Small-Cell Pediatric Tumors: Histology, Immunohistochemistry, and Electron Microscopy

Primary Ewing's Sarcoma of the Spine in a Two-Year-Old Boy

Ewing's Sarcoma (ES) is a highly malignant bone tumour. It may involve any part of the skeleton but the most frequent parts are the ilium and diaphysis of femur and tibia (Alfeeli et al., 2005; Zhu et al., 2012). Primary ES of the spine is extremely rare (Yan et al., 2011). It accounts for only 3.5 to 14.9 percent of all primary bone sarcomas. The age of presentation ranges from 12 to 24 years (median 21 years) (Ferguson, 1999; Sharafuddin et al., 1992; Klimo Jr. et al., 2009). We report an unusual case of primary ES of the spine in a two-year-old boy, who presented to us with paraparesis and features of cauda equina syndrome. MRI scan showed a tumour mass arising from the pedicle of L4 vertebra invading the spinal canal. Tc-99 bone scan showed increased tracer uptake in L4 vertebra and normal tracer uptake elsewhere in the skeleton. After reaching the diagnosis of a space occupying lesion invading the lumber spinal canal, we performed a decompressive laminectomy and a biopsy was sent which confirmed the diagnosis of ES. Immunohistochemistry showed tumour cells staining positive for CD-99 (specific stain for ES). Gene testing showed an EWS-FLI 1 chimera. Surgery was followed by good improvement in motor signs. The child was then referred to a specialized oncotherapy centre for further treatment, radiation, and chemotherapy. To the best of our knowledge, we are the first to report primary ES of the spine at the age of two years.

Primary Ewing's Sarcoma of Frontoparietal Bone with Major Soft Tissue Extension: An Unusual Presentation and Review of the Literature

An 11-year-old girl presented with progressively increasing swelling in scalp of 8-month duration with no neurological deficit. Local examination showed a hard swelling that seemed to be arising from frontal bone. General and systemic examination was normal. MRI revealed a well-defined lytic lesion in left frontoparietal bone with a subgaleal component. The patient was operated upon and excision of tumor with reconstruction of skull was done. Histopathological examination showed a monomorphic small round cell tumor of bone infiltrating into the subcutaneous tissue. Immunohistochemical stain showed diffuse immunopositivity for MIC-2 in tumor cells, thus final diagnosis of Ewing's sarcoma was made. The patient was kept for follow up for 3 months and had no symptoms.

Primary Ewing’s sarcoma of the spine: case report

Primary malignant sarcomas of the spine are extremely rare. Because of biological heterogeneity, these tumors have variable sensitivity to radiation and chemotherapy. Adequate local control through complete tumor removal is an important therapeutic goal. However, aggressive resection of tumors in the spinal column must be coupled with restoration of spinal column stability and minimization of neural deficits. The balance of these factors makes treatment of primary sarcomas of the spine challenging, and dictates an individual approach to treatment. We report on a 18 years old man with primary Ewing's sarcoma of the nonsacral spine. The clinical picture and imaging characteristics were analyzed as well as the management modalities and outcome.

Hepatoblastoma: cytomorphologic characteristics in serious cavity fluids

BACKGROUND

Hepatoblastoma (HBL) represents the most common primary hepatic tumor in children. Although the cytologic features of this tumor have been amply elucidated on fine-needle aspiration, exfoliative cytomorphologic characteristics have not been reported. The authors reviewed the cytopathologic features of six serous cavity fluids (SCF) from four patients with histologically proven HBL.

METHODS

Five of the specimens evaluated were peritoneal fluids, and one specimen was pleural fluid from a patient with suspected pulmonary metastasis. Slides were prepared by cytocentrifugation and stained with Diff-Quik and Papanicolaou stains. The cytomorphologic features of each specimen were characterized, subclassified, and correlated histopathologically.

