Flame-shaped breast | Radiology Signs

Answer:

The flame-shaped or nodular pattern is a fan-like subareolar density that is centred on the nipple and radiates posteriorly into the surrounding fat, with its margins blending imperceptibly into the fat rather than forming a discrete mass. It is the appearance of florid gynecomastia, typically within the first year of onset, and is one of three recognised patterns. The dendritic pattern is a spiculated, branching subareolar density representing the fibrotic phase of long-standing disease, usually after a year, and it is the pattern most easily mistaken for carcinoma. The diffuse glandular pattern resembles a heterogeneously dense female breast and is associated with exogenous oestrogen. The features that distinguish gynecomastia from male breast carcinoma are position and margin: gynecomastia is symmetric about the nipple, has no true mass and no distortion, whereas carcinoma is typically eccentric to the nipple, forms a discrete mass with irregular or spiculated margins, and may show microcalcifications, skin or nipple retraction and axillary adenopathy. Ultrasound is used to problem-solve, showing a subareolar hypoechoic flame-shaped or nodular fibroglandular region without a discrete mass. The underlying cause should be sought clinically, since gynecomastia reflects an altered oestrogen to androgen ratio from puberty, senescence, hepatic or renal failure, hypogonadism, testicular or adrenal tumours and a long list of drugs including spironolactone, digoxin, cimetidine and antiretrovirals.

Why is it called so?

The subareolar tissue fans out from the nipple into the fat with tapering, feathered margins, resembling a flame.

Pathophysiology

Gynecomastia is proliferation of the ductal and stromal components of the male breast driven by an increase in the ratio of oestrogen to androgen activity. In the early florid phase there is ductal epithelial hyperplasia with a loose, oedematous, highly vascular periductal stroma, which is why the tissue is soft, tender and blends into the surrounding fat, giving the flame-shaped density. If the stimulus persists beyond about a year the stroma becomes densely fibrotic and hyalinised and the ducts branch within it, producing the spiculated dendritic pattern. Because ductal proliferation is centred on the nipple where the ducts converge, the process is always subareolar and symmetric about the nipple, which is the anatomical basis for the key distinction from carcinoma.

Alternative names: Nodular gynecomastia pattern; fan-shaped subareolar density

Other associated named signs: Dendritic pattern and diffuse glandular pattern of gynecomastia

References

1. Lattin GE Jr, Jesinger RA, Mattu R, Glassman LM. From the radiologic pathology archives: diseases of the male breast: radiologic-pathologic correlation. Radiographics. 2013;33(2):461-89. PMID: 23479708.