PA34.1-3,PA35.1 | Nervous System & Eye — Practice Quiz

A 6-year-old child presents with fever, neck stiffness, and petechial rash for 18 hours. Lumbar puncture is performed. Which CSF profile is MOST consistent with bacterial meningitis?

A 28-year-old immunocompetent medical student develops headache and low-grade fever over 3 days. CSF analysis: opening pressure 160 mmH₂O, appearance clear, cells 110/mm³ (92% lymphocytes), protein 55 mg/dL, glucose 58 mg/dL (simultaneous serum glucose 95 mg/dL). Gram stain and culture are negative. Which diagnosis fits BEST?

A 45-year-old HIV-negative patient with prolonged fever, night sweats, and weight loss presents with meningism. CSF: cells 180/mm³ (85% lymphocytes), protein 320 mg/dL, glucose 28 mg/dL (serum 88 mg/dL). After standing overnight the tube shows a fine 'cobweb' clot. AFB smear is pending. Which meningitis type does this profile MOST likely represent?

On histology of a brain tumour biopsy, you observe areas of necrosis with a rim of densely packed, hyperchromatic tumour cells arranged in a radial pattern around the necrotic core. Microvascular proliferation with glomeruloid tufts is also present. Which tumour and molecular marker best characterises this finding?

A 55-year-old woman undergoes craniotomy for a parasagittal mass compressing the brain from outside. Histology shows meningothelial cells arranged in concentric whorls with laminated, concentrically calcified spherical structures. The tumour is well-delineated and does not infiltrate brain parenchyma. What is the diagnosis?

Brain biopsy of a frontal lobe tumour in a 35-year-old man shows uniform round nuclei surrounded by clear cytoplasmic halos ('fried-egg' artefact) and a delicate branching vasculature resembling 'chicken wire'. Molecular analysis reveals co-deletion of chromosomes 1p and 19q. What is the diagnosis?

A 7-year-old boy presents with morning headache, vomiting, and ataxia. MRI shows a midline posterior fossa mass filling the 4th ventricle. Histology reveals densely packed small blue cells with hyperchromatic nuclei and scant cytoplasm forming circular arrangements around a central fibrillary core. Which feature and tumour does this BEST describe?

A 30-year-old woman with neurofibromatosis type 2 (NF2) develops hearing loss and tinnitus. MRI reveals a well-circumscribed, enhancing mass at the cerebellopontine angle attached to the vestibulocochlear nerve (CN VIII). Histology shows two alternating patterns: cellular areas with nuclear palisading ('Verocay bodies') and loose myxoid areas. Which tumour is this?

A 60-year-old woman with known breast carcinoma develops multiple ring-enhancing lesions at the grey-white junction of both cerebral hemispheres. Biopsy of one lesion shows nests of epithelial cells with ductal features surrounded by reactive gliosis. What is the MOST likely diagnosis and key pathological clue?

A 2-year-old girl is brought to the ophthalmologist because her mother noticed a white reflex from the right eye in photographs (leukocoria). Examination under anaesthesia shows a white intraocular mass. Enucleation is performed. Histology reveals small blue cells forming rosettes with a central lumen lined by columnar cells resembling primitive photoreceptors. Which genetic mechanism BEST explains the hereditary form of this tumour?

A retinoblastoma patient successfully treated in childhood later develops a painful swelling of the distal femur at age 18. Biopsy of the femoral lesion shows malignant spindle and osteoid-producing cells. Which statement BEST explains this second malignancy?

On histology of an enucleated eye from a 3-year-old, you identify two types of rosettes. Type 1 shows tumour cells arranged around a central LUMEN with no cytoplasmic processes filling it; Type 2 shows cells around a central mass of FIBRILLAR cytoplasmic processes with NO lumen. Which pairing correctly identifies both rosette types and their associated tumours?