Unusual tumors of the breast

Encapsulated Papillary Carcinoma: A Case Report and Review of the Literature

Papillary neoplasms are a distinct assemblage of breast lesions whose main characteristic is the presence of fibrovascular cores which are surrounded by epithelial cells. Papillary lesions are of heterogenous nature, with similar clinical behavior and histomorphologic characteristics. Their biological patterns, however, can be quite different. According to the World Health Organization (WHO) (2019), breast tumors have been recently classified into five subdivisions of papillary neoplasms. They are namely: intraductal papilloma, papillary ductal carcinoma in situ, encapsulated papillary carcinoma (EPC), solid-papillary carcinoma and invasive papillary carcinoma. Despite the papillary architecture being easily recognized, histological variations are diagnostically challenging. The presence or absence of myoepithelial cells in the papillary cores can distinguish the malignant from the benign lesions respectively. EPC is a rare, histologically unique carcinoma type whose main characteristic is a thick fibrous capsule at the periphery and a prolific cell structure with fibrovascular stalk support. A characteristic feature is the absence of myoepithelial cells at the surrounding thick fibrous capsule. Usually, EPC maintains a slowly developing tumor despite the absence of myoepithelial cells. An EPC case presents diagnostic difficulties since it bears close resemblance to malignant and benign papillary breast lesions. Upon a clinical and radiological evaluation, EPC commonly appears as a benign lump. In mammography, the tumor is frequently found in a retroareolar position as a well-defined mass. On the other hand, in an ultrasound, the tumor will appear as a cystic lesion characterized by solid components. The clinical picture of EPC is usually an asymptomatic benign mass which at times can be felt through auto-palpation or screening mammography. A bloody nipple discharge is regarded as a common symptom. We report a case of an EPC of a 81-year-old woman who presented with a mass in the left breast.

Diagnosis, treatment, and outcomes of encapsulated papillary carcinoma: a single institution experience

Background.

Encapsulated papillary carcinoma (EPC) is a rare entity of breast cancer accounting for approximately 1–2% of all breast tumours. There are no evidence-based guidelines for the treatment of EPC.

Materials and methods.

From the database of the National Centre of Pathology (NCP), we obtained pathology reports of 19 patients with histologically confirmed EPC, who were treated at the National Cancer Institute (NCI) in Vilnius, Lithuania, between July 2009 and July 2015. Demographic, diagnostic and treatment data were collected from medical records retrospectively.

Results.

During the indicated period, 19 patients with EPC were treated at the NCI. Three of them had pure EPC, they were 74 to 81 years of age at the time of diagnosis (mean 76.7 years, median 75 years); all of them are still alive and no disease progression has been observed. Seven patients had EPC associated with carcinoma in situ. Nine patients had EPC associated with invasive breast ductal carcinoma. All patients underwent surgery, in most cases – wide local excision. Only one patient died.

Conclusions.

EPC is a rare form of breast cancer and usually presents with an invasive breast carcinoma or carcinoma in situ in postmenopausal women. Tumours have an excellent prognosis in the cases of pure EPC and in both EPC associated with carcinoma in situ (CIS) and invasive carcinoma.

Basal cell adenoma of the breast

Salivary gland-like neoplasms of the breast are a known entity. A single novel case of basal cell adenoma of the breast is presented, and the presentation, treatment, and morphologic features of this case are discussed.

Basal cell adenocarcinoma arising in salivary gland metaplasia of the breast: a novel salivary gland-type tumor developing in the breast

A variety of salivary gland-type lesions occur in the breast. Three cases of a novel mammary carcinoma arising in a background of salivary gland metaplasia and morphologically similar to basal cell adenocarcinoma of the salivary gland are presented. The clinical presentation, morphologic features, treatment, and follow-up of these cases are discussed.

Intracystic papillary carcinoma of the breast: report of three cases and literature review

Intracystic papillary carcinoma is a rare malignant tumor of the breast. It occurs communally in postmenopausal women. Clinically it can be asymptomatic or manifested by a breast mass or a nipple discharge. On imaging intracystic papillary carcinoma has usually benign features. Pathologic diagnosis can be difficult at classical histological examination and identification of myoepithelial cells layer by immunohistochemical study can be useful. In the majority of cases of pure intracystic papillary carcinoma, conservative management is possible. Adjuvant therapy is still controversial and prognosis is excellent. We report three cases of intracystic papillary carcinoma diagnosed on immunohistochemical examination and managed with conservative surgery.

Adenomyoepithelial tumors of the breast: imaging findings with histopathologic correlation

OBJECTIVE

The purpose of this essay is to describe the imaging characteristics of adenomyoepithelial tumors of the breast.

CONCLUSION

Adenomyoepithelial tumors of the breast are rare, and most are benign. The predominant mammographic and ultrasound feature is an irregular mass with suspicious imaging findings. This uncommon condition should be included in the differential diagnosis of noncalcified masses found on mammograms and of solid masses with associated hypervascularity on ultrasound images. Biopsy is necessary for histologic evaluation, and the management is surgical excision.