What are the Common Benign Bone Tumors?

Patient Presentation
A 4-year-old female was sent to the emergency room of a regional children’s hospital for treatment of a right femur fracture.
The child had been playing outside with her older siblings and tripped over a sandbox while playing and hit her knee. She was able to get up and come into the house where she again fell in the doorway.
She refused to walk and was taken to a local emergency room. Radiographs were obtained and showed a non-displaced femur fracture located a bone lucency.
Because of the lucency she was sent to the children’s hospital for further evaluation and management.

The past medical history showed a healthy child with a normal diet. The family history showed heart disease and diabetes and no bone problems or cancer in the family. The review of systems was negative including weight loss, sweating, problems bruising or bleeding.

The pertinent physical exam showed a healthy 4 year old with normal growth.
Skin examination showed minor shin bruising. She had some mild redness over her right patella and complained of pain just above the knee with palpation and movement. Hip and ankle examination were normal as was the rest of her examination.

The radiologic evaluation showed an oblique non-displaced distal femur fracture through a radiolucent lesion with a well-defined border with no periosteal reaction. There was no soft tissue swelling. The diagnosis of non-ossifying fibroma with a pathological fracture of the femur was made.

The patient’s clinical course including consulting orthopaedics who placed her into a hip spica cast as a long leg cast would not be long enough to approximate and fix both fracture ends.
She was admitted to the hospital for cast placement and parental education about the cast. She was to followup in the orthopaedic clinic in 2 weeks.

Case Image

Figure 77 – AP and lateral radiographs of the right knee demonstrate an acute, non-displaced oblique pathologic fracture through the distal right femur that occurs in an underlying radiolucent lesion that is well marginated and most consistent in appearance with a non-ossifying fibroma.

Discussion
Fibrous cortical defect or non-ossifying fibroma (also called fibroxanthoma) is a common benign bony tumor. If < 4 cm and close to the cortex they are called fibrous cortical defects. If larger and if they enter into the intramedullary canal they are called non-ossifying fibromas. Up to 30% of children with open growth plates may have one.
Radiographs show ovoid, scalloped lucencies in the metaphyseal cortex of a long bone with a sharply marginated surrounding rim of reactive bone, with no associated soft tissue mass.
These tumors usually spontaneously resolve and usually no treatment for them is necessary.

Learning Point
Other Common benign bone tumors include:

  • Osteochondroma – Most common benign bone tumor in children. They are outgrowths of normal bone and cartilage that occur in abnormal locations usually in the metaphysis of long bones. Radiographs show normal tracecular bone and bone density with no reactive bony changes. Lesions can be pedunculated or sessile.
    Treatment is usually monitoring.

  • Bone cysts
    • Simple or unicameral – a cystic lesion located at the ends of long bones usually near the physis. Radiographically there is a lucency sometime with ridges of cortical bone. As they may have associated pathological fractures, treatment of the fracture is needed along with aspiration. Treatment with bone grafting also may be indicated.
    • Aneurysmal bone cysts – occur uncommonly in children usually in the long bones but also in the spine. They may occur in the metaphysis or diaphysis. Treatment is curretage and bone grafting.
  • Enchondroma – a cartilage tumor found in the hands and feet often in the diaphyseal or metaphyseal areas. They may be singular or multiple. Radiographs show a radiolucent lesion with thin cortex and little or no reactive bone. Sometimes there is speckled calcification within the lesion.
    Rarely has malignant transformation. Treatment is curretage and bone grafting.

  • Osteoid osteoma – painful lesions occurring often in the tibia and femur. Radiographs show a radiolucent nidus with surrounding dense reactive bone. Natural history is one of resolution but they are so painful that surgery may be necessary for relief.
  • Osteoblastoma – is similar to osteoid osteoma but occurs often in the spine, feet or ribs. These are also larger (> 1.3 cm in size). Some malignant variants have been reported.

Eosinophilic granulomas can be considered benign as they act benign but they are part of a system disease process that often needs treatment.
Chondroblastomas can also be considered benign but they often metastasize to other areas and it is not certain if they actually spontaneously resolve, therefore they are usually treated if found by resection, or other treatment.

