Metastasis of Clear Cell Renal Cell Carcinoma to Uterine Leiomyoma: First Case Report and Review of Literature

Metastasis of clear cell renal cell carcinoma (clear cell RCC) to the gynecologic tract is infrequent, and involvement of the uterus is extremely rare. A review of the literature identified a total of 12 reported examples with metastasis to the uterine serosa (1), endometrium (5), cervix (5) and only one with metastasis to the myometrium. This report represents the first case of tumor-to-tumor metastasis involving a clear cell RCC with metastasis to a uterine leiomyoma. The patient was a 50-year-old woman status post-radical nephrectomy for newly diagnosed unilateral clear cell RCC (stage pT3a) with negative margins, who subsequently underwent a total abdominal hysterectomy and bilateral salpingo-oophorectomy for the incidental finding of multiple uterine masses measuring up to 14.5 cm suggestive of fibroid on pelvic ultrasound. The pathologic exam of the specimen was consistent with metastatic clear cell RCC (1.2 cm) to uterine leiomyoma, confirmed with keratin, vimentin, CD10, CA9, and PAX8 immunohistochemistry. The patient's postoperative course was uneventful, and no new lesions were identified at follow-up during the past 6 months.

Do mesothelin/MUC16 interactions facilitate adenocarcinoma metastases to intracranial meningiomas?

Background:

Meningiomas have been shown to express mesothelin, a high affinity binding site for MUC16, a transmembrane protein on adenocarcinoma cells. The mechanisms underlying adenocarcinoma metastases to meningiomas may provide insight into tumor-to-tumor metastases and adenocarcinoma metastases to leptomeningeal cells.

Methods:

Two meningiomas containing metastases from adenocarcinomas were identified and evaluated immunohistochemically for the expression and localization of mesothelin and MUC16.

Results:

Both meningiomas show extensive mesothelin immunoreactivity, and the adenocarcinomas metastatic to the meningiomas show mesothelin and MUC16 immunoreactivity at the interface with meningioma.

Conclusions:

Interactions between MUC16 and/or mesothelin on the cell membrane of adenocarcinoma cells with mesothelin on meningioma cells may facilitate adenocarcinoma metastases to meningiomas and possibly the leptomeninges.

Intracranial meningioma as initial clinical manifestation of occult lung carcinoma: case report

Intracranial meningioma with intratumor metastasis have been occasionally reported. However, to our knowledge, there are almost no reports of malignant tumors initially discovered due to metastasis to meningioma. A 74-year-old woman presented with amnesia. Magnetic resonance imaging showed a well-defined mass arising from falcotentorial junction and homogeneous enhancement. Histopathologic findings showed that the mass was a meningothelial meningioma, with the majority of the tumor cells propagating in sheets, however, a single area in the tumor tissue showed the different histology. Immunohistologically, cytokeratin 7 (CK7), thyroid transcription factor-1 (TTF-1), and Napsin were positive, which led to lung adenocarcinoma metastasis. Furthermore, E-cadherin staining showed a 70% positive rate in lung adenocarcinoma and 30% in meningothelial meningioma. We report our experiences regarding a case of lung cancer that metastasized to intracranial meningioma and its clinical presentation and pathology.

Intrameningioma metastasis of breast carcinoma

Tumor-to-tumor metastasis of breast carcinoma to meningioma is a rare phenomenon. It is likely underdiagnosed given the relatively high prevalence and comorbidity of these two primary tumor types, the lack of standardized methodologies for its diagnosis, and the tendency to obfuscate this lesion with simple meningioma or cerebral metastasis of breast carcinoma. Careful histopathologic study of the resected meningioma is the cornerstone of diagnosis of these lesions, although certain conventional radiological features along with specialized modalities may clue the diagnosis. Vigilance for this lesion is appropriate in selected patients with known breast cancer or meningioma, as the two are often coexistent in the same patient, permitting tumor-to-tumor metastasis. Detection of this rare disease process may alter the treatment plan and prognosis. Here, we report a case of breast carcinoma-to-meningioma metastasis in a patient who developed subacute neurological decline while undergoing long-term treatment of her primary, late-stage breast cancer.