the following laboratory markers is most characteristically elevated out of proportion to other inflammatory markers in this specific condition?

A 65-year-old male presents with widespread lytic bone lesions, renal insufficiency, and hypercalcemia. A diagnosis of Multiple Myeloma is established. Which of the following best describes the molecular mechanism responsible for the osteolytic bone lesions in this disease?

A 10-year-old girl with polyarticular juvenile idiopathic arthritis develops severe involvement of her temporomandibular joints (TMJs). Which of the following facial abnormalities is the expected consequence of chronic TMJ destruction during her growth phase?

A 4-year-old girl is diagnosed with oligoarticular Juvenile Idiopathic Arthritis (JIA) after presenting with a swollen, painless right knee. Laboratory testing reveals a positive antinuclear antibody (ANA). Which of the following is the most critical routine screening study required for this patient?

A 6-year-old boy presents with daily high spiking fevers, an evanescent salmon-pink macular rash on his trunk, generalized lymphadenopathy, and symmetric polyarthritis. Laboratory tests show elevated ferritin, CRP, and leukocytosis. What is the most likely diagnosis?

In a patient developing syringomyelia, the expanding syrinx initially causes bilateral loss of pain and temperature sensation while preserving touch and proprioception. Which specific spinal cord structure is compressed first to cause this presentation?

As a cervical syrinx progressively enlarges ventrally, it begins to compress and destroy adjacent structures beyond the central commissure. Which of the following neurological findings in the upper extremities is a classic consequence of this ventral extension?

A 5-year-old boy with systemic Juvenile Idiopathic Arthritis (sJIA) suddenly develops unremitting fever, hepatosplenomegaly, purpura, and profound lethargy. Laboratory tests show marked hyperferritinemia, hypofibrinogenemia, and pancytopenia. What is the most critical immediate complication?

Which of the following subsets of Juvenile Idiopathic Arthritis (JIA) carries the highest risk for developing chronic, asymptomatic anterior uveitis?

A 6-year-old child with a known history of systemic-onset JIA (Still's disease) suddenly develops a high unremitting fever, hepatosplenomegaly, bleeding gums, and profound lethargy. Laboratory tests show a rapidly dropping platelet count and an exceptionally high serum ferritin level. What is the most likely diagnosis?

Giant Cell Tumor (GCT) of bone frequently causes significant local bone destruction. The osteolysis in GCT is driven by the interaction between RANKL and RANK. In this tumor, which cells express RANKL?

Which of the following demographic profiles is most characteristic for the onset of Dysplasia Epiphysealis Hemimelica (DEH)?

A 10-year-old male presents with limited knee flexion and a palpable mass in the popliteal fossa. Radiograph and MRI are shown below. The mass is seen protruding from the distal femoral epiphysis. What is the estimated incidence of this condition in the general population?

A 5-year-old boy is brought to the orthopedic clinic by his parents due to a noticeable deformity around his right knee. Which of the following symptom clusters is most characteristic of Dysplasia Epiphysealis Hemimelica (DEH) at presentation?

The term 'hemimelica' in Dysplasia Epiphysealis Hemimelica refers to a specific pattern of involvement. Which of the following best describes this characteristic pattern?