Curriculum

17 Sections
1548 Lessons
100 Days

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U01.01 Biochemistry
This biochemistry review for USMLE Step 1 covers essential topics including metabolism, enzymology, and molecular biology.
126
U01.02 Immunology
Prepare for USMLE Step 1 Immunology with a comprehensive review covering foundational concepts, immune system mechanisms, and key disorders to solidify your understanding and boost exam readiness.
42
U01.03 Microbiology
Review essential microbiology topics for the USMLE Step 1, covering key pathogens, mechanisms of disease, and antimicrobial principles critical for mastering infectious disease concepts.
172
U01.04 General Pathology
Explore key concepts in general pathology essential for the USMLE Step 1. This review covers fundamental principles, disease mechanisms, and clinical correlations to help you excel in your medical exam.
35
U01.05 Pharmacology
Master key pharmacology concepts for the USMLE Step 1 with a focus on drug mechanisms, therapeutic uses, adverse effects, and interactions essential for high-yield exam performance.
43
U01.06 Public Health Sciences
Review essential Public Health Sciences topics for the USMLE Step 1, covering epidemiology, biostatistics, health policy, and ethics to strengthen your understanding of foundational public health principles.
53
U01.07 Cardiovascular system
Comprehensive review of essential cardiovascular system topics to help you excel in the USMLE Step 1 exam, covering key concepts from anatomy to pathology.
73
U01.08 Endocrine system
Master essential concepts of the endocrine system for USMLE Step 1, covering hormone regulation, feedback mechanisms, and key disorders to boost your exam readiness.
51
U01.09 Gastrointestinal system
Review key topics in the gastrointestinal system for the USMLE Step 1, covering essential concepts in anatomy, physiology, pathology, and pharmacology to reinforce your understanding and test readiness.
131
U01.10 Hematology and Oncology
This review covers essential Hematology and Oncology topics for the USMLE Step 1, including hematopoiesis, coagulation, anemias, leukemias, lymphomas, and neoplastic syndromes.
148
U01.11 Musculoskeletal, Skin, and Connective Tissue
Review essential topics for the USMLE Step 1 Musculoskeletal, Skin, and Connective Tissue systems, covering anatomy, physiology, pathology, and pharmacology fundamentals critical for exam success.
178
U01.12 Neurology and Special Senses
Master the foundational concepts of Neurology and Special Senses with our USMLE Step 1 review, covering essential topics like neuroanatomy, neurophysiology, and sensory pathways.
143
U01.13 Psychiatry
Psychiatry for the USMLE Step 1 focuses on understanding the pathophysiology, diagnosis, and treatment of psychiatric disorders, with an emphasis on key concepts like neurotransmitter imbalances, mental health disorders, and pharmacology.
83
U01.14 Renal System
The Renal System review for USMLE Step 1 covers key concepts including renal physiology, nephron function, acid-base balance, electrolyte regulation, and renal pathology, crucial for understanding both normal and abnormal kidney functions.
81
U01.15 Reproductive System
The USMLE Step 1 Reproductive System review covers key concepts in human reproduction, including anatomy, physiology, endocrinology, and common pathologies affecting both male and female reproductive health.
124
U01.16 Respiratory System
The Respiratory System review for the USMLE Step 1 covers key concepts in anatomy, physiology, pathophysiology, and pharmacology essential for understanding respiratory diseases and treatments.
61
U01.17 Rapid Review
he USMLE Step 1 Rapid Review covers essential topics across multiple disciplines, providing a concise, high-yield overview to reinforce key concepts and optimize your exam preparation.
5

Adult primary brain tumors

Adult primary brain tumors are classified based on their origin, histology, and clinical behavior. The following is a breakdown of common primary brain tumors in adults, including descriptions, histological features, and clinical characteristics.

Glioblastoma Multiforme

Description:

Grade IV Astrocytoma: Common, highly malignant primary brain tumor.
Median Survival: Approximately 1 year.
Location: Predominantly in the cerebral hemispheres, can cross the corpus callosum (known as the “butterfly glioma”).

Histology:

Origin: Astrocyte.
Markers: GFAP positive (Glial Fibrillary Acidic Protein).
Histological Features:
- “Pseudopalisading” tumor cells surround central areas of necrosis, hemorrhage, and microvascular proliferation.

Oligodendroglioma

Description:

Frequency: Relatively rare, slow-growing.
Location: Most often in the frontal lobes.
Characteristic: Often calcified.

