Volume 12 Issue 3 - March 2014
                       
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Pediatric Breast Masses
     
  Breast masses in pediatric patients are uncommon and almost never (<0.2/100,00) due to cancer

  Ultrasound, which has good sensitivity in the developing breast, is the primary diagnostic imaging method

  Diagnostic mammography has limited use because of the density of the developing breast and its susceptibility to radiation damage

  MRI is primarily used for problem solving in cases of deep lesions and vascular malformations

  Biopsy is not recommended because of the potential for irreversible damage to the developing breast


Irregularities in Breast Development
Benign Findings
Malignant Tumors
Scheduling
Further Information
References

Although breast masses are uncommon in children, they are a source of concern, especially to parents, because of the fear of breast cancer. However, Surveillance Epidemiology and End Results (SEER) data from the United States from 1975 to 2010 shows that the incidence of cancer in girls under the age of 20 is <0.2/100,000.

Irregularities in Breast Development

Normal structures often account for breast complaints in prepubertal children and adolescents. Newborn infants commonly have subareolar nodules, which may be accompanied by nipple discharge. Such features are due to maternal hormones and nearly always self-limited. The presence of asymmetric breast buds in a prepubertal girl is also a source of concern, but this condition generally resolves.

Gynecomastia is a common condition in adolescent boys, typically occurring six months after the initial appearance of secondary sex characteristics. It normally resolves within two years of onset. However, pathologic gynecomastia can be caused by an increase in estrogen, a decrease in testosterone, or medication or drug use.

Imaging does not normally play a role in these irregularities; clinical examination and follow-up are sufficient. However, if a physical finding is concerning, ultrasound can exclude an underlying mass and confirm that the condition is due to normal-appearing breast tissue.

Ultrasound is also used to confirm normal-appearing breast tissue when accessory nipples or supernumerary breast tissue develop. These structures, which are most commonly seen in the axilla and are sensitive to hormonal influence much like the normal breast, develop from persistent fragments of the embryonic milk line, which extends from the axilla to the groin during embryonic development.

A prominent axillary lymph node in an otherwise healthy young patient can also raise concerns. Although it is most commonly due to inflammatory processes, clinical correlation and follow-up are appropriate. If questions remain, ultrasound imaging can examine nodal morphology and hilar vascular flow to confirm that the lymph node is benign.

Figure 1. Static focused ultrasound image in a 17-year-old girl demonstrates an anechoic well-circumscribed mass consistent with a benign simple cyst
Figure 1.Static focused ultrasound image in a 17-year-old girl demonstrates an anechoic well-circumscribed mass consistent with a benign simple cyst.


Benign Findings
Breast lumps in either boys or girls are nearly always due to benign masses. For this reason, biopsy should rarely be used to diagnose the condition because it can lead to irreversible damage.

Benign cysts are sometimes found in pediatric patients, and single cysts are more common than multiple ones. On ultrasound, they appear as anechoic structures, which may show posterior acoustic enhancement (Figure 1). Cysts are considered part of the spectrum of fibrocystic change.

The most common breast mass in girls is a fibroadenoma, a benign fibroepithelial tumor typically diagnosed between the ages of 15 and 17. Ultrasound imaging shows these tumors to have smooth circumscribed margins and a homogenous texture, and they are wider than tall (Figure 2). Since the likelihood of malignancy is <2%, they are safe to follow clinically. However, surgical excision is recommended if they rapidly enlarge or if there are atypical features, such as spiculated margins, microlobulations, angular margin, marked hypoechogenicity, or shadowing.

Trauma to the breast can also cause the development of a palpable mass, due to a hematoma or fat necrosis. These conditions can appear as an irregular hypoechoic mass on ultrasound, and a history of trauma can confirm the diagnosis. Over time, a hematoma involutes and resolves. Lumps from fat necrosis typically persist and can be followed clinically.

Mastitis and abscesses are most frequently seen in infants and adolescents of both sexes, although most are found in girls. Neonatal mastitis is rare and is thought to result from pathogens that access the hormonally stimulated breast tissue through the nipple. In adolescents, mastitis and abscesses are associated with skin infections, piercings, or lactation. Ultrasound is helpful in differentiating mastitis from abscess and can also be used to guide needle aspiration of abscess contents for laboratory culture or drainage purposes.

Figure 1. Static focused ultrasound image in a 15-year-old girl with a palpable lump reveals a solid mass with sonographic features consistent with a fibroadenoma
Figure 2.Static focused ultrasound image in a 15-year-old girl with a palpable lump reveals a solid mass with sonographic features consistent with a fibroadenoma.


Malignant Tumors
Malignant tumors are extremely rare in the pediatric population and account for <1% of breast masses. Phyllodes tumors are the most common primary breast malignancy in this age group. While most are benign, they do have malignant potential. Ultrasound and pathologic characteristics overlap with those of juvenile fibradenomas. However, ultrasound findings such as cysts, clefts and circumscribed masses (which may have posterior enhancement) with heterogeneous internal echotexture are suggestive of phyllodes tumor. In these cases, wide excision is recommended. Metastases are rare, but local recurrence is possible and does not alter the prognosis.

Secretory carcinomas are the most common type of invasive breast cancer in children. They are usually <3 cm, and ultrasound shows them as circumscribed masses with a pseudocapsule. Recommended treatment includes excision and sentinel lymph node biopsy. The prognosis is generally favorable.

The discovery of a breast mass in a child with predisposing genetic mutations, prior mantle radiation, or a known primary malignancy is suggestive of metastasis. In these cases, CT, MRI, or PET can often help define the extent of the disease.

Scheduling
Appointments for breast ultrasound can be made on ROE (mghroe.org) or by calling 671-726-8396. The examinations are performed at Mass General West Imaging in Waltham, Mass General Imaging in Worcester, Mass General/North Shore in Danvers and on the main campus of Massachusetts General Hospital in Boston.

Further Information
For more information regarding breast imaging in pediatric patients, please contact Mansi A. Saksena, MD, Breast Imaging, Massachusetts General Hospital (617-726-3093).

In addition to Dr. Saksena, we would like to thank Yiming Gao, MD, and Elizabeth A. Rafferty, MD, Breast Imaging, Department of Radiology, and Dr. Suzanne Coopey, MD, Breast Surgery, Massachusetts General Hospital, for their assistance and advice for this issue.


References

Chung EM, et al. (2009). From the archives of the AFIP: breast masses in children and adolescents: radiologic-pathologic correlation. Radiographics 29:907-31

Garcia CJ, et al. (2000). Breast US in children and adolescents. Radiographics 20:1605-12

Kaneda HJ, et al. (2013). Pediatric and adolescent breast masses: a review of pathophysiology, imaging, diagnosis, and treatment. AJR Am J Roentgenol 200:W204-12

Stavros AT, et al. (1995). Solid breast nodules: use of sonography to distinguish between benign and malignant lesions. Radiology 196:123-34

Surveillance, Epidemiology, and End Results Program. Cancer of the Breast (Invasive)

SEER Incidence and U.S. Death Rates, Age-Adjusted and Age-Specific Rates, by Race and Sex. http://seer.cancer.gov/csr/1975_2010/browse_csr.php?sectionSEL=4&pageSEL=sect_04_table.12.html#table2. Accessed February 10 2014.





©2014 MGH Department of Radiology

Janet Cochrane Miller, D. Phil., Author
Raul N. Uppot, Editor


 

 

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