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2007 ACR Diagnostic Radiology In-Training Exam Rationales

Section VII Breast Radiology 139. You are shown a left MLO view and spot compression view of the left breast (Figures 1A and 1B). No definite abnormality was seen on the CC views. What is the MOST LIKELY diagnosis? A. Ductal carcinoma in situ B. Radial scar C. Invasive lobular carcinoma D. Medullary carcinoma RATIONALES:

A. Incorrect. Ductal carcinoma in situ usually presents as calcification and does not usually cause distortion unless there is an invasive component.

B. Incorrect. A radial scar usually has a dark center with radiating lines as opposed to the image, which has a white center due to the presence of a mass. Usually a radial scar is visualized on both views.

C. Correct. Invasive lobular carcinoma is commonly seen on one view only or a least best visualized on one view. It is the hardest cancer to detect on mammography because it grows one cell at a time. It most commonly presents as an area of distortion or spiculation. The size is often difficult to measure on mammography and ultrasound.

D. Incorrect. Medullary carcinoma typically presents as a round mass, which grows rapidly.

References: Ikeda, Debra. “Breast Imaging” pp. 97-99.


140. You are shown a screening right MLO (Figure 2A) and magnification views in the MLO (Figure 2B) and CC (Figure 2C) projections. Which is the MOST appropriate BI-RADS code? A. Category 0 B. Category 2 C. Category 3 D. Category 4 RATIONALES: B. Correct. Hamartomas are unusual circumscribed benign breast lesions composed of variable amounts of fat, glandular tissue, and fibrous connective tissue. The classic mammographic appearance is virtually diagnostic. The lesion is circumscribed and contains both fat and soft-tissue density surrounded by a thin radiopaque capsule. When diagnostic features are present, routine annual mammography is appropriate and this should be coded Bi-RADS category 2. . References: Basset. Diagnosis of Diseases of the Breast. 2nd ed. Elsevier Saunders Co., Philadelphia, PA. 2005.


141. You are shown a T2-weighted (Figure 3A) and T1-weighted (Figure 3B) post contrast subtraction sagittal MRI of a 45-year-old woman. What is the MOST LIKELY diagnosis? A. Fibroadenoma B. Lipoma C. Lobular carcinoma D. Simple Cyst RATIONALES: Figure 1A, T2 weighted imaging, shows a well circumscribed mass of homogeneous high signal intensity. Figure 1B shows the same mass to “drop out” on the subtraction image. No evidence of contrast enhancement is seen within or surrounding the mass. A. Incorrect. On MRI imaging of the breast, fibroadenomas are predominantly solid with variable enhancement. This mass is fluid filled and has no enhancement. B. Incorrect. Lipomas should follow fat signal on both T1 and T2 weighted imaging. No high signal would be seen on either image. C. Incorrect. Breast cancers are typically solid with irregular margins and have marked enhancement. While imaging characteristics of breast cancer are variable, a well circumscribed fluid filled mass is not characteristic for breast cancer. D. Correct. This well circumscribed fluid filled mass is classic for a benign simple cyst. References: Jackson VP. The Radiologic Clinics of North America, Breast Imaging. November 1995 Volume 33, Number 6.


142. You are shown an MLO image (Figure 4A) as well as a magnification image (Figure 4B) and an ultrasound image (Figure 4C) of the inferior right breast. Which one of the following is the MOST LIKELY diagnosis? A. Silicone granuloma B. Invasive ductal carcinoma C. Fat Necrosis D. Fibroadenoma RATIONALES:

A. Correct. The mammogram image shows a well circumscribed dense mass inferior and anterior to the breast implant with additional dense material adjacent to the implant itself. US show a classic hyperechoic mass with snowstorm appearance. B. Incorrect. While breast cancer lesions can be well circumscribed on mammogram and US, most invasive ducal carcinomas are of decreased echogenicity on US and would typically have posterior shadowing as opposed to a snowstorm appearance. C. Incorrect. Fat Necrosis may appear as a mass on well circumscribed mass on mammogram. They may also have increased echogenicity on US. However, given the snowstorm appearance on US, density of mass on mammogram and the proximity to the implant make silicone granuloma more likely D. Incorrect. Fibroadenomas may be well circumscribed on mammogram and US but are typically homogeneously hypoechoic at US.

