Pericardial effusion as primary manifestation of metastatic cutaneous adenoid cystic carcinoma: diagnostic cytopathology from an exfoliative sample.

Adenoid cystic carcinoma (ACC) occurs not only as a tumor of salivary glands, but also in very unusual locations, such as in the skin. Only very few cases of primary cutaneous of ACC have metastasized to the lymph nodes and lungs. We present a 53-year-old man with metastasis of the pericardium from a primary cutaneous ACC (PCACC) of the scalp, which had been surgically treated 14 years ago. Exfoliative cytologic findings from pericardial effusion included small clusters of basaloid cells with occasional cystlike spaces containing mucoid material. To our knowledge, this is the first case of pericardial metastasis from a PCACC.

Primary clear cell meningioma of the orbit mimicking a metastatic carcinoma: usefulness of immunohistochemistry and cytogenetic analysis.

Clear cell meningiomas (CCM) are rare tumors of the nervous system that usually occur in young patients and display high recurrence rates and potentially aggressive behavior. In this report, we describe a primary CCM of the orbit in an 84-year-old man with a previous history of a clear cell carcinoma of the kidney. Histologically, the tumor demonstrated a sheet-like proliferation of clear polygonal cells. Differential diagnosis includes metastasis of clear cell carcinomas. Immunohistochemistry, by showing that tumor cells expressed vimentin, epithelial membrane antigen, and progesterone antigens, and cytogenetic analysis, by identifying a monosomy 22, confirmed the diagnosis of CCM.

Dedifferentiated liposarcoma of the pleura mimicking a malignant solitary fibrous tumor and associated with dedifferentiated liposarcoma of the mediastinum: usefulness of cytogenetic and molecular genetic analyses.

Dedifferentiated liposarcoma of the pleura is an extremely rare malignancy mimicking a variety of tumors, such as other sarcomas, mesothelioma, and malignant solitary fibrous tumor of the pleura. Liposarcoma of the pleura can be combined with mediastinal involvement, and in most cases it may be impossible to be certain where the primary tumor originated. In this report, we describe a very rare occurence of a dedifferentiated liposarcoma of the pleura in a 76-year-old woman associated with a distinct second dedifferentiated liposarcoma of the mediastinum. Histologically, the pleural tumor demonstrated spindle cells arranged in a fascicular pattern, whereas the mediastinal tumor was mostly adipocytic with small areas of spindle cells. Vimentin and protein S100 were focally expressed by the tumor cells. The differential diagnosis of the pleural mass included malignant solitary fibrous tumor. Cytogenetic analysis showed supernumerary ring chromosomes in the pleural tumor, as well as strong amplification of MDM2 and CDK4 genes in both tumors. Array comparative genomic hybridization showed amplifications of chromosome arms 6q, 12q, and 15q, shared by both tumors and strongly pointing to a common origin.