Intraductal carcinoma arising in intraductal papilloma in an axillary lymph node: review of the literature and proposed theories of evolution

Ductal Carcinoma Arising in a Squamous Epithelial Inclusion Cyst within an Axillary Lymph Node: A Challenging Nodal Metastasis

Introduction. Assessment of axillary lymph nodes in breast carcinoma is an important part of staging to guide appropriate clinical management. Lymph node inclusions of different types, including nevoid, squamous, and glandular, are rare but have been reported in multiple different anatomic locations including the axilla. These can result in diagnostic challenges and pose risks of misdiagnoses. Rarely, malignancies may arise intrinsic to otherwise incidental benign nodal inclusions. Case Presentation. We report a case of ductal carcinoma diagnosed within a squamous epithelial inclusion cyst within an axillary lymph node in a patient with pure ductal carcinoma in situ (DCIS) of the ipsilateral right breast. To our knowledge, this is the fifth report in the literature of breast carcinoma confirmed within an axillary inclusion in a patient with pure DCIS. Evaluation of the primary DCIS and lymph node inclusions, by routine and immunohistochemical stains, was performed for assessment. Discussion. The presence of lymph node inclusions can pose a challenge in assessment of benignity and malignancy, on frozen and permanent histologic sections. Pathologists should carefully evaluate lymph node inclusions to ensure that intrinsic malignancies are not missed within rare otherwise benign appearing incidental epithelial rests.

Intraductal papilloma arising in ectopic breast tissue within the axillary region

Intraductal papilloma arising within breast tissue is relatively a common pathology. However, it is rare to find a papilloma within ectopic breast tissue. To our understanding there have been only a few reports of this. Here, we present a rare case of extranodal Intraductal papilloma within axillary ectopic breast tissue.

Endocervicosis in an Intramammary Lymph Node

Benign müllerian inclusions are frequently encountered within infra-diaphragmatic locations such as pelvic lymph nodes, bladder, cervix and vagina. Supra-diaphragmatic müllerian inclusions, especially endocervicosis, are exceedingly rare. We report a case of endocervicosis within an intramammary lymph node in a 49-year-old woman. To the best of our knowledge, this is the second reported case.

Ductal Carcinoma In Situ Simultaneously Involving the Breast and Epithelial Inclusions in an Ipsilateral Axillary Lymph Node

Benign cystic epithelial inclusions with squamous, glandular, or Müllerian phenotypes are known to occur in the axillary lymph nodes of patients with benign and malignant breast disease. Careful evaluation of hematoxylin and eosin-stained slides and correlation with the histologic findings in the ipsilateral breast are paramount in evaluation of suspected benign inclusions. In this case of ductal carcinoma in situ (DCIS) of the breast in a 73-year-old woman, DCIS also involved epithelial inclusions in an ipsilateral axillary lymph node. The recognition of these benign epithelial elements, and awareness that they can be involved by DCIS, is crucial to avoid the overdiagnosis of metastatic carcinoma.

Intraductal papilloma in an axillary lymph node of a patient with human immunodeficiency virus: a case report and review of the literature

Introduction

Inclusions of ectopic breast tissue in axillary lymph nodes are reported very infrequently and typically are only identified microscopically as an incidental finding. Furthermore the development of a benign proliferative lesion in the form of an intraductal papilloma from intranodal ectopic breast tissue is an extremely rare phenomenon with only three previous cases reported. This report describes an unusual and rare case of an intraductal papilloma arising in an axillary lymph node of a patient known to have the human immunodeficiency virus.

Case presentation

A 40-year-old Black African woman underwent excision of an enlarged palpable axillary lymph node. In the preceding 7 years she had received at least six separate surgical excisions to her ipsilateral breast for papillomatosis. The last surgical intervention was performed 1 year prior to presentation with an enlarged axillary lymph node. Histological examination of her axillary lymph node revealed a papillomatous proliferative epithelial lesion within an apparent encompassing duct, resembling a mammary intraductal papilloma. In the surrounding lymphoid tissue small groups of duct-like structures were additionally noted. Immunostaining with a panel of myoepithelial markers in conjunction with oestrogen receptor produced a mixed heterogeneous staining pattern in both the papillomatous lesion and the peripheral duct-like structures. This confirmed the diagnosis of a benign intraductal papilloma within an axillary lymph node, considered to have arisen from ectopic breast tissue.

Conclusions

This case demonstrates that intranodal ectopic breast tissue has the potential to undergo benign proliferative change albeit extremely rarely. Therefore this possibility must be considered to ensure the correct diagnosis is made. In addition, to the best of our knowledge, this is the first case report which has described recurrent intraductal papillomas and the subsequent development of an intraductal papilloma within an ipsilateral axillary lymph node, in a patient who is human immunodeficiency virus positive. There is minimal literature investigating the specific types of breast pathologies experienced by patients infected with human immunodeficiency virus and it remains unexplored as to whether human immunodeficiency virus may lead to proliferative papillomatous epithelial changes. This report considers the role of the human papillomavirus and recommends that further investigatory studies are required.

Clear cell nodular hidradenoma involving the lymphatic system: a tumor of uncertain malignant potential or a novel example of "metastasizing" benign tumor?

Exceedingly rare cases of neoplasms with clear-cut histopathologic features of benignity can show locoregional or even distant spread. Such cases can become putative examples of "benign metastasis" when a completely favorable clinical outcome is documented after an adequately long follow-up. We report 8 cases of morphologically benign clear cell nodular hidradenoma (CCNH) with lymphatic involvement. In 5 cases the cutaneous tumor showed small foci of intravascular deposits of neoplastic cells; in 2 cases the cutaneous tumor presented with a synchronous tumor in a regional node; in 1 case a nodal location CCNH was found with no evidence of any primary in the skin. All the cases were treated with conservative surgery and none of them showed disease progression during a follow-up period ranging from 2 to 11 years. These data suggest that in the absence of other histopathologic features of malignancy, lymphatic spread in CCNH can still carry an excellent prognosis and can be therefore considered as an example of "benign metastasis." As the latter concept can be set forth only after an uneventful long-term follow-up, in routine practice, cases of morphologically benign CCNH with lymphatic involvement are best labeled "atypical CCNH," or "CCNH-like tumor of uncertain malignant potential."

Synchronous ductal carcinoma in situ of the breast and within epithelial inclusions in an ipsilateral sentinel lymph node

Epithelial inclusions in the axillary lymph nodes are very rare and have even less commonly been reported with either benign or malignant changes. We present a case of synchronous high-grade micropapillary ductal carcinoma in situ arising in the breast and in an epithelial inclusion in an ipsilateral sentinel lymph node. Despite extensive sampling, no focus of invasive carcinoma was identified. This unique case highlights the difficulty in diagnosis of metastatic disease when there is a malignant change in an epithelial inclusion in a sentinel lymph node and highlights the need for very careful histologic assessment of such lesions.