Doughnut-like appearance of chronic galactocele – A case report

INTRODUCTION

Breast changes during pregnancy and lactation reflect changes in the serum levels of estrogen, progesterone, and prolactin. Breasts become firmer, and there is a proliferation of glandular tissue in preparation for breastfeeding.^[1]

Galactoceles are cysts that develop within the breasts when milk in the ducts of the breast fails to travel outward, becoming stagnant. This ultimately produces a fatty or milk-containing lump. The timing of cyst development varies from when a woman ceases breastfeeding but may also develop anytime from the third trimester of pregnancy through the beginning of lactation.^[2]

Galactoceles may present as painless rounded swellings, either unilaterally or bilaterally. These are located along the milk line extending from the axilla to the groin.

It can have myriad appearances. The differential diagnosis includes other diseases of the breast, like cysts, fibroadenomas, abscesses, or even carcinomas. If not definitely benign on imaging, then further evaluation is recommended.

CASE REPORT

A 32-year-old woman presented to our mammography center, with an enlarged left breast and a palpable mass since one year. She started developing it when she was pregnant with her fourth child. The child is 2 years old now, and she has stopped breastfeeding for 2 months. The patient did not report a history of breast cancer in any of her first-degree relatives, and she did not have any other high-risk factors.

Physical examination revealed a large breast lump (approximately 10 cm × 10 cm) in her left breast, which was soft and mobile on palpation. Bilateral breast 2D mammogram (Mammomat Inspiration) with digital breast tomosynthesis [Figure 1a–b] was done. A large, circumscribed, round, hyperdense mass was noted in the left breast. It was a round, circumscribed, fat-containing lesion. Another small, fat-containing, hypodense round lesion was seen superior to it.

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Figure 1:

(a and b) Bilateral breast 2D mammogram CC views show enlarged left breast with central hypodense lesion surrounded by a relatively high density circular mass lesion – appearance likened to “bubbles”/“doughnut”/“tyre”/“meduvada.” CC: Craniocaudal.

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A medio-lateral (ML) [Figure 2] view was performed to look for a fat fluid level or change in the appearance of the lesion. However, no fat fluid level was noted.

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Figure 2:

(a and b) Left breast mammogram MLO and ML views revealed large well circumscribed round mass in left breast with “bubbles”/“doughnut”/“tyre”/“meduvada” appearance. No fat-fluid was noted even on true lateral view. MLO: Medio lateral oblique. ML: Medio lateral.

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On ultrasound, a hypoechoic circumscribed oval mass was seen in the left breast, predominantly in the lower inner quadrant, which showed some internal vascularity. It measured 14.7 cm × 5.6 cm × 12.1 cm in size.

A round, echogenic, circumscribed lesion was seen within it, which measured 6.2 cm × 4.1 cm × 5.6 cm in size. Another small, circumscribed, echogenic lesion was seen at its periphery superiorly, measuring 0.9 cm × 0.7 cm in size. However, no mobile echoes were seen within the mass [Figure 3a–d]. A lymph node with a thickened cortex was noted in the left axilla, measuring 2.4 cm × 1.2 cm in size, with a cortical thickness of 0.6 cm.

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Figure 3:

(a–d) Breast ultrasound with compound/panoramic views revealed a circumscribed hypoechoic mass with two echogenic lesions within it and mild internal vascularity on colour doppler. 1 and 2: Indicate anteroposterior and transverse measurements. + sign: Indicates the position of the cursor on screen while measurements.

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In view of the peculiar appearance of the lesion, minimal vascularity in the peripheral hypoechoic area, and a slightly prominent left axillary lymph node, an ultrasound-guided biopsy of the left breast mass was recommended. Under full aseptic precautions, ultrasound (USG) guidance, and local anesthesia, a core biopsy was done using a co-axial technique. The specimen was collected at first from the inner echogenic lesion. This disintegrated and made the clear formalin opaque. Then, a wide-bore needle was introduced through coaxial technique, and curdled milk was aspirated from the lesion [Figure 4]. Biopsies were taken from the peripheral part of the lesion and submitted for histopathology.

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Figure 4:

Curdled milk aspirated from the lesion with a wide bore needle.

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On histopathology, the specimen from the inner part revealed benign breast parenchyma with a dilated duct. Separate bits showing proteinaceous material and fat globules were seen [Figure 5a–b]. There was no evidence of malignancy.

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Figure 5:

(a) 20X, (b) 35X HPE of the inner part of the lesion revealed proteinaceous material with fat globules (black arrow). (HPE slide courtesy – Dr Anita Borges, Dr Vivek Parameshwar. Center for Oncopathology, Mumbai). HPE: Histopathological examination.

