Clinicopathological features and prognosis of fumarate hydratase deficient renal cell carcinoma / 北京大学学报(医学版)

OBJECTIVE@#To investigate the clinicopathological features and prognosis of fumarate hydratase deficient renal cell carcinoma (FH-RCC).@*METHODS@#Immunohistochemical (IHC) staining was used to detect the expression of fumarate hydratase (FH) in tumor tissues of 109 different types of renal cell carcinoma (RCC) patients aged 60 years and younger from the Department of Urology of Peking University First Hospital from January 2013 to December 2019. The clinicopathological data and prognosis of FH-RCC were collected and analyzed.@*RESULTS@#There were eleven patients with FH-negative expression. Seven were males and four females. The age of onset ranged 16-53 years (mean age: 36.7 years), and four female patients all had a history of uterine leiomyoma. Only one first-degree relative of one patient had renal cancer, and none of the patients had a history or family history of cutaneous leiomyomas. The diameter of the tumor was 2.1-12.0 cm (mean: 8.83 cm). Renal sinus or perirenal fat invasion was seen in nine cases, tumor thrombus in renal vein or inferior vena cava in six cases, lymph node metastasis in seven cases, adrenal gland invasion in four cases and splenic capsule invasion in one case. The cases were initially diagnosed as type Ⅱ papillary RCC (7/49, 14.3%), collecting duct carcinoma (2/9, 22.2%) and unclassified RCC (2/51, 3.9%). Tumor histopathology mostly showed a mixture of different structures, such as papillary, tubular cystic, solid, and so on. The most common histological structures were papillary (9/11, 81.8%) and tubular (8/11, 72.7%). Three cases had sarcomatoid areas. At least focal eosinophilic nucleolus (WHO/grades Ⅲ-Ⅳ) and perinuclear halo could be seen in all cases. Immunohistochemical (IHC) stains of most tumors were negative for CA9, CD10 and CK7. The results of fluorescence in situ hybridization (FISH) showed that there was no translocation or amplification of TFE3 gene in two cases with TFE3 IHC expression. All the patients were followed up for 11-82 months. Mean survival was 24 months. Five cases died of distant metastasis 9-31 months after operation (mean: 19 months), and five of the six patients alive had became metastatic.@*CONCLUSION@#Morphologically, FH-RCC overlaps with many types cell RCC. A mixture of papillary and tubular cystic arrangement is the most common growth pattern of FH-RCC. At least focally large and obvious eosinophilic nucleoli are an important histological feature of this tumor. The negative expression of FH can help to confirm the diagnosis. Young female RCC patients with uterine leiomyomas should be suspected of FH-RCC. Some FH-RCC cases lack clinical evidence. The suspicion raised by pathologists based on histological characteristics is often the key step to further genetic testing and the final diagnosis of the tumor.

A novel mutation in DKC1 gene in a patient with dyskeratosis congenita / 中华皮肤科杂志

Objective To detect the mutation in DKC1 gene in a patient with dyskeratosis congeni- ta.Methods Fifteen exons of DKC1 gene were amplified by polymerase chain reaction (PCR),and the products were screened for mutations by denaturing high performance liquid chromatography (DHPLC) technology,then DNA sequencing was performed for abnormal exons as shown by DHPLC.The gene muta- tions were verified within 100 unrelated male individuals without dyskeratosis congenita.Results An ab- normal DHPLC elution peak was found in exon 12 of DKC1 gene of the patient,but not in other family members or normal individuals.DNA sequencing showed a 1236G→T transition in DKC1 gene in the pa- tient,which resulted in a 412W→C substitution in DKC1.No mutation was found in other family members and normal individuals.Conclusion The 1236G→T transition in the patient is a novel mutation in DKC1 gene,which could be a causative factor of dyskeratosis congenita.