This category contains 30 posts

Sinonasal Osteosarcoma

History: 9 year old boy with nasal congestion and epistaxis (bloody nose) Osteosarcoma uncommonly arises in craniofacial bones, but when it does it occurs most often in bones of the jaw and has only very rarely been reported to arise in the nasal cavity or paranasal sinuses as a primary tumor. Most sinonasal osteosarcomas are high grade. … Continue reading

The Ventricular System of the Brain

The ventricular system is a set of four structures, the ventricles, containing cerebrospinal fluid (CSF) in the brain. It is continuous with the central canal of spinal cord. The ventricle lining consists of an epithelium-like membrane called ependyma. The ventricles are interconnected, allowing the flow of cerebrospinal fluid. CSF is produced by the ependymal cells … Continue reading

Suprasellar Mass – Rathke Cleft Cyst

History: 20 year old female with headache and blurry vision This is a case of a Rathke cleft cyst, which is a benign suprasellar mass. Rathke’s pouch is a depression in the roof of the developing mouth in front of the buccopharyngeal membrane. It gives rise to the anterior pituitary (adenohypophysis), a part of the endocrine system. Rathke’s pouch normally closes early … Continue reading

Message to Anti-vaxxers: Measles is More Than Just a Fever and a Rash

The vaccination debate is probably one of the hottest topics in medicine today. I’m not going to elaborate on the different issues at length, but two recent articles in lay media (USAToday and The New York Times) reminded me of a post I’ve always wanted to share. One of the most common arguments against vaccinations … Continue reading

Skull Metastases

History: Middle aged man with headache.  This is a case of lung cancer metastases to the skull. Lung cancer, like breast cancer, can produce both lytic and sclerotic bone metastases. Read about other cancers and the bone metastases they produce. Thank you to Dra. Pilar Rodríguez Pérez from Spain for submitting this case. See this patient’s … Continue reading

Diffuse Cerebral Edema

History: status post trauma with severe blood loss.  This is a case of diffuse cerebral edema secondary to exsanguination. The pathophysiology of diffuse cerebral edema in the case of exsanguination involves global brain ischemia secondary to hypoperfusion from hypovolemic shock. Brain ischemia leads to anaerobic metabolism that produces less adenosine triphosphate (ATP) and more lactate. … Continue reading


History: male with head trauma This is the best example of post-traumatic pneumocephalus I have seen personally outside of the literature. Pneumocephalus literally just means airhead, and is caused most often by trauma (in as many as 75% of cases). The second most common cause of pneumocephalus is iatrogenic from either ventricular shunt placement or … Continue reading

Ring Enhancing Intracranial Mass Mnemonic – MAGIC DR

This is a commonly used mnemonic to recall the differential diagnosis for ring enhancing intracranial masses: M – Metastases A – Abscess G – Glioblastoma Multiforme I – Infarct (subacute) C – Contusion D – Demyelinating disease (such as tumefactive multiple sclerosis) R – Radiation Necrosis and Resolving hematoma

Depressed Skull Fracture in an Infant – Non-accidental Trauma versus Accidental Trauma

History: Infant status post fall from 4 feet. This is the appearance of a depressed skull fracture in an infant. In the setting of skull fractures in an infant, one always has to rule out the presence of non-accidental trauma (NAT), which is medical-speak for child abuse. There are multiple characteristics of skull fractures which … Continue reading

Solution to Unknown Case # 13 – Fibrous Dsyplasia of the Skull Base

History: 10 year old girl with headaches and facial deformity. This is a case of fibrous dysplasia of the skull base. Fibrous dysplasia is a congenital bone disease resulting from abnormal osteoblast differentiation which results in the replacement of normal bone with a mixture of fibrous tissue and immature woven bone. It usually occurs in … Continue reading