Breast Hamartoma in the Male Sex: Case Report

Breast tissue is identical in males and females until puberty, when the male breast remains rudimentary, while in females it begins rapid development, differentiating under hormonal influence [1]. Mainly estrogens, but also progestogens, prolactin, corticosteroids and growth hormone stimulate the proliferation of glandular tissue, while androgens counteract this effect. In delayed puberty, involution and atrophy of ducts and stroma occurs. As a result of this process, an adult man’s breast is made up of adipose tissue, subareolar atrophic ducts, and fibrous tissue. Cooper’s ligaments, present in the female breast, are absent in men [2].

Hamartomas were initially defined as mastomas in 1928 by Prym. Afterward, several cases were reported and classified as lipofibroadenomas, fibroadenolipomas, or adenolipomas, as a based on the predominant component of the breast tissue. Arrigoni et al. first used the term hamartoma in 1971. Hamartoma is referred to as myoid hamartoma, a rarer form, when it shows a significant smooth muscle component; this term was first used by Davis and Riddell in 1973.

Hamartoma of the breast is an uncommon benign tumor of glandular tissue, composed of glandular, adipose, and fibrous tissue. The frequency of the tumor is reported between 0.04 and 1.15% and it accounts for 4.8% of all benign breast tumors. In men, it is represents <1% of all breast lesions. The risk factors have not been clearly identified; however, there are some factors that have been related to a higher risk such as:

• (1)

  Age: higher frequency in middle-aged and older men.

• (2)

  Elevated estrogen levels.

• (3)

  Family history of breast cancer [3].

Common symptoms include tumor in the breast, which is usually hard, mobile and painless on the breast tissue, tenderness or pain in the breast, changes in the shape of the breast, and rarely there may be nipple discharge. They can be worrying due to their similarity to malignant tumors.

The pathogenesis is still poorly understood and mammary hamartoma is not a well-known disorder, but they are though to result from dysgenesis rather than a true tumorous process. So its diagnosis is underestimated by clinicians because of the varied clinical presentation, and pathologists, as a microscopic appearance is not distinctive. However, identification of hamartoma is important because they are the problems of recurrence, coexistent carcinomas and association with Cowden syndrome.

With increasing social awareness and the use of numerous diagnostic procedures on breast lumps, including mammography, ultrasound, and MRI, it is expected that more hamartomas will be reported. Breast hamartomas have a typical mammographic appearance. The radiolucent lesions include fat, various amounts of fibrous and adenomatous tissues, with smooth rims, and occasionally, a thin capsule. We evaluate breast hamartomas as having sonolucent fat and a heterogeneous internal echo pattern with echogenic fibrous components.

An excision and histological examination are necessary for the differential diagnosis and also for any epithelial lesions of hamartoma. In most cases, they are treated with surgical removal (excision is enough treatment if there is not coincidental epithelial malignant lesion), and long-term results are usually good, with no recurrence of the lesion [4].

Ductal hyperplasia, apocrine metaplasia, calcification, and adenosis may occur within the hamartoma, with rarer instances of lobular or ductal intraepithelial neoplasms. Although hamartoma is usually benign, a malignant transformation is possible.

A 53-year-old male with no significant medical history comes for evaluation because he has a right breast nodule.

Physical examination: 2 cm periareolar tumor, hard, in the right breast.

USG: BIRADS 4B

Mammogram: unilateral right mammogram in cranio-caudal and oblique-lateral projections. Skin and nipple-areola complex retain normal size and density. At the retroaerolar level, a heterogeneous increase in density is observed, and complement with breast ultrasound is suggested in search of nodular lesions. Axillary hollow without alterations. BIRADS 3 (Fig. 1).

Trucut biopsy: gynecomastia with nodular pattern and chronic nonspecific inflammation.

Surgical procedure: an outpatient simple right mastectomy was performed, where a 2 × 2 cm fibrous retroaereolar tumor was found, and a drenovac type drainage was placed (Fig. 2).

Histopathological study: a breast nodule consisting of mixture of ductolobulillary structures with involutional changes alternating with mature adipose tissue and bands of fibrous tissue, ductal ectasia with fibrosis, and periductal lymphoplasmacytic infiltrate. With a final diagnosis of breast hamartoma, tumor size of 2 × 2 × 1.5 cm with edges and surgical bed free of lesion, periductal mastitis (Fig. 3). Follow-up continued through outpatient consultation, drainage was removed 1 month after surgery, with adequate clinical evolution, and hospital discharge 2 months after surgery (Fig. 4).

Hamartomas are more common in pregnant and lactating women, indicating that hormones and endocrine factors may play a role in the development of these tumors. In men, there is need to specifically differentiate a breast hamartoma from male breast development [5].

Breast hamartoma in men is very rare, and the underlying pathology and biology have not yet been clearly defined. In addition, as men typically pay less attention to palpable masses within breast tissue, it is commonly observed that lesions can grow substantially before seeking medical attention. As such, hamartoma in men tends to be detected later than in women, which requires differentiation from a malignant lesion.

Breast hamartomas typically appear in women around 45 years of age; it is very uncommon it is presented in man; however, our patient is a man of 53 years old. Diagnosis is usually difficult because the symptoms are nonspecific, and in men, less attention is paid to breast tumors because they are less common, preventive medicine is not performed on this issue for them. In our case, this was detected by self-examination of palpable tumor in a right breast, for which he went to medical evaluation, where a mammogram was request with a result of BIRADS 3, with a heterogeneous increase in density retroareolar for which ultrasound was performed with report of BIRADS 4B. Biopsy is taken by trucut reporting gynecomastia with nodular pattern and chronic nonspecific inflammation. Based on the results, surgical treatment is offered and accepted, an outpatient simple right mastectomy was performed, where a 2 × 2 cm fibrous retroareolar tumor was found. And it is not until the final histopathology result that a breast hamartoma is confirmed, achieving sufficient treatment, and reducing the possibility of recurrence or malignant transformation, which although it occurs with a low incidence can occur in some patients [6].

Breast hamartoma is a rare, benign, slow-growing breast tumor, accounting for 0.12–0.24% of all breast tumor. Men with diagnosed breast hamartomas are mostly 35 years old and rarely younger than 18 years old, with an average age of 45 years; however, in our case the average age was exceeded [7].

Clinically, a hamartoma presents as a well-defined, encapsulated, painless mass, its sizes range from 1 to 8 cm. The most common radiological feature is a well-defined, compressible oval mass that is composed predominantly hyperechoic fat [8].

Diagnosis is made by combining the results of clinical, radiological, and histopathological examination [9].

Surgical treatment is recommended in patients with suspected hamartoma; this allows the examination of the components of the tissue and leads to histopathological confirmation [10].

We thank our General Hospital “Dr. Norberto Treviño Zapata” and our families for their support.

Ethical approval is not required for this study in accordance with local and national guidelines. Written informed consent was obtained from the patient for publication or this case report and any accompanying images.

The authors have no conflicts of interest to declare.

This study was not supported by any sponsor or funder.

Ana Aracely Enciso Hurtado, Carlos Orlando Pacheco González, Alexandra Nohemí Morado López, Michelle Georgina Macías Rodríguez, Mauricio Muñoz Muñoz: conceptualization, data curation, formal analysis, investigation, writing – original draft, and writing – review and editing. The CARE Checklist has been completed by the authors for this case report, attached as online supplementary material at https://doi.org/10.1159/000543389.

All data generated or analyzed during this study are included in this article. Further inquiries can be directed to the corresponding author.