References:

1) Stavros, AT. Breast Ultrasound. Lippincott Williams & Wilkens.

Philadelphia, PA. 2004.

2) McGahan JP, Goldberg BB. Diagnostic Ultrasound A Logical Approach.

Lippincott-Raven. Philadelphia, PA. 19


143. You are shown a screening MLO mammogram (Figure 5A) and the same view taken 1 year later (Figure 5B). What should be recommended next? A. Ultrasound examination B. Additional mammographic images C. 6-month follow up D. Stereotactic biopsy RATIONALE A. Incorrect. The increased density in the upper aspect of the right breast may not be a true finding and requires spot compression views of the breast to see if it persists. Ultrasound evaluation without knowing the location of the lesion is of limited usefulness and should not be the preliminary workup. B. Correct. Additional mammographic workup should be performed including spot compression views to see if the area of increased density persists and if so triangulation to localize the finding on the craniocaudal view. C. Incorrect. When a new finding is seen on mammography it requires a workup mammographically and with a possible ultrasound before it is placed into a BIRADS™ 3 category. D. Incorrect. Before a biopsy should be considered the finding needs to be authenticated. A mammographic workup is required.


144. You are shown a right straight lateral (90 degree) magnification view (Figure 6). Which one of the following is the MOST LIKELY diagnosis? A. Invasive lobular carcinoma B. Ductal carcinoma in situ C. Sclerosing Adenosis D. Milk of calcium A. Incorrect. The most common presentations of invasive lobular carcinoma are a spiculated mass, an ill-defined or obscured mass, and architectural distortion. Occasionally, lobular carcinomas are diffusely infiltrating and may show only subtle findings on mammography. B. Correct. Ductal carcinoma in situ (DCIS) is usually detected on mammography, with calcifications being the mammographic hallmark. The calcifications are typically fine, linear, discontinuous, and branching, often in a ductal distribution. C. Incorrect. Adenosis is an abnormality of the lobules. Mammographically, the findings are often nonspecific and include diffuse ill defined nodular densities or multiple round or punctate calcifications. This should be considered a histologic diagnosis rather than a typical imaging diagnosis. D. Incorrect. Calcifications of milk of calcium have a layering appearance or crescent shape on horizontal beam (straight lateral) views. References: Basset. Diagnosis of Diseases of the Breast. 2nd ed. Elsevier Saunders Co., Philadelphia, PA. 2005.


145. Which quality control test must be performed DAILY? A. Phantom image evaluation B. Repeat analysis C. Processor QC D. Darkroom fog A. Incorrect. Evaluation of the phantom image should be performed at least weekly but is not required to be performed on a daily basis. B. Incorrect. The repeat analysis should be performed quarterly. C. Correct. Processor QC should be performed daily at the start of the workday before any patient films are put through the processor. D. Incorrect. Darkroom fog should be tested semiannually. 146. Increased dynamic range in digital mammography as compared to screen-film mammography results in which of the following? A. Increased temporal resolution B. Increased contrast resolution C. Reduced spatial resolution D. Radiation dose is decreased A. Incorrect. Temporal resolution is not affected by increased dynamic range. B. Correct. Different exposure levels mapping to a wider range allows for increased contrast in a digital image. C. Incorrect. increased dynamic range does not affect spatial resolution D. Incorrect. increased dynamic range does not affect radiation dose References: Mahesh M, AAPM/RSNA Physics Tutorial for Residents: Digital Mammography: An Overview, RadioGraphics 2004; 24:1747–1760


