Bone tumors

00:00 / 00:00



Bone tumors

Musculoskeletal system


Bone tumors


0 / 62 complete

USMLE® Step 1 questions

0 / 9 complete

High Yield Notes

9 pages


Bone tumors

of complete


USMLE® Step 1 style questions USMLE

of complete

A 67-year-old man comes to the clinic due to progressive fatigue and back pain over the past few months. Initially, the patient attributed the pain to strenuous work in the garden but decided to seek care when he noticed no improvement. The patient also noted a 10 lb (4.5 kg) weight loss without changes in his diet. Medical history is significant for smoking 1 pack of cigarettes per day for 35 years and diabetes mellitus type 2. Laboratory values are obtained and shown below:  
 Laboratory value  Result 
 Hemoglobin  11.2 g/dL 
 Mean corpuscular hemoglobin   90 fl 
 Creatinine   2.3 mg/dL 
 Total protein  9.5 
 Albumin  3.2 g/dL 
 Sodium   132 mEq/L 
 Potassium   4.2 mEq/L 
 Chloride   95 mEq/L 
 Calcium  12 mg/dl  

Radiograph of the spine reveals multiple areas of hyperlucency at the lumbar and thoracic regions. Which of the following is the most likely underlying cause? 

External References

First Aid








Bone cancer p. 473

primary bone tumors p. 474

Bone tumors p. 474-475

“Brown” bone tumor p. 722


Bone tumors form when a bone cell divides uncontrollably and forms a mass or tumor.

If the tumor remains confined and doesn’t spread into surrounding tissues, then it’s considered benign.

But if the tumor invades into surrounding tissues and metastasizes or spreads through blood or lymph, then it’s considered malignant.

Malignant tumors can either be primary which is when they arise from the bone cells, or secondary, which is when a tumor developed somewhere else in the body, metastasized, and spread to the bones.

The most common sources of tumor cells that affect the bones but start somewhere else in the body, are the breast, prostate, the lungs, the thyroid, and the kidneys.

Now, even though the bones vary in size and shape, they are all made of the same types of cells, and chief among them are osteoblasts which build up new bone, and osteoclasts which help with bone breakdown or resorption.

Now in addition to these, there are some more primitive cells in the bone marrow called human mesenchymal stem cells and neuroectodermal cells, which have the ability to differentiate into many cell types including nerve, fat, bone, and cartilage cells.

Now, in terms of anatomy, looking at a long- bone like the femur - it has two epiphyses, which are the ends that contribute to joints with other bones.

Between the two epiphyses, is the diaphysis, also called the bone shaft.

In children and adolescents, there is an additional narrow portion between the epiphysis and the diaphysis called the metaphysis.

The metaphysis contains the growth plate, the part of the bone that grows during childhood.

In adults the growth plate has ossified and fused with the diaphysis and the epiphysis.

Now, there are genes that promote normal cell growth called proto-oncogenes.


  1. "Robbins Basic Pathology" Elsevier (2017)
  2. "Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2)" McGraw-Hill Education / Medical (2018)
  3. "Pathophysiology of Disease: An Introduction to Clinical Medicine 8E" McGraw-Hill Education / Medical (2018)
  4. "CURRENT Medical Diagnosis and Treatment 2020" McGraw-Hill Education / Medical (2019)
  5. "Normal Bone Anatomy and Physiology" Clinical Journal of the American Society of Nephrology (2008)
  6. "Osteoid osteoma: diagnosis and treatment" Radiologia Brasileira (2015)
  7. "Clinical and morphological characteristics of osteoid osteoma and osteoblastoma: a retrospective single-center analysis of 204 patients" Annals of Diagnostic Pathology (2014)
  8. "Diagnosis and treatment of Ewing sarcoma of the bone: a review article" Journal of Orthopaedic Science (2015)

Copyright © 2023 Elsevier, its licensors, and contributors. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Cookies are used by this site.

USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). COMLEX-USA® is a registered trademark of The National Board of Osteopathic Medical Examiners, Inc. NCLEX-RN® is a registered trademark of the National Council of State Boards of Nursing, Inc. Test names and other trademarks are the property of the respective trademark holders. None of the trademark holders are endorsed by nor affiliated with Osmosis or this website.