Radiologic and clinicopathologic findings of peripheral primitive neuroectodermal tumors.

BACKGROUND: Primitive neuroectodermal tumors (PNETs) constitute a rare type of malignant neuroectodermal tumors that have chromosomal translocations identical to Ewing's sarcoma (ES), and the characteristics of this disease remain unclear. PURPOSE: To describe the clinical, radiological, and pathological features of peripheral PNETs (pPNETs) to enhance their recognition. MATERIAL AND METHODS: The clinical, imaging, and pathologic findings of 35 patients with pPNETs were retrospectively reviewed, all being confirmed by biopsy or surgical pathology. All 35 patients had preoperative computed tomography (CT) examinations; 10 patients had preoperative magnetic resonance imaging (MRI) studies. RESULTS: Of 35 pPNET patients, 54.3% had a primary tumor in soft tissue, the others in bone. On plain CT images, 33 lesions demonstrated heterogeneous hypodense masses with multiple lamellar lower density, and with osteolytic destruction if the tumor originated in bone. Calcification was only found in five lesions arising in soft tissue. All lesions enhanced heterogeneously with varying areas of cystic changes, and all lesions in bone and 52.6% of lesions in soft tissue showed ill-defined margins after contrast administration. On MRI, these tumors appeared in conjunction with osteolytic bone destruction and irregular soft tissue masses iso- to hypointense to skeletal muscle on T1-weighted images and showed heterogeneously high intensity on T2-weighted images. All lesions enhanced heterogeneously with cystic changes. Homer-Wright rosettes were observed in 15 lesions, and 97.1% lesions were positive for CD99 in histopathological results. CONCLUSION: pPNETs can involve any part of the body, and a large, ill-defined, aggressive soft tissue mass and heterogeneous enhancement with or without osteolytic bone destruction on CT or MR images could suggest the diagnosis.

[HRCT and pathology for nodules in cadaveric lung with coal workers' pneumoconiosis].

OBJECTIVE: To evaluate imaging of high-resolution computed tomography (HRCT) for nodules of cadaveric lungs of coal workers' or coal workers with coal workers' pneumoconiosis (CWP) and to determine types of small nodules of CWP and dust speckle based on CT-pathologic correlation. METHODS: Thirty-two entire lung specimens were available from autopsy of the patients with CWP and coal workers occupationally exposed to coal dusts. They comprised 25 workers without CWP, 3 patients with 0+ stage and 4 patients with I stage. Thirty-two lung specimens were inflated and fixed by Heitzman's method, and underwent coronal single slice computed tomography (SSCT)/multi-slice computed tomography (MSCT) and HRCT scans. Gross specimens section (50 approximately 100 microm of slice thickness) and histological section (5 approximately 8 microm of slice thickness) were performed on seventeen pieces of 10 mm-thickness slices of lung specimen in thirteen cases. The nodules were divided into round, ill defined and stellate-shaped, and their distributions and relationships with pulmonary lobule were analyzed. RESULTS: The findings were as follows (1) 14 cases without CWP and 18 cases with CWP (including 5 cases with I stage 11 cases with II stage and 2 cases with III stage) were diagnosed by pathology. (2) Nodules were displayed on HRCT in 32 cases, among which 29 cases were verified by pathology. There was no significant difference between HRCT and pathology (chi2 = 0.5, 0.25 < P < 0.5). (3) Nodules of CWP on HRCT included well-defined round nodules, ill defined nodules and stellate-shape nodules. Twelve of fourteen round nodules on HRCT were pathologically typical ones. Twenty-six ill defined nodules on HRCT included 14 atypical ones, 11 dust macules and 1 typical one by pathology. Six dust macules and 3 atypical nodules were found by pathology in nine stellate-shape nodules on HRCT. (4) HRCT accurately displayed nodular distributions including nodules adjacent to small artery, thickened septa and subpleural regions. CONCLUSION: HRCT could display typical, atypical nodules and some dust macules presenting pathologic changes, as well as relationship between nodules and structure of pulmonary lobule.