147. In film-screen mammography, film performs multiple functions that are coupled together. In digital mammography, these same functions are decoupled so that each may be optimized independently. Which of the following are the multiple functions? A. Image acquisition, scatter rejection, and archive B. Image acquisition, display, and magnification C. Image acquisition, display, and archive D. X-ray absorption, scatter rejection, and display RATIONALES: A. Incorrect – scatter rejection is accomplished by a grid B. Incorrect – magnification can not be accomplished with film alone C. Correct D. Incorrect – x-ray absorption is accomplished by a phosphor screen, scatter rejection is accomplished by a grid References: Mahesh M, AAPM/RSNA Physics Tutorial for Residents: Digital Mammography: An Overview, RadioGraphics 2004; 24:1747–1760


148. Concerning nipple discharge, which of the following statements is TRUE? A. Discharge associated with breast cancer usually arises from a single duct. B. Intraductal papillary carcinoma is the most common cause of bloody discharge. C. Green discharge is suspicious for underlying malignancy. D. Galactography is used to distinguish benign from malignant discharge. A. Correct. Benign nipple discharge usually arises from multiple ducts, whereas nipple discharge from a papilloma or DCIS usually occurs from a single duct.

B. Incorrect. The most common mass producing bloody nipple discharge is a benign intraductal papilloma. Only approximately 5% of women with bloody nipple discharge are found to have malignancy at biopsy. C. Incorrect. Nipple discharge is of particular concern if it is spontaneous and from a single duct, or if the discharge is clear or bloody.

D. Incorrect. Galactography is more sensitive than mammography in the detection of intraductal lesions but it cannot accurately distinguish between benign and malignant findings. References:

1. Ikeda DM. The Requisites: Breast Imaging. Elsevier Mosby, Philadelphia, PA. 2004.

2. Bassett LW, Jackson VP, et al. Diagnosis of Diseases of the

Breast. Elsevier Saunders, 2nd Edition, Philadelphia, PA 2005.


149. Concerning fibroadenomas, which of the following statements is TRUE? A. Posterior acoustic enhancement is diagnostic on ultrasonography. B. Calcifications typically develop centrally within the mammographic mass. C. Dark internal septations and persistent enhancement are characteristic findings on MRI. D. The presence of cystic spaces on ultrasonography indicates malignant degeneration. A. Incorrect. On ultrasound, they may demonstrate posterior acoustic enhancement or shadowing. Neither feature is diagnostic. B. Incorrect. As the fibroadenoma ages, it may become sclerotic and less cellular. Popcorn like calcifications subsequently develop at the periphery of the mass and ultimately, the entire mass may be replaced by dense calcification. C. Correct. On MRI, fibroadenomas have the classic appearance of an enhancing oval or lobulated mass with well circumscribed borders. They contain dark internal septations with a gradual initial enhancement rate and a persistent enhancement curve.

D. Incorrect. Fibroadenomas are typically hypoechoic on sonography but may contain cystic spaces. The presence of cystic spaces does not necessarily indicate malignant degeneration. References: 1. Ikeda DM. The Requisites: Breast Imaging. Elsevier Mosby, Philadelphia, PA. 2004.


150. Which one of the following risk factors places a patient at the HIGHEST risk for developing breast cancer? A. Moderate/florid ductal hyperplasia B. Lobular carcinoma in situ C. Sclerosing adenosis D. Atypical ductal hyperplasia RATIONALES: A. Incorrect. Moderate hyperplasia raises risk slightly for breast cancer. B. Correct. High risk for breast cancer with lobular carcinoma insitu( 8-10X increase) C. Incorrect. Moderate increased risk for this. D. Incorrect. Moderate increased risk for this. References: Cardenosa, Gilda. “Breast Imaging Companion” second edition. Pp. 3-4. The following cause a high risk for breast cancer: Aypical ductal hyerplasia with positive family history of a first degree with breast cancer, LCIS and well-differentiated ductal carcinoma insitu. High risk means 8-10 x increased risk. Other factors as mentioned in question increase risk on slightly or moderately.


