Malignant PEComa: a case report with emphasis on clinical and morphological criteria

<p>Abstract</p> <p>Background</p> <p>Malignant perivascular epitheliod cell tumor (PEComa) is a very rare entity composed of distinctive perivascular epitheliod cells with variable immunoreactivity for melanocytic and muscle markers. At present this neoplasm does not have a known normal cellular counterpart and the natural history is often unpredictable. Up to now, few cases of PEComa have been described and treatment modalities are still controversial, particularly in advanced conditions.</p> <p>Case presentation</p> <p>We handled the case of a 42-year-old man with unresectable PEComa of the abdomen. A 7 cm hepatic hypodense lesion between segment V and VIII of the liver and diffuse intraperitoneal nodules of 0,3-3,5 cm along the right subcapsular hepatic region, were documented by a CT scan. Radiological images showed abnormal lymph nodes of the right internal mammary chain and anterior mediastinum. The patient underwent an explorative laparotomy for uncontrolled intrabdominal hemorrhage without a well-defined preoperative tumor diagnosis. At surgery, multiple lobulated nodules containing hemorrhagic fluid on the liver surface, peritoneum and omentum were confirmed. The procedure had a palliative intent and consisted of hemostasis, hematomas evacuation and omentectomy. The diagnosis of PEComa was made after surgery on the basis of morphological and immunohystochemical criteria. Radiological and intra operative findings suggest that the mass has an hepatic origin with diffuse involvement of hepatic capsule and suspensory ligaments. The patient received medical support care with blood and plasma transfusions. In our experience, PEComa was clinically malignant, leading to a fatal outcome 25 days after hospital admission of patient.</p> <p>Conclusions</p> <p>Here we report and discuss the peculiar clinical, radiological and morphological presentation of unresectable PEComa. Although in the majority of the reported series, PEComas show a more better prognosis, our case presents with a particular aggressive biological behaviour. The importance of a correct preoperative diagnosis, the need for more effective targeted therapies based on tumor molecular knowledge and evidence-based clinical studies are emphasized together with a revision of the concerning scientific literature.</p

Thymoma calcification: Is it clinically meaningful?

Among anterior mediastinal lesions, thymoma is the most common. Thymomas are tumors of thymic epithelial cell origin that are distinguished by inconsistent histological and biologic behavior. Chest imaging studies typically show a round or lobulated tumor in the anterior mediastinum. Calcifications in thymomas are classically punctuate or amorphous, positioned within the lesion. Chest computed tomography (CT) features suggesting higher risk thymoma consist of tumor heterogeneity, vascular involvement, lobulation, pulmonary nodules, lymphadenopathy, and pleural manifestations. Imaging findings have an imperfect ability to predict stage and prognosis for thymoma patients. Our objective is to highlight the clinical implications of thymoma calcifications on the diagnosis, clinical manifestation and prognosis. A pubmed and google search was performed using the following words: thymoma calcification, calcified thymus, mediastinal calcification, anterior mediastinal calcification, and calcified thymoma. After reviewing 370 articles, 32 eligible articles describing thymoma calcifications were found and included in this review. Although the presence of thymus calcifications was more common in patients with invasive thymomas, they were present in significant portion of non-invasive thymomas. The presence of calcifications was not a significant factor in differentiating between benign and malignant thymoma. As a result, the type, location, size or other characteristics of thymus gland calcifications were not relevant features in clinical and radiologic diagnosis of thymoma. The histopathological diagnosis is still the only possible way to confirm the neoplastic nature of thymoma. All types of thymomas should be evaluated and managed independently of the presence of calcifications

Propagation of RML Prions in Mice Expressing PrP Devoid of GPI Anchor Leads to Formation of a Novel, Stable Prion Strain