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The peripheral part of the lesion, on histopathological examination, revealed benign breast parenchyma with extensive hyalinization and a dilated duct [Figure 6a–b]. There was no evidence of malignancy.

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Figure 6:

(a) 1X, (b) 2X HPE of the peripheral part of the lesion revealed cores of hyalinised benign breast parenchyma (HPE slide courtesy – Dr Anita Borges, Dr Vivek Parameshwar. Center for Oncopathology, Mumbai). HPE: Histopathological examination.

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The final diagnosis was a chronic galactocele with intense surrounding hyalinization.

DISCUSSION

The breasts in a pregnant or lactating woman undergo the effects of hormones like estrogen, prolactin, and progesterone. There are changes in the ducts, and the lobules expand for milk secretion. If the accumulated milk remains in the duct for an extended period of time, a galactocele may begin to form.^[1]

Galactoceles are common lesions that account for 4%–5% of breast imaging and reporting data system (BIRADS) 4a lesions for which core needle biopsies are performed.^[3]

Factors that predispose to galactocele formation include difficulty in breastfeeding or if breastfeeding is contraindicated and breast milk is not emptied, as in phenylketonuria and classic galactosemia.^[4] Case reports of galactocele in male infants have been reported due to the effect of maternal estrogen on the infant breast.^[5,6]

Cases of galactocele with such peculiar appearance are not very frequently reported in the literature.^[7] The lesion itself is benign and usually asymptomatic. An appearance of chronic galactocele with surrounding hyalinized breast tissue, as seen in this case, has not been reported in literature.

Mammography has a limited role during pregnancy and lactation due to the diffuse increase in density of the breast parenchyma. Mammographic appearance of galactocele may vary due to suspension of emulsified tiny fat globules in a watery base as a heterogeneous mass with a fat fluid level. If infected, it may appear like a breast abscess. Chronic galactocele may appear as a true lipid cyst due to complete resorption of the water component.^[3] Sometimes, chronic galactoceles may also show calcifications.

Sonographic findings of a galactocele include a solitary, well-defined, anechoic lesion with thin, echogenic walls and some distal acoustic enhancement in the acute phase. Chronic cysts will show internal echogenic foci with acoustic shadowing as they age. A heterogeneously echoic, irregularly marginated collection is suspicious of abscess formation in a chronic galactocele and should be correlated clinically with signs such as redness, tenderness, and warmth.^[8]

Color Doppler investigation may be of some benefit in cases of galactocele. Complex cysts presenting as galactocele can be carefully differentiated from intracystic carcinoma or intraductal papilloma, as blood flow will be absent on the color Doppler in the case of galactocele. However, our case showed mild vascularity on Doppler in the peripheral hypoechoic component.

Management of galactocele is usually conservative.^[9] Ultrasound-guided fine-needle aspiration is both diagnostic and therapeutic in most cases.^[10]

Cyst resolution following aspiration can be a pathognomonic sign of a galactocele. It is suggested that the site of aspiration should be in a non-dependent location to prevent the formation of milk fistula, and cessation of breastfeeding is not necessary for the healing after aspiration.^[11,12] However, an excisional biopsy is recommended as the definitive treatment of the chronically obstructed duct if it is rapidly enlarging, if there is discordance in the triple assessment, or if the mass recurs after complete aspiration.^[13]

The differential diagnosis of galactocele^[14–17] includes breast cyst, hydatid cyst, breast abscess, fibrocystic changes, lactating adenoma, traumatic fat necrosis, hematoma, and hamartoma. A simple cyst is typically a well-defined, anechoic lesion with an imperceptible wall and posterior acoustic enhancement. A hydatid cyst would appear as a heteroechoic cyst with hydatid sand and daughter cysts within. A breast abscess would present clinically as a painful, tender, warm lesion with a heterogeneous appearance on ultrasound and moving pus echoes within.

CONCLUSION

Galactocele is a commonly seen, benign, and self-resolving disease of the breast. Large galactoceles may require drainage or excision. It can have myriad appearances on a mammogram and an ultrasound. The peculiar appearance of chronic galactocele due to surrounding hyalinization as seen in this case, has not yet been reported in literature and could be likened to bubbles/tires/meduvada/doughnuts. Images like these are imperative for the expansion of the knowledge base in breast radiology. This case is also presented here to highlight the importance of a complete workup in benign etiologies. A benign appearing lesions may harbor a sinister etiology and must undergo complete evaluation. Triple assessment is essential for a conclusive diagnosis.