Histology:

Origin: Oligodendrocyte.
Histological Features:
- “Fried Egg” Cells: Round nuclei with clear cytoplasm.
- “Chicken-Wire” capillary pattern.

Meningioma

Description:

Frequency: Common, typically benign.
Gender Distribution: More common in females.
Location: Occurs near brain surfaces, particularly in the parasagittal region.
Clinical Presentation: Often asymptomatic but may present with seizures or focal neurologic signs. Resectable or treatable with radiosurgery.

Histology:

Origin: Arachnoid cells.
Histological Features:
- Spindle Cells: Arranged concentrically in a whorled pattern.
- Psammoma Bodies: Laminated calcifications.

Hemangioblastoma

Description:

Location: Most often in the cerebellum.
Association: Strong link to von Hippel-Lindau syndrome, especially when associated with retinal angiomas.
Clinical Feature: Can produce erythropoietin, leading to secondary polycythemia.

Histology:

Origin: Blood vessels.
Histological Features:
- Thin-walled capillaries: Closely arranged with minimal intervening parenchyma.

Pituitary Adenoma

Description:

Types: Nonfunctioning (silent) or hyperfunctioning (hormone-producing).
Nonfunctional: Presents with mass effects, such as bitemporal hemianopia (due to pressure on the optic chiasm).
Prolactinoma: Commonly presents as galactorrhea, amenorrhea, and decreased bone density in women. In men, it presents with reduced libido and infertility.
Treatment: Dopamine agonists (e.g., bromocriptine, cabergoline) or transsphenoidal resection.

Histology:

Origin: Hyperplasia of endocrine cells in the pituitary.
Histological Features:
- Most Common: Lactotrophs (producing prolactin).
- Other Types: Somatotrophs (GH), corticotrophs (ACTH), less commonly thyrotrophs (TSH), gonadotrophs (FSH, LH).

Schwannoma

Description:

Location: Typically at the cerebellopontine angle, involving cranial nerves V, VII, and VIII. Commonly localized to CN VIII in the internal acoustic meatus, resulting in vestibular schwannoma, which can present with hearing loss and tinnitus.
Association: Bilateral vestibular schwannomas are characteristic of Neurofibromatosis Type 2 (NF-2).
Treatment: Surgical resection or stereotactic radiosurgery.

Histology:

Origin: Schwann cells.
Histological Features:
- S-100 Positive.
- Biphasic Pattern: Dense, hypercellular areas alternating with hypocellular, myxoid regions.

Points to Remember

Glioblastoma Multiforme: Highly malignant, with a poor prognosis (median survival ~1 year).
Oligodendroglioma: Slow-growing, commonly found in frontal lobes, and often calcified.
Meningioma: Benign, typically asymptomatic but can present with seizures.
Hemangioblastoma: Associated with von Hippel-Lindau syndrome, often cerebellar.
Pituitary Adenoma: Can be functional or nonfunctional, with prolactinomas being common.
Schwannoma: Involves cranial nerves, particularly CN VIII, with characteristic histological patterns.

Tables

Tumor Type	Origin	Location	Clinical Features	Histological Features
Glioblastoma	Astrocyte	Cerebral hemispheres	Poor prognosis, median survival ~1 year	GFAP+, pseudopalisading cells, necrosis, hemorrhage
Oligodendroglioma	Oligodendrocyte	Frontal lobes	Slow-growing, often calcified	Fried egg cells, chicken-wire capillary pattern
Meningioma	Arachnoid cells	Near brain surfaces, parasagittal region	Seizures, focal neurologic signs	Whorled pattern, psammoma bodies
Hemangioblastoma	Blood vessels	Cerebellum	Secondary polycythemia, associated with von Hippel-Lindau syndrome	Thin-walled capillaries, minimal intervening parenchyma
Pituitary Adenoma	Endocrine cells	Pituitary gland	Visual disturbances (bitemporal hemianopia), prolactinoma symptoms	Hyperplasia of pituitary cells, prolactin, GH, ACTH
Schwannoma	Schwann cells	Cerebellopontine angle, CN VIII	Hearing loss, tinnitus, NF-2 association	Biphasic pattern, S-100+

Adult primary brain tumors

USMLE Step 1 Review Series

Curriculum

Adult primary brain tumors

Glioblastoma Multiforme

Description:

Histology:

Oligodendroglioma

Description:

Histology:

Meningioma

Description:

Histology:

Hemangioblastoma

Description:

Histology:

Pituitary Adenoma

Description:

Histology:

Schwannoma

Description:

Histology:

Points to Remember

Tables

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