PrPC, a host protein which in prion-infected animals is converted to PrPSc, is linked to the cell membrane by a GPI anchor. Mice expressing PrPC without GPI anchor (tgGPI- mice), are susceptible to prion infection but accumulate anchorless PrPSc extra-, rather than intracellularly. We investigated whether tgGPI− mice could faithfully propagate prion strains despite the deviant structure and location of anchorless PrPSc. We found that RML and ME7, but not 22L prions propagated in tgGPI− brain developed novel cell tropisms, as determined by the Cell Panel Assay (CPA). Surprisingly, the levels of proteinase K-resistant PrPSc (PrPres) in RML- or ME7-infected tgGPI− brain were 25–50 times higher than in wild-type brain. When returned to wild-type brain, ME7 prions recovered their original properties, however RML prions had given rise to a novel prion strain, designated SFL, which remained unchanged even after three passages in wild-type mice. Because both RML PrPSc and SFL PrPSc are stably propagated in wild-type mice we propose that the two conformations are separated by a high activation energy barrier which is abrogated in tgGPI− mice

Diagnostic accuracy and complication rate of CT-guided fine needle aspiration biopsy of lung lesions: a study based on the experience of the cytopathologist.

BACKGROUND: CT-guided transthoracic needle biopsy is a well-established technique for the diagnosis of focal lung lesions. Fine needle aspiration biopsy (FNAB) requires the presence of a cytopathologist on-site to assess the adequacy of samples. For this reason FNAB is less and less used, and core biopsy is the first-line procedure when an experienced cytopathologist is not immediately available. PURPOSE: To evaluate the accuracy and complication rate of CT-guided FNAB of lung lesions according to the experience of the cytopathologist on-site. MATERIAL AND METHODS: A total of 321 consecutive biopsies were considered. Immediate cytological assessment was performed by an experienced cytopathologist for the first 165 procedures (group A) and by two training pathologists for the remaining 156 biopsies (group B). At the time of FNAB the pathologist assigned a semiquantitative score (0-3) to each specimen to assess its diagnostic quality. All variables between the two groups were analyzed by chi-square and Student's t test. A P value <0.05 was considered statistically significant. RESULTS: For all procedures, overall diagnostic accuracy was 80% for cytology alone, with no statistical difference between the two groups for diagnostic accuracy and sample score assigned. In all, 75% of the cytological samples (75% group A, 74% group B) obtained a higher score with a specific diagnosis of histotype. A post biopsy pneumothorax was detected in 27% of biopsies (25% group A, 28% group B). Thirteen patients (4.0%) required chest tube insertion for treatment. For all cases, the pneumothorax rate was significantly affected by the number of samples obtained (P=0.02), but not by the pleural punctures (P=0.15). There was no statistically significant difference between the two groups concerning the number of needle passes and complication rate (P>0.05). CONCLUSION: The efficacy and safety of CT-guided FNAB is not significantly affected by the training level of the cytopathologist on-site. Moreover, the number of specimens obtained for each procedure is a risk factor for pneumothorax

Metronomic chemotherapy may be active in heavily pre-treated patients with metastatic adreno-cortical carcinoma.

Objective: the potential benefit of further chemotherapy approaches in patients with adrenocortical carcinoma (ACC) showing progressive disease after 2 chemotherapy lines is actually unknown. This study provide explorative information on the activity of metronomic chemotherapy in heavily pretreated ACC patients. Design and methods: we tested the activity of cytotoxic treatments administered on a metronomic schedule in metastatic ACC patients showing disease progression after treatment with gemcitabine and capecitabine scheme. Results: eight patients out of 28 consecutively enrolled in that trial were treated with several metronomic cytotoxic regimens. Six of them showed disease progression but 2 patients obtained a clear benefit. The first patient was treated with oral etoposide (50 mg daily) as the 6th line therapy and obtained a partial response lasting 24 months, while the second patient obtained a partial response lasting 10 months with metronomic oral cyclophosphamide (50 mg daily) as the 5th chemotherapy line. Both patients had sex hormone secreting tumors and were bearing a rather indolent ACC. Conclusions: the administration of several chemotherapy lines in advanced ACC patients cannot be routinely recommended outside of prospective clinical trials. Few patients with indolent tumors, however, may benefit from this approach. According to our experience, oral cyclophosphamide and oral etoposide may be used in this setting