151. Which of the following ultrasonographic findings is MOST commonly associated with a galactocele? A. Oval mass B. Anechoic mass C. Mass with angular margins D. Mass with microlobulated margins RATIONALES: A. Correct. A galactocele is usually oval to round in shape. B. Incorrect. A galactocele will have internal debris and be hypoechoic or mixed echogenicity on ultrasound. C. Incorrect. Angular margins are associated with malignancy. D. Incorrect. A microlobuated mass infers malignancy and galactocele is usually oval and smooth. References: Ikeda, Debra. “ Breast Imaging” pp. 128-129. A galactocele is usually low density on mammography and has internal echoes on ultrasound with smooth borders and configuration. It can have through transmission of sound or shadowing. When aspirated white milky fluid is obtained. 152. Which of the following findings on MRI is MOST suggestive of a malignant breast mass? A. Mild enhancement curve B. Enhancement washout curve C. Homogeneous enhancement D. Dark internal septations RATIONALES: A. Incorrect. Breast cancer will enhance brightly with marked uptake not mild enhancement. B. Correct. Washout curves are highly suspicious of malignancy. C. Incorrect. Breast cancer will enhance heterogeneous reflecting areas of varied activity and necrosis. D. Incorrect. Septations are usually not present and if present will be bright. References: Morris, Elizabeth and Laura Leiberman. “Breast MRI” pp. 173-183. ACR Lexicon for Breast MRI. A breast cancer will enhance brightly with rapid uptake and rapid washout of contrast. The enhancement pattern will be heterogeneous representing areas of varied activity and possible necrosis. Septations are usually not present and if present will enhance and be bright.


153. Using ACR Accreditation criteria for clinical image evaluation, which is recommended for pectoralis muscle? A. A concave shape on the MLO view B Visible on the CC view C. Equal in size on the CC and MLO views D. Extends to the level of the posterior nipple line RATIONALES: A. Incorrect. The pectoral muscle should have a convex shape on the MLO view. B. Incorrect. The pectoral muscle does not have to be demonstrated on the CC view. There should be as much tissue on the CC in relation to the MLO within 1 cm. C. Incorrect. The pectoral muscle will not be the same size on both views and usually is much smaller on CC view. D. Correct. The pectoral muscle should extend to the posterior nipple line on the MLO view. References: Cardenosa, Gilda “Breast Imaging Companion” pp. 100-109. The ACR criteria state the requirements for correct positioning of the both the CC and MLO views. The MLO view should have a convex pectoral muscle and extend to within 1 cm of the PNL. The inframammary fold should be opened and the nipple in profile. The breast tissue should be adequately compressed. On the CC view, there should be at least at much tissue within 1 cm as on the MLO.


154. Which one of the following is an indication for evaluation of the breast with contrast-enhanced MRI? A. Suspected implant rupture B. Extent of tumor in dense breasts C. Cystic masses in both breasts D. Cloudy discharge with negative galactogram RATIONALES: A. Incorrect. Contrast is not necessary for evaluation of implant rupture. Images with fat saturation and silicone and water saturation would be helpful. B. Correct. Contrast can help to locate other foci of tumor and more accurately evaluate tumor size as well as lymph node involvement. C. Incorrect. Cystic masses do not require the use of contrast but can be detected by T1 and T2 imaging. D. Incorrect. White discharge is usually benign. Bloody or clear discharge could be evaluated with MRI and contrast may be helpful. References: Ikeda, Debra. “Breast Imaging” pp. 210-213.


