Ductal carcinoma in situ arising in an epithelial inclusion within an axillary lymph node

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.

Misleading images of ductal carcinoma in situ: 4 lymph nodes with metastasis

Since sentinel lymph node examination became routine, findings of benign ectopic breast tissue in lymph nodes have increased. We report images of ductal carcinoma in situ (DCIS) in four lymph nodes in a 76-year-old woman with bilateral breast carcinoma. The right lumpectomy showed intermixed invasive lobular and ductal carcinoma, plus DCIS. 19 nodes were isolated in the axillary lymphadenectomy, 4 of which displayed solid and cribriform DCIS. Myosin and p63 immunohistochemical techniques were positive, suggesting an erroneous diagnosis of "metastatic DCIS". A further three cases of DCIS in lymph nodes have been previously reported, all with a distinct layer of myoepithelial cells with actin, myosin or p63. Biologically, these images of DCIS in lymph nodes are not credible and three major hypotheses have been proposed to explain these findings: Iatrogenic Mechanical Transport, Revertant DCIS, and primary DCIS of lymph nodes. We consider the first one the most plausible explanation. Our case is unique as several, rare findings are simultaneously observed. More new cases, together with additional immunohistochemical techniques and molecular testing on previous cases, are needed to find a definitive explanation of this histologic finding.

Heterotopic squamous epithelial inclusion cyst in a cervical lymph node in a child: a case report and literature review

BACKGROUND

A squamous epithelial inclusion cyst in a lymph node is a rare heterotopic phenomenon. Heterotopic squamous inclusion cysts in cervical lymph nodes are even rarer, and to date, only 3 such cases have been reported in the literature, none of which have described the ultrasound features. Here, we report a pediatric case, focusing on the ultrasonographic manifestations of the disease and the differential diagnosis of cervical space-occupying lesions in children.

CASE DESCRIPTION

We report the case of a 6-year-old boy in good health, who presented with a non-tender mass on the right side of the neck 1 month earlier. Some 7 days before admission, the mass gradually increased in size and became tender. Laboratory tests showed an increase in C-reactive protein of 17 mg/L (normal range: 0-8 mg/L). The physical examination revealed a palpable 3.0 cm × 2.0 cm mass with tenderness and poor mobility in the right submandibular region. Doppler ultrasonography showed an oval, ill-defined mass in the right submandibular area, consisting of a peripheral homogeneous hypoechoic component with hilar-like vascularity and an internal heterogeneous very hypoechoic component with patchy hyperechoic areas. The computed tomography (CT) scan showed a heterogeneously hypodense mass with irregular annular enhancement in the right submandibular region. Lymph node tuberculosis or space-occupying lesions were suspected based on the clinical and imaging findings. The mass was completely excised by surgery. The pathological diagnosis was a secondary infection of squamous epithelial inclusion cysts in the right cervical lymph node. The peripheral homogeneous hypoechoic component was normal lymph node tissue, and the internal heterogeneous very hypoechoic component was a squamous inclusion cyst with keratin debris. The patient was followed up for a total of 3 times after surgery, and no recurrence of the tumor was found.

CONCLUSIONS

Ultrasonography can help in the early diagnosis of heterotopic squamous inclusion cysts in children's cervical lymph nodes, and can be used to differentiate other cervical lesions. We reviewed the literature and found that this heterotopic phenomenon was more likely to occur in the submandibular region of the neck in younger patients. Surgery may be an effective treatment for this disease.

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

We report a case of an axillary lymph node containing benign glandular lesions, intraductal papilloma with florid and atypical duct hyperplasia, and ductal carcinoma in situ. We propose 2 theories for the development of the intraductal papilloma: from adjacent benign glandular inclusions, or from displaced epithelial cells from a previous intraductal papilloma in the ipsilateral breast. This case identifies yet another etiology for false-positive sentinel lymph nodes morphologically and by immunohistochemistry.