Malignant small-cell tumor of the thoracopulmonary region: 'Askin tumor'

Primitive neuro-ectodermal tumor of the lung in an adult

A rare case of a thoracic primitive neuro-ectodermal tumor in an adult is presented here. In this case, wide excision surgical excision followed by chemotherapy and radiotherapy were delivered. But due to the rapid aggressive progression of the tumor, which is the characteristic of disease, the patient died within four months after the diagnosis.

Askin tumor with metastasis to the scalp: a histochemical, immunohistochemical and ultrastructural study

A 29-year-old woman presented with facial edema, and imaging disclosed a tumor extending from the anterior chest wall to the anterosuperior aspect of the mediastinum. Transbronchial cytology of the primary tumor and biopsy of the metastatic scalp lesion were performed. Histologically, the tumor consisted of closely packed small round cells. The neoplastic cells generally had round nuclei, finely dispersed chromatin, and small to prominent nucleoli. Histochemically, the cytoplasm of the neoplastic cells contained abundant glycogen and stained with Grimelius silver. Immunohistochemically, the neoplastic cell membranes reacted with CD99 (MIC2) and the neoplastic nuclei reacted with Fli-1, but various other markers, including lymphocyte and skeletal muscle markers, were not detected. No neoplastic cells were also reactive for chromogranin A, synaptophysin, and neurofilament. Ultrastructurally, some neoplastic cells had delicate cytoplasmic processes and contained membrane-bound dense core granules in the cytoplasm. Even if results are immunohistochemically negative for neuroendocrine markers, the combination of immunohistochemistry of CD99 (MIC2) and Fil-1 may be useful in diagnosing Askin tumor or its metastatic lesion.

Primitive neuroectodermal tumor of the pulmonary hilum in an adult

A rare case of a thoracic primitive neuroectodermal tumor in an adult is presented. In this case, the aggressive, rapid progression characteristic of the disease was evident.

Peripheral primitive neuroectodermal tumors. CT and MRI evaluation

The clinical, radiographic, and pathologic features of 17 patients with documented peripheral primitive neuroectodermal tumor (PNET) were evaluated in a retrospective study. The age at diagnosis ranged from 9 months to 46 years (median, 15.8 years). Primary sites of involvement were the abdomen (n = 8), extremities (n = 5), chest (n = 1), temporal bone (n = 1), maxilla (n = 1), and diploe (n = 1). At the time of diagnosis, six patients had distant metastases; all of these patients died, with an average survival of 8.8 months. Radiologic workup included standard radiographs, ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and bone scintigraphy. The radiographic appearance of these tumors was not specific for differentiation of PNETs from other types of bone and soft tissue tumors. The typical appearance resembled large non-calcified, soft tissue masses with cystic or necrotic areas. Heterogeneous enhancement with intravenous contrast agents was evident on CT, as was an intermediate signal intensity on Tl-weighted images and hyperintense signal on T2-weighted and STIR sequences. After gadolinium administration, variable enhancement was seen. MRI and CT were useful in predicting resectability, in detecting distant metastases, and in the evaluation of response to treatment. Surgery was performed in all cases, either for definitive diagnosis or for therapy. All patients received combined chemotherapy and radiotherapy and five patients received autologous bone marrow transplantation. Clinical follow-up was obtained over a mean period of 3 years (range 1 day to 6 years). Prognosis was poor with a median survival of 3.4 years. Our experience in 17 patients with peripheral neuroectodermal tumors indicates that although their radiologic features are non-specific, they should be included in differential diagnosis of soft tissue tumors of aggressive behavior, especially in a young age group. CT and MRI are useful in delineating the extent and resectability of tumor and in monotoring treatment.

