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Peripheral malignant neuroectodermal tumors are rare and aggressive small-cell tumors seen predominantly in children and young adults. Mediastinal location is very uncommon. A mediastinal primitive neuroectodermal tumor was diagnosed in a 27-year-old man. Despite treatment combining surgery, radiotherapy and chemotherapy, disease recurred locally along with lungs, spinal and epidural metastases, leading to death. CT and MRI examinations show heterogeneous masses with necrosis, hemorrhage and intense enhancement after Gadolinium injection. The CT and MRI findings are not specific and the diagnosis is based on pathologic, immunohistochemical and electron microscopic features. Although uncommon, peripheral neuroectodermal tumor should be considered in the differential diagnosis of posterior mediastinal masses in children and young adults.

We report two cases of bone and joint amyloidosis involvement related to plasma cell dyscrasia. The radiographic appearances mimic numerous benign or malignant diseases. MR imaging shows a diffuse low signal in T1 and an heterogeneous low or mild low signal in T2 weighted spin-echo sequence.

The effect of chlorozotocin [(CZT) CAS: 54749-90-5; 2-(3-(2-chloroethyl)-3-nitrosoureido)-D-gluco-pyranose] was studied on a series of tumor cells, cultured or extracted fresh primary or transplanted tumors, by means of clonogenic assay. The ability of most rat rhabdomyosarcoma cells to form colonies in soft agar was enhanced when exposed to the water-soluble nitrosourea chloride CZT. The tumor cells tested were derived from a) several primary tumors induced in WAG rats by colloidal nickel, then cultured and exposed to CZT early during in vitro passage; b) the 9-4 tumor, also Ni-induced but maintained in long-term culture; and c) the Ni-induced 9-4/0 tumor, maintained by transplantation in syngeneic rats. No inhibition of colony formation was observed in any of the cell lines even at high concentrations of CZT. Adriamycin, chosen as a control treatment, strongly inhibited the cloning efficiency (CE) of the tumor cells. In vivo, the weekly injection of 10 mg CZT/kg body weight into syngeneic rats bearing transplanted tumors led to an enhancement of lung metastasis formation. The CZT enhancement of CE of tumor cells and its relationship to increased in vivo tumor metastasis is discussed.

A previous study using a single injection of (chloro-2-ethyl)ribofuranosyl-3-nitrosourea has indicated the low acute hematotoxicity of this nitrosourea. However, because the hematotoxicity of nitrosourea is usually cumulative, we have studied the effect of injecting (chloro-2-ethyl)ribofuranosyl-3-nitrosourea (15 mg/kg) dissolved in 0.2 ml sterile oil C57BL X i.p. into DBA/2F1 mice for 5 consecutive weeks. The dose per injection represents the minimal dose necessary to show the maximal therapeutic efficacy on L1210 leukemia. Bone marrow cellularity and histology, spleen weight, bone marrow and splenic pluripotent stem cells, and colony-forming units committed to granulocyte-macrophage differentiation were measured 1, 2, 4, 7, and 14 days after the last injection in treated and control mice receiving oil only. No morphological or histological changes were found in the spleen and bone marrow of treated mice. In both organs, the number of splenic pluripotent hematopoietic stem cells decreased by about 1 log 1 day after the last injection but rapidly returned to normal values on Days 4 to 14. Granulocyte-macrophage-committed precursors were affected in both organs, at 20% of control values for bone marrow and 5% of control values for spleen on Day 1, with a transient and partial recovery on Day 4 followed by a second drop to 20 and 25% on Day 14. This effect on granulocyte-macrophage precursors contrasts with the absence of significant effect when the same treatment is used on peripheral white blood cell counts. Our results demonstrate that (chloro-2-ethyl)ribofuranosyl-3-nitrosourea belongs to the class of new nitrosoureas with low cumulative hematotoxicity.

Two hundred and nineteen patients with resected lung carcinoma were randomized 3 weeks after surgery between two treatment arms: a control group (110 cases) and an immunotherapy group (109 cases). The immunostimulant was a nonviable saprophytic mycobacterium, M. smegmatis, given monthly by subcutaneous injection in four sites. The two groups were equivalent in terms of prognostic factors, including a nonsignificant difference favoring the control group based on the N (node) classification. This interim analysis was carried out on June 1, 1981. Treatment comparison by the log-rank test did not show any significant differences between these two groups in regards to disease-free interval and overall survival. There was no significant difference between the two groups after stratification of the comparison according to the N classification or adjustment with a subset of eight prognostic parameters through the Cox model. The initially expected difference (20% 1-year survival) will probably not be achieved, given these interim results, but patients will continue to be treated and followed-up according to the protocol as to allow further evaluation of this nonspecific immunotherapy.