155. Regarding Paget’s disease, which one of the following is CORRECT? A. It is characterized by bleeding and ulceration of the nipple-areolar complex. B. It is classically diagnosed as an irregular mass on mammography. C. It results from a chronic irritation of the nipple-areolar complex epidermis. D. It is typically treated with partial breast irradiation. RATIONALES: A. Correct. Paget’s disease is characterized by a chronic erythematous, ulcerating and bleeding nipple-areolar complex. These findings may cause itching, bleeding or a burning sensation of the nipple. B. Incorrect. Paget’s is classically diagnosed when there is a high degree of clinical concern based on physical exam findings. This is confirmed with skin biopsy. While, mammographic findings may include skin or nipple thickening, calcifications or a retroareolar mass, as many as one third of all patients have no mammographic finding. C. Incorrect. Paget’s may appear similar to dermatitis with chronic inflammation but the disease results from the extension of malignant cells up thru the ducts to the nipple surface epithelium. D. Incorrect. Depending on the extent of involvement, treatment routinely includes surgery. Surgical options include: a breast conserving procedure if the area of involvement is small and there is little or no invasive component or a total mastectomy with or without axillary sampling if the mass is larger and has a significant invasive component. Breast irradiation as a single method of treatment is not considered adequate or appropriate treatment and should be considered only in conjunction with a definitive surgical procedure. References: 1. Bassett LW, Jackson VP, Fu KL, Fu YS. Diagnosis of Diseases of the Breast. 2nd Edition. Elsevier Saunders, Phildelphia, PA. 2005, pp 527-528. 2. Powell DE; Stelling CB. The Diagnosis and Detection of Breast Disease. Mosby, St. Louis, MO. 1994, pp 334.


156. Approximately what percentage of breast cancers occur in men? A. 1% B. 5% C. 10% D. 15% RATIONALES: A. Correct. Given data from the American Cancer Society, it is estimated that 1720 new cases of male breast cancer will be diagnosed in 2006. This is in contrast to the estimated 212,900 new cases of female breast cancer that will be diagnosed in the same time period. This suggests that approximately one out of every 100 new breast cancers will be in a male patient. 157. Concerning invasive lobular carcinoma, which one of the following is TRUE? A. The most common mammographic finding is a dominant mass with calcifications. B. It accounts for approximately 20% of all breast cancer cases. C. An ill-defined hypoechoic mass on ultrasonography is typical. D. It is easily distinguished from invasive ductal carcinoma on mammogram and ultrasound. RATIONALES: A. Incorrect. Invasive lobular carcinoma (ILC) is probably the most difficult type of breast cancer to identify using any imaging modality. This type of breast cancer is most commonly seen on mammogram as a spiculated mass or area of architectural distortion. However, many ILC tumors are subtle and are difficult to detect due to a diffusely infiltrative nature. Calcifications are not typical but may occur in up to 20% of cases. B. Incorrect. ILC accounts for approximately 10% of all breast cancer cases and is the second most common type after invasive ductal carcinoma (IDC) not otherwise specified. C. Correct. ILC is usually seen on ultrasound as an ill defined solid mass of decreased echogenicity. There is often considerable post tumoral shadowing. D. Incorrect. Unfortunately, there are no specific distinguishing factors between ILC and IDC on any imaging modality including mammogram, US, MRI and PET. However, the overall subtle nature of ILC makes it one of the most difficult tumors to detect. References:

1. Bassett LW, Jackson VP, Fu KL, Fu YS. Diagnosis of Diseases of the Breast. 2nd Edition. Elsevier Saunders, Philadelphia, PA. 2005.


