High-grade mucinous tubular and spindle cell carcinoma: comparative genomic hybridization study

Mucinous tubular and spindle cell carcinoma (MTSCC) has recently been integrated into the World Health Organization classification. Although MTSCC is generally a low-grade carcinoma, MTSCC with high-grade morphology has been recently reported. We present the first case of high-grade MTSCC with comparative genomic hybridization findings. A 60-year-old Japanese man presented with weight loss and general fatigue. He underwent radical nephrectomy because of the clinical diagnosis of renal cancer. Histologic examination of renal tumor showed findings of high-grade MTSCC. Comparative genomic hybridization analysis showed gain of chromosomes 1q, 7, 16, 19q, and Y and loss of chromosomes 1p, 6p, 8p, 11q (del(11)(q23)), and 13. G-band karyotype showed gain of chromosomes 2, 3, 5, 7, 12, 16, and 20 and loss of chromosome 15. Results of our molecular genetic analysis support the idea that high-grade MTSCC is a real counterpart of low-grade MTSCC. There is no evidence to designate such tumors as unclassified renal cell carcinoma.