Questions for Further Discussion
1. What are common malignant bone tumors and what is their radiographic appearance?
2. What are the indications for further radiological evaluation of a bone lesion?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for these topics: Benign Tumors and Bone Diseases.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

Jee H, Choe BY, Kang HS, et. al. Nonossifying fibroma: characteristics at MR imaging with pathologic correlation. Radiology, 1998;209:197-202.

Rudolph CD, et.al. Rudolph’s Pediatrics. 21st edit. McGraw-Hill, New York, NY. 2003:2451-2455.

Smith SE. Fibrous Cortical Defect and Nonossifying Fibroma. eMedicine. Available from the Internet at http://emedicine.medscape.com/article/389590-overview (rev. 11/27/2007, cited 4/27/2009).

ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients’ is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    4. Patient management plans are developed and carried out.
    5. Patients and their families are counseled and educated.
    7. All medical and invasive procedures considered essential for the area of practice are competently performed.
    8. Health care services aimed at preventing health problems or maintaining health are provided.
    9. Patient-focused care is provided by working with health care professionals, including those from other disciplines.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Practice Based Learning and Improvement
    13. Information about other populations of patients, especially the larger population from which this patient is drawn, is obtained and used.
    16. Learning of students and other health care professionals is facilitated.

  • Systems Based Practice
    23. Differing types of medical practice and delivery systems including methods of controlling health care costs and allocating resources are known.
    24. Cost-effective health care and resource allocation that does not compromise quality of care is practiced.
    25. Quality patient care and assisting patients in dealing with system complexities is advocated.

    Author
    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital

  • How Common Are Second Malignancies After a Primary Malignancy?

    Patient Presentation
    A 14-year-old female was referred from the emergency room with a one month history of constipation. She generally had regular soft stools but then began having bowel movements every 4+ days and later began having overflow encopresis. She said that she felt generally full in her abdomen and experienced pressure discomfort all the time but had no nausea or vomiting. She said that she had been eating less because she got full quickly. There was no blood or mucous in the stool.

    The past medical history was positive for being a 5-year survivor of a primary neuroectodermal tumor of the brain that was successfully treated with chemotherapy and radiotherapy. The family history was non-contributory. The review of systems was negative for any weight loss, sweating, difficulty walking or urinating or seizure activity.

    The pertinent physical exam showed a cooperative female in no distress with normal vital signs. She was at the 10% for height and 50% for weight. Her abdominal examination showed slight distention and was soft without hepatosplenomegaly. She had a mass in the left lower quadrant of the abdomen which was approximately 8 x 4 centimeters in size that was mobile. The rest of her examination was normal. The mass remained palpable after an enema produced a moderate amount of stool.

    The radiologic evaluation of a computed tompgraphy showed a soft tissue mass arising from high up in the sigmoid colon.

    A biopsy of the mass was most consistent with a the diagnosis of a dermoid ectodermal malignancy.
    After a central line port was placed, she tolerated the first cycle of chemotherapy well, and was to be followed closely.

    05-18-09Figure76SecondPrimaryCancerCT.jpg
    Figure 76 – Axial images from a computed tomography exam of the abdomen and pelvis perfomred with intravenous and oral contrast demonstates a large, ill-defined, heterogenous and necrotic mass arising from and filling the pelvis and extending up into the abdomen (lower image) that is associated with ascites and metastases to the liver and to the peritoneum anterior to the liver (upper image).

    Discussion
    About 12,400 children in the US are diagnosed with cancer each year, with 80% surviving. There are ~300,000 survivors of pediatric cancer in the US. Late complications of treatment may include problems with organ function, growth and development, neurocognitive function and academic achievement, infertility, and the potential for additional cancers, in addition to psychosocial consequences. It is estimated that 2/3rds of survivors will have at least one late-therapy complication and of those complications 1/4 will be life-threatening.

    In 2002 the Children’s Oncology Group published their Long-term Follow-up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers at http://www.survivorshipguidelines.org/. In 2009, the American Academy of Pediatrics published a clinical report supporting their use to assist in tailoring care based upon specific treatment-related risk factors.

    Learning Point
    Second primary cancers (SPCs, not a recurrance of the initial primary cancer) unfortunately are not unknown nor rare. As improvements in treatment and supportive care occur, survivorship from cancer has increased. Therapy, especially radiotherapy, has emerged as one of the causes of SPCs in childhood cancer survivors. One study found that the leading cause of death after 15 years of survivorship from pediatric cancer was a SPC.

