Malignant pleural mesothelioma metastatic to the submandibular salivary gland, simulating glandular hypertrophy, diagnosed by fine-needle aspiration biopsy: a case report and literature review

Lung cancer metastasizing to salivary glands: Systematic review

ABSTRACTS

Metastasis to salivary glands from the secondary source outside the head and neck region is extremely rare and Carcinoma Lung is one of the rarest sources of distant spread to salivary glands. Owing to missed diagnosis and misdiagnosis, accurate identification of clinical and pathological aspects of these metastatic lesions remains a challenging task. Many studies regarding metastasis to the oral cavity have been already documented in the literature, but very little research work has been done to analyse the cases of lung cancer metastasis as the sole primary source, particularly to salivary glands. Thus this review was conducted to analyse the published cases of lung cancer metastasizing to salivary glands as the only primary source till date. An electronic search of the published literature was performed without publication year limitation in PubMed/ Medline, Scopus, Google Scholar, Web of Science, Science direct, Embase, and Research gate databases, using Mesh keywords like (Lung cancer', OR 'Lung carcinoma), AND (Metastasis OR Metastases), And (Salivary glands OR Parotid gland OR Submandibular gland OR Sublingual gland). We also searched all related journals manually. The reference list of all articles was also checked. Our research revealed 34 relevant papers between 1965-2022 with a total of 44 patients. The most prevalent diagnosed metastatic Lung cancer was Small cell lung cancer. Parotid was the most common gland involved in metastasis. 48% of patients died of metastasis with a mean survival time of 2.2 years. Salivary gland metastasis from Lung cancer is very rare and has a poor prognosis. More cases need to be published in order to raise awareness of these lesions and gain a better understanding of their characteristics.

When the Diagnosis of Mesothelioma Challenges Textbooks and Guidelines

The diagnosis of malignant mesothelioma (MPM) does not pose difficulties when presenting with usual clinico-radiologic features and morphology. Pathology textbooks and national/international guidelines generally describe the findings of classic MPM, underlining common clinical presentation, the gold standard of sampling techniques, usual morphologic variants, immunohistochemical results of several positive and negative primary antibodies in the differential diagnosis, and the role of novel molecular markers. Nevertheless, MPM often does not follow the golden rules in routine practice, while the literature generally does not sufficiently emphasize unusual features of its manifestation. This gap may potentially create problems for patients in sustaining a difficult diagnosis of MPM in clinical practice and during legal disputes. Indeed, the guidelines accidentally tend to favor the job of lawyers and pathologists defending asbestos-producing industries against patients suffering from MPM characterized by uncommon features. The current review is aimed at underlining the wide spectrum of clinical and radiological presentation of MPM, the possibility to consistently use cytology for diagnostic intent, the aberrant immunohistochemical expression using so-called specific negative and positive primary antibodies, and finally proposing some alternative and more unbiased approaches to the diagnosis of MPM.

Mesothelium and Malignant Mesothelioma

The mesothelium is an epithelial structure derived from the embryonic mesoderm. It plays an important role in the development of a number of different organs, including the heart, lungs, and intestines. In this publication, we discuss aspects of the development of the mesothelium, where mesothelial structures can be found, and review molecular and cellular characteristics associated with the mesothelium. Furthermore, we discuss the involvement of the mesothelium in a number of disease conditions, in particular in the pathogenesis of mesotheliomas with an emphasis on malignant pleural mesothelioma (MPM)—a primary cancer developing in the pleural cavity.

Fine needle aspiration biopsy of metastatic malignant mesothelioma with myxoid change and signet ring cells: A case report and review of the literature

Malignant mesothelioma (MM) is a rare neoplasm, which is most commonly encountered in cytology through effusion specimens. Fine needle aspiration biopsy of MM, particularly the epithelioid subtype, can be a source of diagnostic difficulty and may mimic sampling of an adenocarcinoma. This is the first case report to demonstrate abundant extracellular myxoid material and numerous intracellular vacuoles, including signet ring cells, in a fine needle aspirate of metastatic MM. A review of the literature for myxoid change and vacuoles in fine needle aspiration biopsies of MM discloses that vacuoles are found in up to 35% of aspirates of MM, but myxoid change is very rare, reported in <5% of the cases. Cytologists should be aware of this rare morphologic pattern of metastatic epithelioid MM.