Abstract
INTRODUCTION:
Lactating adenoma is the commonest benign breast lesion seen during pregnancy and puerperium. It is commonly seen in young primigravideous women in the second or third decade during the third trimester of their pregnancy. Occasionally, lactating adenoma is large and rapidly growing and must be differentiated from malignant breast masses that could be seen during pregnancy and lactation. The diagnosis is usually established by cytological and histopathological examination.
CASE PRESENTATION:
Here we have presented a rare case with huge lactating adenoma arising in the left breast of 38 years old Egyptian multiparous lady during lactation. Enucleation of the mass was done with good aesthetic outcome.
CONCLUSION:
The case we have presented was unique in its huge size and in being diagnosed in a multiparous lady and furthermore it was successfully treated by enucleation without any need for reconstruction.
Introduction
Lactating adenoma is a rare completely benign breast lesion that is also termed nodular lactational hyperplasia or lactational nodule. Despite being called lactational, it is more commonly seen during pregnancy than during lactation, therefore some authors preferred to call it breast tumor of pregnancy being the most common tumor occurring during pregnancy [1]. Other pregnancy associated breast lesions are fibroadenomas, breast infarcts and gigantomastia. Lactating adenoma was thought to be closely related but still clearly distinguishable from tubular adenoma which is usually not seen during pregnancy [1,2].
Lactating adenoma usually present as solitary (sometimes multiple), painless, well circumscribed, freely mobile, lobulated mass; and in many reports its size is usually small (around 3 cm in its greatest dimension) with tendency for self-regression [3,4]. Only few reports stated the occurrence of a huge or giant lactating adenoma [2,5]. The present case measured 27 cm × 18 cm clinically and 17 cm × 13 cm grossly and so it qualifies for the largest reported case of lactating adenoma (for timelines of the case, see Table 1).
Case presentation
A thirty-eight Egyptian multiparous lactating female was presented, at the authors’ service with a huge left breast mass. At the time of presentation, the patient was in the third month postpartum and was lactating only from the right breast with very few milk arising from the left breast. The patient stated that this mass started to appear as a small swelling in the left supra-areolar region, in the third trimester of her fifth pregnancy, with gradual onset and stationary course till delivery, however, the mass started to rapidly increase in size after delivery till it reached its present size.
On examination the mass was clinically 27 cm × 18 cm in its greatest dimensions and was occupying nearly the whole left breast especially the supra-areolar and retroareolar regions. There were no palpable axillary lymph nodes. The mass with associated with pain according to the patient’s own words and the overlying skin was dark, hyperpigmented and stretched; and showed an area of break down or non-healing ulcer 3 cm × 3 cm, which corresponds to the site of an incisional biopsy performed outside our center (Fig. 1).
The lesion was re-evaluated by revision of the slides of the previously performed incisional biopsy which revealed fibrocystic disease with lactational changes. Also ultrasound and mammography were done, the ultrasound revealed huge well defined mass occupying most of the left breast parenchyma, the mass showed mixed echogenicity with multiple variable sized areas of cystic changes and was given BIRADS 4b, and small reactive axillary lymph nodes. The mammography also revealed a large well defined high-density mass involving most of the left breast parenchyma with thickened overlying skin (Fig. 2).
We tried giving anti-prolactin therapy (Dostinex tablets) for three weeks as a medical treatment hoping to shrink the mass and also as a preparation for surgery in order to prevent potential milk fistula. After anti-prolactin therapy, milk production completely stopped from both breasts yet there was no regression in the mass size so enucleation of the mass under general anesthesia was contemplated together with excision of the ulcerated overlying skin (Figs 3 and 4).
The specimen received by the pathology laboratory measured 17 × 13 in its greatest dimensions. The mass was grossly greyish white in colour with brownish tan, having lobulated surface. The cut section was greyish white with cystic spaces. The microscopic examination revealed benign tumoral proliferation formed of proliferating breast ducts surrounded by scanty stroma and some ducts shows cystic dilatation and adenosis. The ducts are lined by inner cuboidal and outer myoepithelial layers, no atypical or malignant cells.
The evaluation of the esthetic outcome of our patient was good both subjectively and objectively, however the period of follow up is quite short and we are still following up our patient. (Fig. 5).
Discussion
Despite the name, Lactating adenoma is the most prevalent breast mass seen during pregnancy and it is less common during lactation. It is commonly seen in young primigravideous women in the second or third decade during the third trimester of their pregnancy [6]. Clinically, it is a challenge to differentiate lactating adenomas from other benign conditions that could be encountered during pregnancy such as fibroadenoma, breast infarcts, breast hamartoma and gigantomastia [2,7].
Particularly when lactating adenoma is huge and rapidly growing, it has to be differentiated from malignancy or the rare collision tumor containing both lactating adenoma and carcinoma [6,8,9]. History, cytological or histopathological examination are keys for definitive diagnosis [7,10].
According to several reports, lactating adenoma tends to be relatively small in diameter (around 3 cm in its greastest dimensions) and tends to self-regress [4,6,8]; and sometimes respond dramatically to antiprolactin therapy being rich in prolactin receptors [2], however, in this particular case the lactating adenoma did not regress spontaneously or even with anti-prolactin therapy and necessitated surgical excision. And we found that enucleating the mass with excision of part of the overlying stretched skin did not result in a bad esthetic outcome as the mass was completely encapsulated and compressing and pushing the surrounding breast parenchyma not infiltrating it (Fig. 5).
Microscopically, lactating adenoma resembles fibroadenoma or tubular adenoma, however it could be differentiated from fibroadenoma by the scanty stroma and from tubular adenoma by the lactational changes including intracytoplasmic or supranuclear vacuolisation and luminal secretions which is more pronounced during lactation rather than during pregnancy [2,5].
The rapid increase in size of a lactating adenoma was previously described to be the result of infarction within the lactating adenoma which often seen during early puerperium [11]. To our knowledge Reeves et al. 2000 reported the largest seen lactating adenoma having a clinical size of 25 cm × 18 cm followed by the report of Manipadam at al 2000 in whose the lactating adenoma was 20 cm × 14 cm clinically and 16 cm × 10 cm × 5 cm grossly [2,5]. The present case measured 27 cm × 18 cm clinically and 17 cm × 13 cm grossly and so it qualifies for the largest reported case of lactating adenoma. Beside being huge size, the present case of lactating adenoma was distinct in absence of infarction, the absent response to antiprolactin therapy and that the patient was not primigravidae.
Conclusion
This case of lactating adenoma that we have presented above was unique in its huge size and of being diagnosed in a multiparous lady. And we believe that the best treatment in such cases is enucleation after an attempt of antiprolactin therapy. We found enucleation of this huge lactating adenoma is quite easy with acceptable aesthetic outcome.
None.
None
“None of the authors has a financial interest in any of the products, devices, or drugs mentioned in this manuscript.”
Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.