RESULTS

All specimens showed hypercellular smears in a relatively clean background. Mixed embryonal and fetal subtypes of HBL disclosed three-dimensional clusters of neoplastic cells that formed straight or branched cords and acinus-like structures. The cells were moderately pleomorphic and had high nuclear-to-cytoplasmic (N/C) ratios. Occasional cells had eccentrically placed nuclei and vacuolated cytoplasm. Numerous mitotic figures were present. Rare intranuclear inclusions were noted. The anaplastic (small cell) subtype of HBL showed tight clusters of small, round, primitive cells with hyperchromatic nuclei, high N/C ratios, and prominent nuclear molding. In addition, there were numerous single cells with naked nuclei, often in an Indian-file configuration. Bile pigment, osteoid, and other mesenchymal components were absent in all specimens.

CONCLUSIONS

The cytomorphologic features of HBL in SCF are quite characteristic. Although the differential diagnosis includes other childhood small, round, blue cell tumors and hepatocellular carcinoma, the above findings in the appropriate clinical-radiologic setting warrant a diagnosis of HBL.

Second malignancies after ewing tumor treatment in 690 patients from a cooperative German/Austrian/Dutch study

BACKGROUND

Ewing tumor treatment involves high cumulative doses of alkylating agents and topoisomerase inhibitors, drugs capable of inducing second cancers. We analyzed the second cancer risk in a large cohort of consistently treated patients.

PATIENTS AND METHODS

Six hundred ninety Ewing tumor patients were treated between 1992 and 1999 with local therapy and vincristine. doxorubicin, ifosfamide and/or cyclophosphamide, and antinomycin D, with or without etoposide as a randomized question. Second cancer incidences were estimated by competing risk analyses; standardized incidence ratios (SIR) in comparison to registry data were compiled.

RESULTS

After a median observation time of 56 months (32 months for survivors), 6 of 690 patients had developed second cancers: MDS/AML, two, ALL/NHL, two, squamous cell carcinoma, one, liposarcoma, one. SIR were increased 20-30 fold in comparison to the general population. The cumulative second cancer risk five years after diagnosis of the Ewing tumor was 0.0093 for the total group, zero for patients without etoposide, and 0.0118 with etoposide. Additional phase II high-dose therapy increased the risk to 0.0398 after five years.

CONCLUSIONS

The second cancder risk observed was in the range to be expected in cancer survivors. High-dose therapy, and less markedly, etoposide, may contribute to the overall second cancer risk.

Localized Ewing tumor of bone: final results of the cooperative Ewing's Sarcoma Study CESS 86

PURPOSE

Cooperative Ewing's Sarcoma Study (CESS) 86 aimed at improving event-free survival (EFS) in patients with high-risk localized Ewing tumor of bone.

PATIENTS AND METHODS

We analyzed 301 patients recruited from January 1986 to July 1991 (60% male; median age 15 years). Tumors of volume >100 mL and/or at central-axis sites qualified patients for "high risk" (HR, n = 241), and small extremity lesions for "standard risk" (SR, n = 52). Standard-risk patients received 12 courses of vincristine, cyclophosphamide, and doxorubicin alternating with actinomycin D (VACA); HR patients received ifosfamide instead of cyclophosphamide (VAIA). Tumor sites were pelvis (27%), other central axis (28%), femur (19%), or other extremity (26%). The initial tumor volume was <100 mL in 33% of cases and > or =100 mL in 67%. Local therapy was surgery (23%), surgery plus radiotherapy (49%), or radiotherapy alone (28%). Event-free survival rates were estimated by Kaplan-Meier analyses, comparisons were done by log-rank test, and risk factors were analyzed by Cox models.

RESULTS

On May 1, 1999 (median time under study, 133 months), the 10-year EFS was 0.52. Event-free survival did not differ between SR-VACA (0.52) and HR-VAIA (0.51, P =.92). Tumor volume of >200 mL (EFS, 0.36 v 0.63 for smaller tumors; P =.0001) and poor histologic response (EFS, 0.38 v 0.64 for good responders; P =.0007) had negative impacts on EFS. In multivariate analyses, small tumor volumes of <200 mL, good histologic response, and VAIA chemotherapy augured for fair outcome. Six of 301 patients (2%) died under treatment, and four patients (1.3%) developed second malignancies.

