Nodal Inclusions Research Articles

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.

Current concepts of ectopic nodal inclusions with special emphasis on nodal nevi.

Nodal inclusions of ectopic tissue within lymph nodes are seen comparatively often in dermatopathology and general pathology. Glandular and nonglandular epithelium, as well as melanocytic nevi can be observed within lymph nodes and represent mostly incidental findings without any relevance. The main challenge in reporting these morphologic features is to differentiate such benign inclusions from metastatic settlements of distinct organ tumors. As sentinel node biopsy and lymph node dissection have become standard procedure in clinical oncology and have an immense clinical impact, the correct evaluation of these nodal inclusions is indispensable to avoid undertreatment or overtreatment of patients. In addition, the genesis of these inclusions has not yet been satisfactorily clarified. Two concepts have been laid out: the theory of benign metastases and the migration arrest theory. However, neither theory has so far been able to answer the following questions: Why do we find more nodal nevi in patients with melanoma who had a sentinel node biopsy than in patients without melanoma, and why do we not find nodal nevi in deep visceral lymph nodes? We present a comprehensive review of the current knowledge on nodal inclusions, proposing a concept for the pathogenesis of nodal nevi, to answer these questions.

Benign Epithelial Inclusions in Axillary Lymph Nodes

The occurrence of various types of heterotopic epithelial structures in lymph nodes is a well-documented phenomenon. Here, we report on the presence of such inclusions in axillary lymph nodes. A total of 18 cases were identified. All patients were women, their ages ranging from 32 to 79 years (median, 57 y). Thirteen patients had concomitant or antecedent breast abnormalities, and 12 of them had undergone nodal sampling for staging purposes. The other 5 patients had noted enlarging axillary masses, with no clinical evidence of previous or concomitant breast or genital tract pathology. We classified the nodal inclusions on morphologic grounds into 3 main categories: those composed exclusively of glandular structures (glandular-type inclusions; 10 cases, 56%); those made up only of squamous cysts (squamous-type inclusions; 2 cases, 11%); and those containing both glandular and squamous epithelia (mixed glandular-squamous-type inclusions; 6 cases, 33%). We speculate about the possible mechanism for the migration of the epithelial cells into the lymph nodes, discuss the modifications that they may later undergo as a result of local and systemic factors, and consider the differential diagnosis with other conditions, particularly with metastatic well-differentiated breast carcinoma.

Neck masses secondary to heterotopic salivary gland tissue: a 25-year experience

Objectives The aim of this study is to review salivary tumors arising from heterotopic salivary inclusions in the periparotid and cervical lymph nodal tissues over a 25-year span. Methods A retrospective chart review revealed 24 patients with asymptomatic neck masses treated between 1976 and 2001, whose pathology demonstrated heterotopic salivary tissue or neoplasms arising from heterotopic salivary tissue. Results Nine cases were benign periparotid lymph nodes with heterotopic salivary inclusions, 3 of which had multimodal involvement. Fifteen cases of heterotopic salivary tumors were identified. The benign tumors were predominantly Warthin's tumor (8) with 1 pleomorphic adenoma. Malignant tumors included mucoepidermoid (3), acinic cell (2), and adenocarcinoma (1). Patients were treated by a superficial parotidectomy, neck dissection, or simple excision depending on site and preoperative workup. Adjuvant radiation therapy was included for high-grade malignancies. Among the 15 tumor patients, follow-up ranged from 1 month to 17 years. Nine patients are alive and disease-free, 5 are deceased, and 1 was lost to follow-up. Conclusions Heterotopic salivary tissue in periparotid and upper cervical nodes is a more common occurrence than historically recognized. Tumorigenic changes arise from heterotopic nodal inclusions, and although infrequent, should be considered in the differential diagnosis for isolated neck/periparotid masses and parotid Warthin's tumor. Suggested management, after a thorough clinical exam/needle aspiration biopsy, includes an imaging survey of the parotid gland and neck lymphatics with an appropriate resection to include a simple excision, parotidectomy, neck dissection, and/or irradiation as indicated. Isolated low-grade malignant lesions/benign lesions are adequately managed by excision or parotidectomy alone. High-grade malignant lesions require more extended surgery with possible irradiation.

