Oral metastatic clear-cell tumours

Abstract

We report two extremely rare cases of metastatic clear-cell carcinomas, which metastasized from and to the oral cavity and both presented clinically in the oral cavity. First case was a primary lesion in the oral cavity, which showed distant metastatic deposits in liver, kidney, bone and brain. Histopathologically, lobules of pleomorphic clear cells were evident descending from the overlying mucosa, raising the suspicion of renal cell carcinoma. Immunohistochemical staining for CD10 was negative and the case was diagnosed as clear-cell type of oral squamous cell carcinoma which had disseminated to distant organs. In the second case, dysplastic clear granular cells were seen invading the bone. Immunohistochemical staining for CD10 showed focal mild positivity, confirming the diagnosis as clear-cell renal carcinoma which had metastasized to the oral cavity. Metastatic tumours must be considered in the differential diagnosis of rapidly growing ulcero proliferative lesions in the oral cavity.

Metastatic Sarcomatoid Renal Cell Carcinoma: A Journey From the Kidney to the Gingiva

“…The clear cell morphology and arrangement were found to be altered with the loss of normal organoid architecture and showed extensive dedifferentiation towards mesenchymal changes, which is very uncommon and inconsistent with conventional clear cell RCCs seen in the literature [ 1 ]. The existence of these clear cells could be confused with the clear cell variant of mucoepidermoid carcinoma, which was ruled out by periodic acid-Schiff (PAS) staining showing negativity for clear cells [ 10 ]. A few cells showed elongated nuclei with typical “cigar-shaped” nuclei, and the differential diagnosis of leiomyosarcoma was considered, but immunohistochemistry found S-100 to be negative.…”