CONCLUSION

Fifty-two percent of CESS 86 patients survived after risk-adapted therapy. High-risk patients seem to have benefited from intensified treatment that incorporated ifosfamide.

Primitive neuroectodermal tumor of the chest wall in a patient with Jeune's syndrome and renal transplant

Jeune's syndrome is a rare autosomal disorder characterized by osseous dysplasia, fetal respiratory distress, and renal failure in later life. We describe a 27-year-old man with Jeune's syndrome who underwent renal transplantation and 6 years later developed a sarcoma (primitive neuroectodermal tumor [PNET]) in the soft tissue of the chest wall, a principal site of dysplasia in this disorder.

Use of the uranaffin reaction in the identification of neuroendocrine granules

This overview emphasizes the utility of the uranaffin reaction in the diagnosis of tumors derived from neuroendocrine cells. The history, cell organelle specificity, tissue specificity, pH requirements, and detailed procedure of the uranaffin reaction is provided. Uranaffin-positive granules are also identified within the NS granules of the stem cell paraneuron (archiparaneuron) of coelenterates, and a hypothetical evolutionary scheme depicting the possible origins of the key biochemical features of the advanced mammalian NS granule is included. The role of nucleotides, a major component of true NS granules, is discussed. A possible intragranular function of ATP as a regulator of osmotic pressure and the extracellular physiologic effects of secreted intragranular nucleotides are discussed in some detail.

Value of cytogenetics in the differential diagnosis of the small round cell tumors of childhood

Small round cell tumors are among the most common problems in the differential diagnosis of cancer, even when more sophisticated histological techniques are utilized (Ezinger and Weiss: In Soft Tissue Tumors. St. Louis: CV Mosby, 1988, pp 668-683). Six cases of small round cell tumors are described the diagnosis of which was particularly difficult. Cytogenetic analysis provided useful information in all of them in making the definitive diagnosis. The reported cases stress the value of cytogenetic methods in approaching difficult diagnostic problems.

Immunohistochemical study of childhood rhabdomyosarcomas and related neoplasms. Results of an Intergroup Rhabdomyosarcoma study project

The authors assessed a panel of immunohistochemical stains against 109 pediatric solid tumors, primarily rhabdomyosarcomas, under the auspices of the Intergroup Rhabdomyosarcoma Study. Fresh tumor tissue received from participating organizations was divided into portions that were either frozen or fixed in formalin, alcohol, or B5. Immunostaining was performed by the avidin-biotin complex method using monoclonal antibodies to desmin, neurofilaments, vimentin, cytokeratin, and leukocyte common antigen on cryostat sections. Tissue was also embedded in paraffin and stained with antimuscle-specific actin (MSA) and polyclonal antibodies to desmin, creatine kinase M subunit (CKM), myoglobin, and neuron-specific enolase (NSE). Antidesmin staining of cryostat sections was the most sensitive indicator of rhabdomyosarcoma (58 of 62 specimens positive). Results with this reagent in alcohol-fixed and formalin-fixed tissue were similar (46 of 56 positive versus 43 of 56 positive, respectively) and comparable with results with anti-MSA in formalin-fixed tissue (43 of 55 positive). However, the proportion of cells stained by antidesmin was higher in alcohol-fixed tissue than in formalin-fixed tissue. Staining with antimyoglobin and anti-CKM was much less satisfactory, with positivity rates of 17 of 37 and 11 of 57, respectively, in formalin-fixed rhabdomyosarcomas. Immunostaining of muscle markers revealed evidence of myogenesis in six undifferentiated sarcomas and in two sarcomas with inadequate histologic study on hematoxylin-eosin-stained sections. However, positivity was also noticed in samples of fibromatosis, Wilms' tumor, ectomesenchyoma, peripheral primitive neuroectodermal tumor, renal rhabdoid tumor, myositis ossificans, malignant fibrous histiocytoma, and embryonal sarcoma of the liver. The authors conclude that combined use of antidesmin and anti-MSA enhances the diagnosis of childhood sarcomas, especially when employed with other techniques such as electron microscopic study.

