Mimicry of Minute Pulmonary Meningothelial-like Nodules to Metastatic Deposits in a Patient with Infiltrating Lobular Carcinoma: A Case Report and Review of the Literature.

Minute pulmonary meningothelial-like nodules (MPMNs) are incidentally found lesions in lung resection specimens and autopsies. MPMNs have been associated with neoplastic and non-neoplastic pulmonary conditions and occasionally with extrapulmonary diseases. We report a case of a female patient presenting with invasive lobular carcinoma of the breast and MPMNs, masquerading as metastatic deposits. We describe the morphological, immunohistochemical and ultrastructural features of MPMNs and emphasize the importance of their recognition for proper staging and treatment of patients. To our knowledge, this is the first case in the English literature describing this coexistence.