    The Standardized Incidence Ratio (SIR) is a common statistical method used to describe incidence. The SIR is the ratio of the observed to the expected new cases of cancer. The expected number is based upon age-specific rates of cancer.

    Overall the SIR for all pediatric cancers was 5.9. This SIR is highest in the first 1-9 years of survivorship and decreases to 4.1 after 20+ years of survival. The SPC with the highest SIR for all pediatric cancers were acute myeloid leukemia, bone, gastrointestinal tract, lung, and pancreas.

    Acute lymphocytic leukemia (ALL) is the most common pediatric cancer accounting for ~25% of all malignancies. The SIR for ALL is 7.2 with the highest SIRs occurring in the 0-5 year survivorship group and decreasing to an SIR of 2.3 in the 11-15 years survivorship group. The SPC with highest SIR were a following ALL were acute non-lymphocytic leukemia and central nervous systems malignancies.

    Questions for Further Discussion
    1. What are the acute and long-term complications of chemotherapy?
    2. What are the acute and long-term complications of radiotherapy?

    Related Cases

    To Learn More
    To view pediatric review articles on this topic from the past year check PubMed.

    Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

    Information prescriptions for patients can be found at MedlinePlus for these topics: Soft Tissue Sarcoma and Cancer in Children.

    To view current news articles on this topic check Google News.

    To view images related to this topic check Google Images.

    Lawless SC, Verma P, Green DM, et al. Mortality Experiences Among 15+ Year Survivors of Childhood and Adolescent Cancers. Pediatr Blood Cancer. 2007;48:333-338.

    Krueger H, McLean D, Williams D. Prevention of Second Pediatric Cancers. Prog Exp Tumor Res. Basil, Switzerland. Karger. 2008:40:122-134.

    American Academy of Pediatrics Section on Hematology/Oncology. Children’s Oncology Group. Long-term Follow-up Care for Pediatric Cancer Survivors. Pediatrics 2009 123: 906-915.

    ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients’ is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    4. Patient management plans are developed and carried out.
    7. All medical and invasive procedures considered essential for the area of practice are competently performed.
    8. Health care services aimed at preventing health problems or maintaining health are provided.
    9. Patient-focused care is provided by working with health care professionals, including those from other disciplines.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Practice Based Learning and Improvement
    13. Information about other populations of patients, especially the larger population from which this patient is drawn, is obtained and used.
    14. Knowledge of study designs and statistical methods to appraisal clinical studies and other information on diagnostic and therapeutic effectiveness is applied.

  • Interpersonal and Communication Skills
    19. The health professional works effectively with others as a member or leader of a health care team or other professional group.

  • Systems Based Practice
    24. Cost-effective health care and resource allocation that does not compromise quality of care is practiced.

    Author
    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital

  • What Causes Bromhidrosis?

    Patient Presentation
    A 14 month-old female came to clinic with a complaint of body odor. The parents state that it did not occur when she was first born, but started sometime in the next few months. They state that they can bathe her daily in the evening and within 20-30 minutes she will begin to smell like sweat. The smell does not change. Parents states that it will be worse at certain times such as before a bath, but it does not change over the day, nor is it overpowering. Occasionally, other people will comment about the smell but usually it is not a problem. The parents deny having a problem with body odor themselves. The mother says that she wears perfume regularly because she likes the smell, not to cover up body odor. They eat an American diet without many spices, onions, garlic or other heavily scented foods. She had two ear infections in the past that she took amoxicillin for but was not on any medications currently. The parents deny her placing any foreign objects into an orifice, and also deny discharge or odor coming from an orifice.

    The past medical history reveals a healthy toddler, born at term, with a confirmed normal neonatal screening test that included tandem mass spectrometry.

    The family history is negative for any genetic or metabolic abnormalities. The parents deny consanguinity, nor a family history of miscarriages, early deaths or unexplained deaths.

    The review of systems was normal.

    The pertinent physical exam showed a happy toddler with growth parameters in the 75-90%. She did have a smell of sweat in general, that was not localizable. It was not from the urine in her diaper as when the diaper was separated from her in the room, the smell remained with the child. Her examination was normal including normal skin examination (especially all intertrigenous areas) and she was Tanner stage 1 for breast and hair.