A contemporary view of neoplasms in children. The pathologist's perspective

The diagnosis of childhood malignancy is a complex endeavor that requires the cooperation of the clinician and pathologist. On occasion, potentially problematic situations arise when a biopsy cannot answer all of the questions or is nondiagnostic. Delays may occur before a final diagnosis is possible in an especially complicated case that requires several time-consuming studies. The pathologist should appreciate the pressure placed on the clinician to initiate treatment and, in turn, the clinician should realize that several steps are necessary before the pathologic examination can be completed.

Vasoactive intestinal peptide receptor regulation of cAMP accumulation and glycogen hydrolysis in the human Ewing's sarcoma cell line WE-68

This study describes functional characteristics of receptors for vasoactive intestinal peptide (VIP) on human Ewing's sarcoma WE-68 cells. These characteristics include 125I-VIP binding capacity, cellular cAMP generation, glycogen hydrolysis, and pharmacological specificity. Binding studies with 125I-VIP showed specific, saturable, binding sites for VIP in WE-68 cells. Scatchard analysis revealed the presence of a single class of high-affinity binding sites that exhibited a dissociation constant (Kd) of 90 pM and a maximal binding capacity (Bmax) of 24 fmol/mg of protein. VIP and VIP-related peptides competed for 125I-VIP binding in the following order of potency: human (h) VIP greater than human peptide with N-terminal histidine and C-terminal methionine (PHM) greater than chicken secretin much greater than porcine secretin. Glucagon and the C-terminal fragments VIP[10-28] and VIP[16-28] and the VIP analogue (D-Phe2)VIP did not inhibit 125I-VIP binding. Addition of hVIP to WE-68 cells provoked marked stimulation of cAMP accumulation, hVIP stimulated increases in cAMP content were rapid, concentration-dependent, and potentiated by 3-isobutyl-l-methylxanthine (IBMX). Half-maximal stimulation (EC50) occurred at 150 nM hVIP. The ability of hVIP and analogues to stimulate cAMP generation paralleled their potencies in displacing 125I-VIP binding. (D-Phe2)VIP, VIP[10-28], VIP[16-28], and (p-Cl-D-Phe6, Leu17)VIP, a putative VIP receptor antagonist, affected neither basal cAMP levels nor hVIP-induced cAMP accumulation. WE-68 cell responses to hVIP were desensitized by prior exposure to hVIP. Desensitization to hVIP did not modify the cAMP response to beta-adrenergic stimulation, and beta-adrenergic agonist desensitization did not modify responses to hVIP. hVIP also induced a time- and concentration-dependent hydrolysis of 3H-glycogen newly formed from 3H-glucose in WE-68 cultures. hVIP maximally decreased 3H-glycogen content by 36% with an EC50 value of about 8 nM. The order of potency of structurally related peptides of hVIP for stimulation of glycogenolysis correlated with their order of potency for inhibition of 125I-VIP binding. IBMX potentiated the glycogenolytic action of hVIP and PHM. The simultaneous presence of the calcium channel antagonist verapamil or the calcium ionophore A 23187 did not influence the glycogenolytic and cAMP stimulatory effects of hVIP. Collectively, these data indicate that Ewing's sarcoma (WE-68) cells are endowed with genuine VIP receptors which are coupled to the formation of cAMP that probably serves a second messenger role in stimulating glycogen hydrolysis in these cells in response to VIP.(ABSTRACT TRUNCATED AT 400 WORDS)