Page Contents
OVERVIEW
This page is dedicated to organizing various examples of standardized exam questions whose answer is neurofibromatosis Type 1. While this may seem a odd practice, it is useful to see multiple examples of how neurofibromatosis Type 1 will be characterized on standardized exams (namely the boards and the shelf exams). This page is not meant to be used as a tradition question bank (as all of the answers will be the same), however seeing the classic “test” characterization for a disease is quite valuable.
KEY CHARACTERISTICS OF THIS CONDITION (ON EXAMS)
When it comes to standardized exams, each condition has its own “code” marked by key buzzwords, lab findings, clues, etc. If you are well versed in this code you will be able to more quickly identify the condition that is being discussed, and get the right answer on the exam you are taking. Below is the “code” for neurofibromatosis Type 1.
- Cafe au lait macules: hyperpigmented lesions with either smooth or irregular borders.
- Neurofibromas: short, sessile, or pedunculated lesions throughout the body. Usually are present in multiples.
- Lisch nodules: pigmented hamartomas in the iris.
QUESTION EXAMPLES
Question # 1
A 13 year old boy is brought to the clinic because of a history of a learning disability and hyperactivity. His teacher explains that she feels he has a short attention span. His father explain that the child can not concnetratre on his homework. The patient has had a generalized tonic-clonic seizure about 8 years ago. An exam shows 10 lesions with a coffee-stain appearance on the chest and abdomen. There are small areas of increased pigmentation on the axial and there are also many small skin tags seen on the back, chest, and the abdomen. What is the most likely diagnosis in this patient?
Explanation: Cafe au lait macules = neurofibromatosis Type 1
Question # 2
A 3 year old girl is brought to the clinic because her father has noticed that she has developed several brown colored spots over her back since brith. The patient’s mother also has similar spots as well as several 1 cm lumps under the skin, and scoliosis as well. A dermatological exam reveals that the patient has four 1.5 cm brown macules over her back. What is the likely diagnosis?
Explanation: Cafe au lait macules = neurofibromatosis Type 1
TESTABLE FACTS ABOUT THIS CONDITION (BEYOND ITS IDENTIFICATION)
Many questions on standardized exams go beyond simply recognizing the underlying condition. Often there are specific testable facts regarding some aspect of the disease’s pathophysiology/management/clinical implications that are commonly asked. Some of these are listed below:
- What causes it: singe gene mutation in the NF1 gene (chromosome 17).
- Inheritance pattern: autosomal dominant.
- Associated conditions:
- Eye: optic nerve glioma, Lisch nodules
- Bony abnormalities: sphenoid dysphasia, congenital psuedoarthrosis, scoliosis
- Other associated tumors: meningioma, astrocytoma, glioma, pheochromocytoma.
Page Updated: 11.08.2016