A Case of Renal Metastasis from Follicular Thyroid Carcinoma Mimicking Renal Cell Carcinoma / 대한이비인후과학회지

Follicular thyroid carcinoma is the second most common form of thyroid cancer. It accounts for 10 percent of all thyroid cancer, and is found three times more frequently in men than in woman. It is well known that follicular thyroid carcinoma usually occurs in regions where it is hard for people to intake iodine. Most follicular thyroid carcinomas occur asymptomatically but occasionally reveal as masses in the thyroid nodules. The occurence of metastasis of follicular thyroid cancer in the lymph node is less than 10%, which is relatively low compared to that of papillary cancer. Follicular carcinomas are metastasized hematogenously and are common in the bone, liver, lung and brain. It is especially rare for metastatic follicular thyroid cancer to be diagnosed as renal tumor. We recently experienced and further investigated a case of follicular thyroid carcinoma that metastasised to the kidney in a 57-year-old woman, who had had abdominal distension. We report this case with a review of the reference.

Metastatic thyroid carcinoma in the kidney

Thyroid carcinoma, particularly papillary thyroid carcinoma, may present with a wide range of clinical course--from an indolent to an aggressive form of poorly differentiated thyroid carcinoma. About 10% of patients with papillary thyroid cancer develop distant metastasis to the lymph nodes, lungs, mediastinum, or bone. Several cases of unusual metastasis to the kidney have been reported previously. A rare case of renal metastasis from papillary thyroid carcinoma and the roles of PET and SPECT-CT in its detection are presented here.

Sigmoid Colon Cancer with Isolated Metastasis to the Left Kidney

We report the case of a 63-year-old female with sigmoid colon cancer and isolated metastasis to the left kidney at the time of initial diagnosis. An anterior resection of the sigmoid colon and a left nephrectomy were performed. Three cycles of adjuvant chemotherapy consisting of oxaliplatin, 5-fluorouracil, and leucovorin were given, but two months after the surgery, multiple metastases of the liver were detected on a CT scan. The patient refused further treatment and died 5 months after the discovery of an isolated metastasis. An isolated metastasis to the kidney is very rare in clinical practice. A nephrectomy for kidney metastasis has no effect on survival and quality of life, and a nephrectomy may also compromise the choice of chemotherapy agents that require renal clearance; thus, a careful evaluation of renal function is necessary before a nephrectomy. At present, kidney metastasis should be regarded as an advanced metastatic disease, and aggressive chemotherapy, including target therapy, should prolong survival and improve the quality of life. However, when a synchronous or a metachronous renal tumor is suspected, a nephrectomy should be performed for accurate diagnosis and treatment.