:::: FOR OUR REFERRING PHYSICIANS : NEWSLETTER :.

Invasive Lobular

Dear Colleagues:

Some breast cancers are notorious for their ability to be clinically and radiographically occult.  The potential for invasive lobular carcinoma to become advanced before it is suspected on clinical examination or routine screening mammography should be understood and respected by clinicians and radiologists.  Strategies for minimizing the risk of missing or delaying the diagnosis of this disease are important.  We hope you will find the enclosed report on invasive lobular carcinoma useful and interesting.

Should you have any questions pertaining to this subject or other breast-related concerns, please feel free to call me or my associates, Dr. Paul Meunier or Dr. Jane Bedell.

Sincerely,

G.W. Eklund, M.D., FACR

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THE BREAST CANCER YOU ARE MOST LIKELY TO MISS IN YOUR PRACTICE

G.W. Eklund, M.D., FACR
Medical Director
Pacific Breast Center

Breast cancer is a heterogeneous disease with one subtype, which represents only 10% to 15% of all breast cancers, accounting for the majority of malpractice claims for missed or delayed diagnosis of breast cancer.  The culprit is invasive lobular carcinoma, with behavioral and biological features that allow it to become extensive before becoming clinically or mammographically apparent.  Often invasive lobular carcinoma (ILC) is associated with vague clinical findings such as ambiguous thickening or induration, decreasing breast size or nonspecific symptoms of “pulling” sensations, “aching” or simply, “just feels different.” Mammographic findings vary from entirely normal-appearing tissue to spiculated masses.   Subtle areas of equivocal architectural distortion or increased density are often the only findings.  An uncommon, though characteristic, imaging finding is the so-called “shrinking breast.”  6% to 28% of invasive lobular carcinomas are bilateral.

The pathological findings explain the biological behavior of ILC. Clinical and mammographic findings of invasive breast cancer result from the infiltrative pattern and the effect on surrounding tissues.  Cancers that incite a dense desmoplastic reaction in the surrounding tissue are more likely to present as firm palpable masses or spiculated mammographic lesions that are difficult to mask.  ILC typically infiltrates through the normal tissues of the breast in loose strings of monomorphic cells that tend to elicit little or no surrounding desmoplasia.

Although not all ILC will be seen sonographically, ultrasound may be especially useful in resolving ambiguous clinical or mammographic findings.  ILC that has only subtle mammographic findings may appear as a highly suspicious hypoechoic mass with intense shadowing on ultrasound.

Strategies for minimizing the risk of delayed diagnosis of ILC

Understanding the behavior of this breast cancer “terrorist” provides a framework on which we can build our defenses and enhance opportunities to eradicate the threat before it has had time to do irreparable damage to the patient and her healthcare providers.

• Listen to the patient and respect her nonspecific breast complaints.
• Respect and document subtle or ambiguous clinical findings.
• Alert the breast imaging service to subtle or ambiguous clinical concerns.
• Be specific in defining the location of clinical concerns: o’clock position and distance from the nipple.
• Remember that patients sent for screening mammography are presumed to have “no clinical concerns” and that knowledge of vague or ambiguous clinical concerns often leads to the perception of vague or ambiguous imaging findings that leads to further workup that may reveal an early breast cancer.
• Don’t accept the report of “negative study” as a benign explanation of your clinical concern.
• Expect a breast imaging study report to indicate whether your clinical concern has or has not been explained.
• If your clinical concern has not been explained by a mammographic study, ask whether an ultrasound study was done or considered? If not, why not?
• Consult with and share your concerns with the breast imaging radiologist.
• Consider surgical consultation if there are ongoing clinical concerns that have not been explained by the imaging findings.

BIBLIOGRAPHY

• Physicians Insurers Association of America. PIAA Breast Cancer Study. Rockville, MD: Physician Insurers Association of America; Spring 2002.

1. Physicians Insurers Association of America. Breast Cancer Study. Physicians Insurers Association of America, Washington, D.C. 1995.
2. Cardenosa G, Doudna CD, Eklund GW. Infiltrating lobular carcinoma: mammographic and ultrasound findings (abstr). AJR 1994; 162:217
3. Krecke, Grisvold JJ. Invasive lobular carcinoma of the breast: mammographic findings and extent of disease at diagnosis in 184 patients. AJR 1993; 161:957-960
4. Newstead GM, Baute PB, Toth HK. Invasive lobular and ductal carcinoma: mammographic findings and stage at diagnosis. Radiology 1992; 184:623-627