    The work-up previously done by another health care provider included a normal complete blood count, thyroid function testing, urinalysis and lead. As the child showed normal growth and development with a normal neonatal screening, and no specific history of various causes, the diagnosis of idiopathic bromhidrosis was made. The natural history of the problem was discussed with the family. The parents were told they could try an antipersperiant that contains aluminum salts. They were instructed to apply only to non-broken skin and to not allow the child to ingest the material or inhale the antiperspirant. They were also offered the option of a consultation with a dermatologist. They wanted to try the antiperspirants first.

    Discussion
    Bromhidrosis or body odor is common in post-pubertal individuals because of apocrine gland secretions and increased exertion. It usually is self-limited or easily controlled. Sometimes it becomes more chronic, difficult to control and can affect a person’s quality of life. It is found in all races and genders.

    Eccrine secretory glands are found over the entire body service and assist in thermoregulation through sweating. Normally sweat is odorless. Softening of keratin and bacterial decomposition causes an odor. Certain foods, drugs/toxins or metabolic products may be secreted into the eccrine sections causing odor.

    Apocrine secretory glands are found in the axilla, breast, genital skin and periorbital and periauricular areas. They cause characteristic pheromonal odors. Apocrine bromhidrosis is the most common form of bromhidrosis. Bacterial decomposition of apocrine secretions changes the secretions into volatile acids and ammonia.

    Hyperhidrosis or excessive sweating may potentiate bromhidrosis. Potentially apocrine hyperhidrosis may contribute to bromhidrosis by creating a wet environment that facilitates bacterial overgrowth and also spreading of the secretions. However eccrine hyperhidrosis may also flush away secretions faster, therefore decreasing bromhidrosis.

    Learning Point
    Causes of bromhidrosis include:

    • Apocrine bromhidrosis and hyperhidrosis
    • Eccrine bromhidrosis
      • Foods
        • Alcohol
        • Curry
        • Garlic
        • Onion
      • Drugs
        • Penicillin
        • Bromide
      • Metabolic disorders
        • Phenylketonuria
        • Trimethyaminura (fish odor)
        • Sweaty feet syndrome
        • Cat odor syndrome
        • Isovaleric acidemia
        • Hypermethioninemia
    • Inadequate hygiene with bacterial overgrowth
      • Diabetes
      • Erythrasma
      • Intertrigo
      • Obesity
      • Trichomycosis axillaris
    • Foreign body in an orifice
    • Mistaken odors- tobacco smoke, perfume, asparagus smell of urine after ingestion

    Questions for Further Discussion
    1. What is the differential diagnosis for abnormal smelling urine?
    2. What is the differential diagnosis for halitosis?

    Related Cases

      Disease
      Bromhidrosis
      Sweat

    To Learn More
    To view pediatric review articles on this topic from the past year check PubMed.

    Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

    Information prescriptions for patients can be found at MedlinePlus for this topic: Sweat

    To view current news articles on this topic check Google News.

    To view images related to this topic check Google Images.

    MacFarlane A, Knass D, Beardwell CG,Shalet SM.
    Hyperhidrosis in acromegaly: effectiveness of topical aluminum chloride hexahydrate solution Br. Med. J.; VOL 2 ISS Oct 13 1979, P901-90.

    Rehmus W, Brown K. Bromhidrosis. eMedicine.Available from the Internet at http://emedicine.medscape.com/article/1072342-overview (rev. 2/16/2007, cited 3/25/09).

    ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients’ is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    4. Patient management plans are developed and carried out.
    5. Patients and their families are counseled and educated.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Practice Based Learning and Improvement
    13. Information about other populations of patients, especially the larger population from which this patient is drawn, is obtained and used.

  • Interpersonal and Communication Skills
    19. The health professional works effectively with others as a member or leader of a health care team or other professional group.

  • Systems Based Practice
    23. Differing types of medical practice and delivery systems including methods of controlling health care costs and allocating resources are known.
    24. Cost-effective health care and resource allocation that does not compromise quality of care is practiced.
    25. Quality patient care and assisting patients in dealing with system complexities is advocated.

    Author
    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital