Round cell liposarcoma of scrotum with indolent course in young adult.

Myxoid/Round cell liposarcoma accounts for one-half of all liposarcomas and occurs as the second most common subtype. Both myxoid and round cell types share clinical, histological features and are accepted to represent a spectrum of lesions ranging from pure myxoid to near completely round cell liposarcoma. Round cell liposarcoma is highly metastatic and is classified as high grade and poorly differentiated myxoid sarcoma. Typical non-round cell myxoid liposarcoma is less metastatic and has more favorable prognosis. Karyotypic study of myxoid and round cell liposarcomas reveal a characteristic reciprocal translocation t (12;16)(q13;p11) resulting in the fusion of CHOP gene with TLS gene in more than 90% of cases. Most masses within the scrotal sac arise from the testis proper, and less likely from the extratesticular tissue. Liposarcoma represents approximately 20% of malignant extratesticular neoplasms, with the well differentiated subtype being the most common. Myxoid/round cell liposarcoma and round cell liposarcoma are rarely encounter in extratesticular soft tissue. We reported a rare case of round cell liposarcoma (high grade myxoid liposarcoma) of extratesticular tissue. To our knowledge, this is the first case of a large size (> 5cm) round cell liposarcoma arising from soft tissue within the scrotal sac of young adult with indolent course. Simple excision or enucleation are inadequate therapies and wide excision of the hemiscrotum including inguinal soft tissue and nodes is recommended. The role of retroperitoneal lymph node dissection and adjuvant chemotherapy remains controversial.

Identification of Tumor Suppressor Loci on the Long Arm of Chromosome 15 in Primary Small Cell Lung Cancer

Small cell lung cancer (SCLC) frequently shows a loss of heterozygosity (LOH) on chromosome 15q. In order to define the commonly affected region on chromosome 15q, we tested 23 primary SCLCs by microsatellite analysis. By analyzing 43 polymorphic microsatellite markers located on chromosome 15q, we found that 14 (60.8%) of 23 tumors exhibited a LOH in at least one of the tested microsatellite markers. Two (14.3%) of the 14 tumors were found to have more than a 50% LOH on chromosome 15q. LOH was observed in five commonly deleted regions on 15q. Of those regions, LOH from D15S1012 to D15S1016 was the most frequent (47.8%). LOH was also observed in more than 20-30% of tumors at four other regions, from D15S1031 to D15S1007, from D15S643 to D15S980, from D15S979 to D15S202, and from D15S652 to D15S642. Four of the 23 tumors exhibited shifted bands in at least one of the tested microsatellite markers. Shifted bands occurred in 3.2% (29 of 914) of the loci tested. Our data suggests the presence of at least five tumor suppressor loci on chromosome 15q in SCLC, and further that these may play an important role in SCLC tumorigenesis.

Identification of Tumor Suppressor Loci on the Long Arm of Chromosome 4 in Primary Small Cell Lung Cancers

Recent cytogenetic studies have indicated that loss of the long arm of chromosome 4 is a frequent event in small cell lung cancer (SCLC), which suggests the presence of tumor suppressor genes there. To precisely map tumor-suppressor loci on chromosome 4q for further positional cloning efforts, we tested 15 primary SCLCs. Forty two polymorphic microsatellite markers located on chromosome 4q were used in the microsatellite analysis. We found that 12 (80%) of the 15 tumors exhibited loss of heterozygosity (LOH) in at least one of the tested microsatellite markers, and that 3 (25%) of these 12 tumors exhibited a larger area of deletion on chromosome 4q. Frequent LOH, defined as occurring in more than 50% of the tumors, was observed in five commonly deleted regions on 4q, namely 4q24, 4q27-28.3, 4q33, 4q34.1, and 4q34.3-35.2. Of these 5, LOH at 4q33 was the most frequent (61.5%). Six (40%) of the 15 tumors exhibited shifted bands in at least one of the tested microsatellite markers. Shifted bands occurred in 3.7% (23 of 630) of the loci tested. Our data demonstrated that at least five tumor-suppressor loci exist on the long arm of chromosome 4 and that they may play an important role in the development and progression of primary small cell lung cancer tumorigenesis.

Familial aggregation of cancer in patients with bronchogenic carcinoma.

History of cancer among first degree relatives was obtained in 124 patients with bronchogenic carcinoma [probands] and 248 controls, and differences in familial aggregation evaluated by calculation of odds ratio [OR] and their 95 percent confidence intervals [95% CI]. Probands were more likely than controls to have relatives with cancers [OR 1.27, 95% CI 0.49-3.10], both among smokers and nonsmokers [OR 1.31, 95% CI 0.27-6.79 and OR 1.21, 95% CI 0.12-6.16 respectively]. Sisters of probands were particularly at a higher risk [OR 8.72, 95% CI 0.85-430.08]. A genetic component, possibly independent of smoking habits, may be important in the causation of lung cancer.

Polymorphism of the CYP1A1 and glutathione-S-transferase gene in Korean lung cancer patients

The levels of expressions and catalytic activities of cytochrome P450 (CYP1A1) and glutathione-S-transferase class mu (GSTM1) enzymes in lungs and their metabolic balance may be an important determinant host factor underlying lung cancer. Genetic differences in metabolism, MspI restriction sites, Ile-Val polymorphism of CYP1A1 gene, and the null genotype of GSTM1 have been reported to be associated with susceptibility to lung cancer. The present studies were undertaken to establish frequencies of the polymorphic genotypes of CYP1A1 and GSTM1 in Koreans, and to evaluate linkage disequilibrium of the genotypes associated with higher lung cancer risks among Koreans. GSTM1(-) genotype was found in 52% of control subjects, whereas it was found in 55% of lung cancer patients. The allelic variants in CYP1A1 were distributed differently in lung cancer patients and controls. The heterozygous genotype frequency of the MspI site in lung cancer patients (53%) was higher than in controls (49%). The frequency of Ile/Val genotype of CYP1A1 was low in lung cancer patients, which are mostly squamous cell carcinoma.