Nodal inclusion cysts of the parotid gland and parapharyngeal space: A discussion of lymphoepithelial, aids‐related parotid, and branchial cysts, cystic warthin's tumors, and cysts in sjogren's syndrome

The purpose of this report is to examine the computed tomography scans, magnetic resonance images, and pathologic findings in 44 patients, 42 of whom had inclusion-type cysts of the parotid and parapharyngeal space of varying etiologies. Two additional cases of cystic changes in the benign lymphoepithelial lesion (BLEL) of Sjögren's syndrome are highlighted here, since they had unusually large cystic components mimicking acquired immunodeficiency syndrome-related parotid cysts (ARPCs). A retrospective examination identified 18 ARPCs, 3 lymphoepithelial cysts (LECs), 13 cystic Warthin's tumors, 8 branchial cysts, and 2 cases of cysts in patients with Sjögren's syndrome (BLEL), all of whom had imaging studies and pathologic confirmation. There were 30 men and 14 women with an age range of 25 to 72 years (median, 46.82 years). Any similarities in the imaging appearances were noted, as were any differences in pathologic detail. On imaging, only the cystic Warthin's tumors had any focal wall nodularity; the other cysts had smooth walls. When multiple parotid cysts were present, the distinguishing feature between ARPCs and cysts in BLEL (and some cystic Warthin's tumors) was the presence of diffuse cervical adenopathy in patients with ARPCs. Imaging usually could not differentiate between a solitary parotid LEC, a branchial cyst, and some cystic Warthin's tumors. Extraparotid lesions were either branchial cysts or cystic Warthin's tumors. Physicians should be aware of the variety of different inclusion-type cysts that may occur in the parotid gland and parapharyngeal space, all of which may have similar imaging appearances. Although imaging clearly identifies these cysts and may suggest a specific diagnosis, it must always be remembered that the precise diagnosis remains in the province of the pathologist.

Mesothelial cell inclusions within mediastinal lymph nodes

The presence of mesothelial cell inclusions within mediastinal lymph nodes is an extremely rare occurrence with apparently only two previously reported cases. We report a single case with immunohistochemistry and transmission electron microscopy. A study of 318 mediastinal nodes from 80 patients using haematoxylin and eosin and immunohistochemistry is reported with the observation of no further positive cases. A review of the literature concerning nodal inclusions found at other anatomical sites aids discussion on the aetiology of this type of nodal inclusion.

Benign lymph node inclusions mimicking metastatic carcinoma.

To draw attention to non-neoplastic inclusions in axillary lymph nodes removed from women with primary breast cancer which may be mistaken for metastases. Five examples of non-malignant inclusions were detected in axillary lymph nodes removed from women with mammary carcinoma. Immunohistochemical staining for CAM 5.2 and S100 markers, as well as morphological assessment were performed. Three of the five cases comprised naevus cells and two heterotopic epithelial elements. One of each was initially mistaken for metastatic carcinoma. Naevus cells in the capsule of axillary nodes are often arranged as lines of small, round cells and may readily be misinterpreted as metastatic lobular carcinoma. Heterotopic epithelial elements, in the form of tubules, can easily be mistaken for metastasis from an infiltrating ductal carcinoma. Awareness of the occasional occurrence of non-neoplastic nodal inclusions will help avoid misdiagnosis. If immunohistochemical markers for epithelial cells are used to screen lymph nodes for metastasis, such lesions could be detected more frequently. It is important to combine immunohistochemistry with morphological assessment and the use of a panel of antibodies in histological diagnosis.

Malignant lymphomas of the major salivary glands.

A follow-up of ten patients with lymphomas of the salivary glands indicated that tumors with a nodular pattern had an increased survival time. In 30% of the cases the lymphomas could be seen to arise from nodal inclusions within salivary parenchyma. No evidence for an immunologically deficient state or associated immune disease could be found.