2. Cardenosa. Breast Imaging Companion. 2nd. Lippincott Williams & Wilkins Philadelphia, PA. 2001

Powell DE; Stelling CB. The Diagnosis and Detection of Breast Disease. Mosby, St. Louis, MO. 1994. 158. Concerning complex sclerosing lesions (radial scars), which one of the following is TRUE? A. They are typically related to prior trauma or an invasive surgical procedure. B. They usually present as palpable masses at clinical exam. C. Mammographic features include a circumscribed mass with a central lucency. D. They have been shown to be associated with tubular carcinoma and atypical hyperplasia. RATIONALES: A. Incorrect. Complex sclerosing lesions, radial scars, are not related to prior trauma or surgery and are not in fact “scars” at all. The etiology of radial scars is unknown. B. Incorrect. Radial scars are typically seen on mammography or are incidentally found at excisional biopsy but are not characteristically palpable on physical exam C. Incorrect. Classic mammographic features of a complex sclerosing lesion include a spiculated mass with a central lucency. This is often considered to represent entrapped fat. D. Correct. Radial scars do have an association with tubular carcinoma, invasive ducal carcinoma, DCIS and atypical hyperplasia. Because of this relationship and to avoid sampling error at core needle biopsy, it is often felt that surgical excision is required to exclude any related malignancy. References:

1. Bassett LW, Jackson VP, Fu KL, Fu YS. Diagnosis of Diseases of the Breast. 2nd Edition. Elsevier Saunders, Philadelphia, PA. 2005.

2. Cardenosa. Breast Imaging Companion. 2nd edition. Lippincott Williams & Wilkins Philadelphia, PA. 2001


159. Regarding phyllodes tumor, which one of the following is TRUE? A. Benign and malignant phyllodes tumors can be distinguished using ultrasonography. B. Phyllodes tumors typically occur in women younger than age 40. C. Up to 15% of malignant phyllodes tumors will have lymphatic metastasis. D. Approximately 20% of all phyllodes tumors will recur locally after surgical excision. RATIONALES: A. Incorrect. Benign and malignant phyllodes tumors are indistinguishable on mammography and ultrasound. When small, there are also indistinguishable from fibroadenomas. If the mass is larger in size with an inhomogeneous echotexture and peripheral cystic spaces, the malignant variant may be suggested. B. Incorrect. Phyllodes tumors typically occur 10-20 years later than fibroadenomas with an age of presentation between 40 and 50. C. Incorrect. While less than 20% of malignant phyllodes tumors will metastasize, metastasis is classically via a hematogenous route to the lungs and bone. D. Correct. There is a high recurrence rate, 20% or greater, with phyllodes tumors. The borderline and malignant types have the highest rate of recurrence. Recurrence is more likely if surgical margin is less than 2 cm. References: 1. Harris JR, Lippman ME, Morrow M, Osborne CK. Diseases of the Breast. 2nd edition. Lippincott Williams & Wilkins, Philadelphia, PA. 2000.


160. Concerning tubular carcinoma, which is CORRECT? A. It has a less favorable prognosis than invasive ductal carcinoma. B. It is typically a well-circumscribed mass. C. Microcalcifications are frequently associated. D. It is commonly histologic grade 1. RATIONALES A. Incorrect. Tubular carcinoma has a more favorable prognosis than invasive ductal carcinoma. B. Incorrect. Tubular carcinomas are not typically well circumscribed. They are slow growing and have an irregular shape and are spiculated. C. Incorrect. Microcalcifications occur infrequently (10-15%) in tubular carcinoma.

D. Correct. Tubular carcinomas are well differentiated and nearly always grade1. 161. Concerning duct ectasia, which of the following is TRUE? A. It must be bilateral to make the diagnosis mammographically. B. The associated calcifications may contain internal lucencies. C. It carries an increased risk for breast cancer. D. It is associated with previous bacterial infection. RATIONALES A. Incorrect. In duct ectasia the secretions in the ducts often calcify, producing the typical secretory calcifications seen as rod like calcifications. These calcifications are commonly diffuse and bilateral but can be unilateral and more focal. B. Correct. The calcifications in duct ectasia can contain internal lucencies when the calcifications occur on the outside of the duct. C. Incorrect. Ductal ectasia does not increase a woman’s risk of breast cancer. D. Incorrect. Duct Ectasia is a chemical mastitis.

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