Malignant peripheral neuroectodermal tumors in urology

During the past few years, a new tumor type has emerged in the pediatric and adolescent group of cancer patients, which has been designated malignant peripheral neuroectodermal tumor (MPNT). This tumor has some clinical and pathological signs in common with either soft-tissue sarcomas or classic Ewing's sarcoma, but is defined as a distinct entity because of its immunohistological characteristics. The tumor expresses neuronal markers, but the pattern varies: chromogranin, neuron-specific enolase, synaptophysin, protein S-100 and others. MPNT can occur in the urogenital region. The differential diagnosis on clinical grounds must include Ewing's and soft tissue sarcomas, and also Wilms' tumor and its variants. MPNT are often wide spread in the urogenital region when first diagnosed. Response to radiotherapy and combination chemotherapy is limited. Radical surgery is not always possible. The prognosis therefore remains rather poor at this time. A selection of MPNT patients is presented to demonstrate the various problems associated with this diagnosis. MRI and CT of all patients showed large tumors with direct infiltration of the surrounding structures. MRI is the best imaging modality for diagnosis and therapy monitoring in these tumors, because of its high soft-tissue contrast.

Recurrent intrapulmonary malignant small cell tumor of the thoracopulmonary region with metastasis to the oral cavity: review of literature and case report

Malignant small cell tumor of the thoracopulmonary region (MSCT) was first described in 1979 and has been referred to as the Askin tumor. This malignant neoplasm is a member of the peripheral primitive neuroectodermal tumor (PPNET) family and typically involves the periosteum, soft tissue, and extrapulmonary tissue of the thoracic wall. MSCT may also involve the lung parenchyma by local extension or may arise de novo in peripheral lung tissue. Local recurrence, abdominal involvement by tumor extravasation across the diaphragm, and skeletal metastatic disease are relatively common. However, metastasis to the head and neck region and in particular to the oral cavity is extremely rare. We present a recurrent intrapulmonary MSCT with metastasis to the oral cavity in an adolescent Hispanic boy, and review the literature regarding this member of the PPNET family. Differentiation from neuroblastoma may be made based on immunoreactivity for beta 2 microglobulin and HBA71 and lack of immunoreactivity for chromogranin in PPNET and MSCT. Ultrastructural features commonly seen in MSCT and PPNET are round to ovoid tumor cells with occasional cytoplasmic processes with relatively few pleomorphic dense core granules. These tumors lack the gangliocytic and Schwann cell differentiation that is characteristic of neuroblastoma. MSCT and PPNET have a common reciprocal cytogenetic translocation [t(11;22)q(24;q12)], which is shared with Ewing's sarcoma. Prognosis in MSCT is quite dismal, with a 2-year survival of 38% and a 6-year survival of only 14%.

Use of human dura in pediatric chest wall reconstruction after tumor resection

The most difficult aspect of the surgical treatment of chest wall tumors is reconstruction of the large residual defect. Materials that have been used include Marlex, Goretex, Vicryl, bone, metal, and fascia. The authors' successful experience with dehydrated human dura (Tutoplast) for moderate-size defects is described. A large Askin's tumor in a 13-year-old boy required resection of the right posterior aspect of the 9th to 11th ribs and the transverse process of T-10, the 12- x 12-cm thoracic defect was closed with dura. Partial soft-tissue coverage was obtained with the latissimus dorsi muscle. Although a scoliosis secondary to paraspinal muscle resection has developed, the chest wall is stable, without evidence of a flail chest, at 18 months of follow-up. A 6-year-old girl underwent left anterior chest wall resection of three ribs for an epithelioid sarcoma. Human dura and a myocutaneous flap were used for reconstruction, with good functional and cosmetic results at 16 months of follow-up. Dura is simple to use, has low antigenicity, and in experimental studies appears to be incorporated into the tissues, acting as a collagen matrix. For moderate-size chest wall defects, it appears to be an excellent alternative to synthetic prosthesis.

Malignant small cell tumour (Askin-Rosai) of the pericardium

An Askin-Rosai tumour presenting as effusive constrictive pericarditis is reported. A 2-D echocardiogram was strongly suggestive of a primary pericardial tumour, and multiple pericardial and pleural aspiration failed to yield malignant cells. The final diagnosis was made at autopsy. Primary pericardial Askin-Rosai tumour has not to our knowledge been previously reported.