Evaluation of breast calciﬁ cations

Various patterns of calciﬁ cations occur in the breast; some benign, some malignant. A knowledge of these patterns on mammography helps in accurate interpretation and management


Introduction
MicrocalciÞ cations can be the early and only presenting sign of breast cancer. Mammography is used worldwide to detect microcalciÞ cations. Hence, with the help of mammography, we can not only diagnose cancer in a nonpalpable stage but can also detect the extent of the disease. It is very essential to perform a proper evaluation of various calciÞ cations to decide whether they are benign or malignant. A biopsy can be avoided if the calciÞ cations appear absolutely benign on mammography and the patient can be followed-up with annual screening mammography.
In 1913, a German surgeon, Solomon, reported the presence of microcalciÞ cations in the radiographic examination of a mastectomy specimen. In 1949, Leborgne, a radiologist, postulated that the presence of microcalciÞ cations may be the only mammographic manifestation of a carcinoma. [1] Since then, all radiologists have made active eff orts to look for microcalciÞ cations in mammograms and this in turn over the years has resulted in a signiÞ cant improvement in the resolution and performance of the mammography machines.
To detect microcalcifications efficiently, a good mammography machine should have: i) dedicated mammography grids, ii) a small focal spot and iii) a proper source image distance In addition, the following are necessary: i) MagniÞ cation. Every area of microcalciÞ cations should be magniÞ ed. ii) Proper processing of the mammography Þ lms should be performed, with longer processing times as compared to conventional radiography. iii) The use of a magnifying glass, which helps in bett er visualization, is a must. iv) A dedicated mammography viewing box (more than 3000 nit) should be used. v) There should be very litt le (<50 lux) ambient light in the room. vi) A computed-aided diagnosis (CAD) system is useful when evaluating a large volume of examinations, although CAD systems may sometimes fail to pick up amorphous calciÞ cations. [2] Full-Þ eld digital mammography machines are bett er than film-screen mammography machines for diagnosing microcalciÞ cations. High-resolution computer radiography (CR) machines cannot detect microcalciÞ cations effi ciently. [3] Once calciÞ cations are detected, they have to be described and categorized according to the lexicon mentioned in BI-RADS (Breast Imaging Reporting And Data System) so that the radiologist, the surgeon and the pathologist share a common language. BI-RADS, developed by the American college of Radiology, is followed worldwide to describe and categorize breast abnormalities.
In the chapter titled 'Lexicons' in the offi cial BI-RADS publication, calciÞ cations are described according to their appearance and distribution.  According to appearance Calcifications that are typically benign are described as follows: [5] Eggshell or rim-like calciÞ cations: These are thin, round, rimlike calciÞ cations oft en seen in the walls of cysts or in fat necrosis [ Figure 1].
Vascular calciÞ cations: These are also described as railroad track calciÞ cations, showing a linear conÞ guration, either singly or in parallel pairs [ Figure 3]. When small, single and linear, these calciÞ cations should be diff erentiated from malignant calciÞ cations.
Large, rod-like calciÞ cations or secretory deposits: These are due to secretory disease. The calciÞ c foci are thick and follow the ducts, toward the nipple [ Figure 4].

Milk of calcium:
These are seen as tiny, teacup-shaped calciÞ cations, situated within small cysts on the lateral  view [ Figure 5]. Sometimes, the small, rounded soft -tissue shadow of the cyst itself is also appreciated.
Lucent-centered calciÞ cations: These are rounded calciÞ cations with a lucent center usually representing dermal calciÞ cations [ Figure 6A]. Larger calciÞ cations with lucent centers may be due to oil cysts/fat necrosis and may follow surgery or trauma [ Figure 6B].

Calcifi cations that are of intermediate concern
Amorphous calcifications: These are very tiny, hazy calciÞ cations [ Figure 7] and are oft en diffi cult to pick up on CR machines. rod-like calciÞ cations and are typically seen in malignancy [ Figure 8].

Calcifi cations that are highly suspicious for malignancy
Pleomorphic calciÞ cations: These are microcalciÞ cations of varying shapes and sizes [ Figure 9].

According to distribution
Grouped or clustered: These are five or more than five calciÞ cations seen in a small area of 1 cm 3 [ Figure 10] and may be seen in benign or malignant conditions. If the cluster is a loose cluster (<10/cm 2 ), it is more likely to represent a benign condition, whereas a compact cluster (>20/cm 2 ) is more likely to be due to malignant disease. [6] Linear, segmental: These are suspicious calciÞ cations arranged in a line or showing a branching patt ern, suggesting deposits in a duct [ Figure 11]. They tend to be distributed in a linear manner because most common malignancies are ductal, beginning in the terminal ducts.
Regional: CalciÞ cations are seen in a large volume, not necessarily conforming to a duct; more likely to be benign.
Diff use or scatt ered: These calciÞ cations are seen all over the breast and may be bilateral [ Figure 12]. They are almost always benign.
In conclusion, with the help of morphology and distribution, calciÞ cations can be categorized into benign, of intermediateconcern, and malignant types. It would be more appropriate to categorize them with the help of BI-RADS into 2, 3, 4 and 5. [7] The egg shell, popcorn, lucent-centered, dermal, vascular calcifications, milk of calcium and scattered calciÞ cations are deÞ nitely benign and can be categorized as BI-RADS 2. They do not need biopsy or follow-up.
Those of intermediate concern can be categorized into 3 and should be closely monitored. Pleomorphic and castingtype calciÞ cations are categorized as BI-RADS 4 or 5 and a biopsy is recommended. In case follow-up is advised, it should be kept in mind that some microcalciÞ cations, sometimes even of DCIS , can remain unchanged for years. Some calciÞ cations are even known to resolve. [8]