Fine-needle aspiration biopsy and intraoperative cytologic smear findings in a case of benign mesothelial-cell inclusions involving a lymph node: case report and review of the literature

Embolised mesothelial cells in a tracheobronchial lymph node associated with idiopathic chylopericardium in a dog

A 5·5-year-old male castrated Bernese mountain dog presented with respiratory difficulties and was diagnosed with haemorrhagic pericardial effusion which transformed into chylopericardium. Thoracic duct ligation and subtotal pericardiectomy in combination with biopsy of an enlarged tracheobronchial lymph node were performed. Multiple clusters of mesothelial cell emboli were observed in the subcapsular sinus of the lymph node. No causative agent for the pericardial effusion could be identified, suggesting that this is a case of mesothelial cell embolisation associated with idiopathic -chylopericardium in a dog.

A Rapidly Enlarging Squamous Inclusion Cyst in an Axillary Lymph Node following Core Needle Biopsy

A 73-year-old woman was found to have a 1.7 cm axillary mass, for which a core needle biopsy was performed. The specimen revealed fragmented squamous epithelium surrounded by lymphoid tissue consistent with a squamous inclusion cyst in a lymph node, but a metastatic squamous cell carcinoma could not be excluded. Within one month, the lesion enlarged to 5 cm and was excised. Touch preparation cytology during intraoperative consultation displayed numerous single and sheets of atypical epithelioid cells with enlarged nuclei and occasional mitoses, suggesting a carcinoma. However, multinucleated giant cells and neutrophils in the background indicated reactive changes. We interpreted the touch preparation as atypical and recommended conservative surgical management. Permanent sections revealed a ruptured squamous inclusion cyst in a lymph node with extensive reactive changes. Retrospectively, the atypical epithelioid cells on touch preparation corresponded to reactive histiocytes. This is the first case report of a rapidly enlarging ruptured squamous inclusion cyst in an axillary lymph node following core needle biopsy. Our case demonstrates the diagnostic challenges related to a ruptured squamous inclusion cyst and serves to inform the readers to consider this lesion in the differential diagnosis for similar situations.

Endobronchial ultrasound-guided transbronchial needle aspiration cytology: a state of the art review

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a recently developed, accurate, safe and cost-effective technique that allows sampling of mediastinal lymph nodes and peribronchial lesions including pulmonary and mediastinal lesions. Its major indications are the nodal staging of non-small cell carcinomas of the lung, their restaging after chemotherapy and/or radiation, the diagnosis of sarcoidosis and of metastases from extrathoracic malignancies, and the diagnosis of mediastinal lymphadenopathy and masses of unknown aetiology. From our experience at the University of Minnesota and a comprehensive review of the literature, we discuss technical aspects of the procedure, its advantages and limitations in comparison with other methods of sampling mediastinal lymph nodes, focusing on the role of the cytopathologist in ensuring the effectiveness of the procedure. An algorithmic approach to the cytological diagnosis, starting with the determination of the adequacy of the sample, is also presented.

Mesothelial pelvic lymph node inclusion in a patient with ovarian microinvasive borderline mucinous tumor: case report with review of the literature

The presence of mesothelial cell inclusions in lymph nodes is rare. Localization of these inclusions in abdominal and pelvic lymph nodes is an exceedingly rare event, with only eight cases reported. We report here a case of mesothelial cell inclusions in pelvic lymph node of a patient with ovarian microinvasive borderline mucinous tumor. This case differs from the previously reported cases for the following reasons. First, there was no evidence of serosal effusion. Second, it is the first reported case of nodal mesothelial inclusions in a patient with ovarian microinvasive mucinous borderline tumor. Last, histologically, mesothelial cell inclusions were accompanied by psammoma bodies. The potential problem of misdiagnosis as a metastatic tumor can be avoided by an awareness of these inclusions, supported by immunohistochemical results.

Benign pulmonary epithelial inclusions within the pleura: a case report

Background

The normal visceral and parietal pleura are composed of a mesothelium-lined layer of fibrous connective tissue, consisting predominantly of collagen and elastin fibers, with interspersed nerves, lymphatics, and blood vessels. There is no normal epithelial component to the pleura, and the histologic finding of epithelial cells within pleural tissue typically indicates the presence of a malignant process. The one documented exception to this rule is the occasional occurrence of endometriotic implants, which can result in cyclic thoracic symptomatology and occasionally even hemothorax.

Case Presentation

We present a case of seemingly benign epithelial inclusions within the pleura of a sixty year-old male patient who underwent exploratory thoracotomy and subsequent resection of bullous emphysematous blebs. Examination of the surgical specimen revealed well-defined nests of benign-appearing epithelial cells in glandular configurations at multiple sites within the pleura. These cells were immunopositive for TTF-1 and CK7 and immunonegative for calretenin, CK20, and CEA, indicating pulmonary epithelial derivation. Six months after resection, the patient is in stable health, with no clinical or radiologic evidence of bronchogenic carcinoma.

Conclusion

To our knowledge, this is the first report of benign pulmonary epithelial inclusions within pleural tissue. It is important to be aware that benign pleural inclusions occur, so as to avoid confusion with more serious processes in a population of patients who may have oncologic risk factors.

Ectopic mesothelial cell proliferation in cervical lymph nodes after severe ovarian hyperstimulation syndrome

OBJECTIVE

To report a case of ectopic mesothelial proliferation in cervical lymph nodes after severe ovarian hyperstimulation syndrome.

DESIGN

Case report.

SETTING

University-affiliated teaching hospital.

PATIENT(S)

A 42-year-old woman underwent a successful IVF attempt and developed severe ovarian hyperstimulation syndrome and pathologically enlarged cervical lymph nodes.

INTERVENTION(S)

Paracentesis, cervical lymph node biopsy followed by cytology, histology, and immunohistochemistry.

MAIN OUTCOME MEASURE(S)

Resolution of symptoms, pregnancy outcome, correct pathological diagnosis.

RESULT(S)

Paracentesis resulted in resolution of symptoms of ovarian hyperstimulation. The diagnosis of ectopic mesothelial proliferation in cervical lymph nodes was made after immunohistochemical examination of cervical lymph nodes. The pregnancy progressed normally, and at 40 weeks the patient spontaneously delivered a healthy son weighing 3,060 g.

CONCLUSION(S)

This case describes ectopic mesothelial cell proliferation localized in and around cervical lymph nodes occurring at 9 weeks' gestation in a patient who earlier developed severe ovarian hyperstimulation syndrome 10 days after ET. Ectopic mesothelial cell proliferation in lymph nodes is an extremely rare event, and this is the first case described after ovarian hyperstimulation. Familiarity with this event is important for the clinician as well as for the pathologist in preventing the misdiagnosis of malignancy.