Abstract Background There are well known cases of hybrid tumors of chromophobe renal cell carcinoma (RCC) and oncocytoma in kidney, where both tumors have the same cell of origin – intercalated cell of the collecting duct. However, collision tumors composed of neoplasms originating from different cell lineages such as oncocytoma and papillary RCC are extremely rare. Herein, we made a collective literature review of reported cases of collision tumors composed of oncocytoma and papillary RCC, adding a case that we recently experienced. Material and methods A PubMed database was search for collision tumors of the kidney composed of oncocytoma and papillary RCC and a collective literature review was made. To this cohort, we also added a recently encountered case with similar, confirmed by immunohistochemistry, morphological features. Results To date 8 cases of a collision tumor composed of papillary RCC and oncocytoma have been described in the literature. All of them had a smaller papillary RCC component present within a larger oncocytoma. Conclusion Because of a few cases of such a collision tumors reported, it is difficult to make classification and right clinical management of these patients. None of the reported cases had tumor recurrence or progression on a follow-up. The presence of only small portion of papillary RCC in a large oncocytoma raises a possibility of under-sampling of malignant component in large oncocytomas in core biopsy or surgically resected specimens. We recommend better sampling, particularly at the periphery of otherwise classic oncocytomas to unveil this possible association. Highlights • In hybrid tumors of kidney composed of chromophobe renal cell carcinoma (RCC) and oncocytoma, both tumors have the same cell of origin – intercalated cell of the collecting duct. • However, observing collision tumors, tumors composed of cells of different lineages is extremely rare. • To date only 8 cases of a collision tumor composed of papillary RCC and oncocytoma have been described in the literature. • We made a collective literature review of collision tumors in the kidney composed of oncocytoma and papillary RCC, adding a case that we recently experienced. • We recommend generous sampling at the periphery of otherwise classic oncocytomas or papillary growth areas in oncocytomas to unveil this possible association.

We report a study of 27 patients with small cell osteosarcoma (SCO), 17 from the M. D. Anderson Cancer Center (MDAH) and ten from the Pediatric Oncology Group (POG). There were 12 male patients and 15 female patients; 19 were white, five were black, and three were Hispanic. They ranged from 6 to 28 years of age with a median of 14 years. Histologically there were three patterns: Ewing's-like, lymphoma-like, and spindle cell. All cases showed osteoid formation and a few had chondroid areas. There was cytoplasmic glycogen in ten cases. Initial treatment for MDAH patients included intraarterial infusion of cisplatin in ten, amputation in four, partial mandibulectomies in two, and biopsy with local radiotherapy and systemic chemotherapy in one. All POG patients had resection or amputation followed by adjuvant chemotherapy. Twelve patients are alive, of whom nine have had significant follow-ups for 25 to 90 months. Fourteen patients are dead of lung, spine, and brain metastases from 1 to 23 months after initial diagnosis. One patient is alive with lung relapse at 4 months. In summary, SCO is a high-grade variant of osteosarcoma, with an incidence of up to 4% of all osteosarcomas, that affects patients of the same age group and has the same anatomic location as conventional osteosarcoma. Currently, SCO appears to have a prognosis that is the same as or slightly worse than that of conventional osteosarcoma. Furthermore, although intraarterial infusion is effective for the primary tumors in the bone, distant metastases are difficult to control.

Summary Primary renal collision tumors composed of 2 histologically distinct components are rare with only isolated case reports in the medical literature. Oncocytoma is a benign renal neoplasm, which is thought to originate from distal tubular epithelial cells. Mucinous tubular and spindle cell carcinoma (MTSCC) of kidney is a rare, relatively recently described renal neoplasm that was first included in the 2004 World Health Organization renal cell carcinoma (RCC) classification as a distinct entity. Current studies suggest that the tumor originates from the proximal nephron, although it is still controversial. The presence of concurrent oncocytoma with conventional (clear cell) RCC, chromophobe RCC, and papillary RCC has been previously described. However, the association of oncocytoma with MTSCC has not yet been reported to our knowledge. Herein, we report the first case of a renal collision tumor composed of oncocytoma and MTSCC. Highlights • A collision tumor is coexistence of histologically distinct tumors in the same site. • The first case of renal collision tumor of oncocytoma and mucinous tubular and spindle cell carcinoma is reported. • Oncocytoma is benign, and mucinous tubular and spindle cell carcinoma is a malignant neoplasm with indolent behavior.

Tumor specimens from 24 children under 15 yr of age were studied. The children had osteosarcoma and received intra-arterial infusions of cis-platinum before resection or amputation. There were 13 boys and 11 girls, and the median age was 12 yr. Fifteen lesions were located in the femur 4 in the humerus, 3 in the tibia, 1 in the pubis and 1 in the radius. Sixteen patients underwent diagnostic needle biopsies and the remainder, open biopsies. Patients (11) had excellent tumor response, with > 90% tumor destruction in 6 and 65-75% in 5. One patient had 50% tumor destruction, and in 9 patients the response was insignificant. Two patientss had good clinical responses to treatment and refused limb amputation; 1 additional patient died of the disease without amputation or resection. The systematic study of pathology specimens is being undertaken to determine the utility of such a study as a guide to the selection of adjuvant chemotherapy. Patients in whom no responses are obtained should receive alternative treatment, and those in whom responses are optimal should retain the original agent in their adjuvant chemotherapy regimen.

The U. S. economy and financial system have strengthened notably in recent years and in a mutually reinforcing way. U. S. monetary and regulatory policy both need to be tailored to domestic conditions. The Fed is also mindful of the international effects of its policies, given the central place of the U. S. in the global financial system, and the potential for spillbacks to the U. S. economy and financial system. Effective communication with market participants and policymakers is important. The opportunity for dialogue is what makes conferences such as this one valuable.