An extremely high-altitude plume seen at Mars' morning terminator.

The Martian limb (that is, the observed 'edge' of the planet) represents a unique window into the complex atmospheric phenomena occurring there. Clouds of ice crystals (CO2 ice or H2O ice) have been observed numerous times by spacecraft and ground-based telescopes, showing that clouds are typically layered and always confined below an altitude of 100 kilometres; suspended dust has also been detected at altitudes up to 60 kilometres during major dust storms. Highly concentrated and localized patches of auroral emission controlled by magnetic field anomalies in the crust have been observed at an altitude of 130 kilometres. Here we report the occurrence in March and April 2012 of two bright, extremely high-altitude plumes at the Martian terminator (the day-night boundary) at 200 to 250 kilometres or more above the surface, and thus well into the ionosphere and the exosphere. They were spotted at a longitude of about 195° west, a latitude of about -45° (at Terra Cimmeria), extended about 500 to 1,000 kilometres in both the north-south and east-west directions, and lasted for about 10 days. The features exhibited day-to-day variability, and were seen at the morning terminator but not at the evening limb, which indicates rapid evolution in less than 10 hours and a cyclic behaviour. We used photometric measurements to explore two possible scenarios and investigate their nature. For particles reflecting solar radiation, clouds of CO2-ice or H2O-ice particles with an effective radius of 0.1 micrometres are favoured over dust. Alternatively, the plume could arise from auroral emission, of a brightness more than 1,000 times that of the Earth's aurora, over a region with a strong magnetic anomaly where aurorae have previously been detected. Importantly, both explanations defy our current understanding of Mars' upper atmosphere.

Inflammatory pseudo-tumours of the abdomen: plasma cell granulomas.

Pseudo-tumours of the plasma cell granuloma type are reported in two patients. One was retroperitoneal and the other intraabdominal. Most of the cases of plasma cell granulomas described in the literature have been in the lung (Brunn, 1939; Childress and Adie, 1950; Cotton, 1952; Umiker and Iverson, 1954; Lane, Krohn, Kolozai, and Whitehead, 1955; Liebow and Hubbell, 1956; Titus, Harrison, Clagett, Anderson, and Knaff, 1962; Mason, Keats, and Baker, 1963; Wentworth, Lynch, Fallis, Turner, Lowden, and Conen, 1968; Bahadori and Liebow, 1973). A retroperitoneal site has not to our knowledge been reported previously. The postinflammatory nature of such lesions and the significance of a previous history of abdominal surgery are emphasized. It is important to be aware of such benign lesions which may simulate malignant tumours so that unnecessary radical treatment can be avoided.

Prognostic features of thyroid cancer. A long-term followup of 68 cases.

Sixty-eight cases of thyroid cancer were followed for 10 to 38 years after diagnosis. A minimum followup period of 10 years was necessary because of the long natural history of low-grade thyroid carcinoma. The prognosis of the disease was evaluated with regard to several parameters: age, sex, histologic appearance of the tumor, extent of disease, and treatment. The best prognosis was found in women less than 40 years of age with papillary carcinoma in whom there was neither extrathyroid extension nor metastasis and who were treated by surgery alone. Extrathyroidal cancer in the neck treated by radical neck dissection had a 100% survival rate at 15 years postdiagnosis. The poorest prognosis was in male patients over 60 years of age with metastatic undifferentiated carcinoma.

Anaplastic seminoma.

Eight patients with the diagnosis of anaplastic seminoma of the testicle were treated during the megavoltage era from January 1959 to January 1976. Two patients with Stage I disease and one patient with Stage IV disease have died from their malignancy. By contrast, 57 patients with typical seminoma were treated during the same interval and with the same treatment methods. However, only two patients with typical seminoma have died. One of these patients had Stage II disease and one had Stage IV disease. There were no deaths among patients with Stage I typical seminoma. These results suggest that anaplastic seminoma has a poorer prognosis than typical seminoma even when the diseases are compared stage for stage. Implications for therapy are discussed.

Autopsy findings in carcinoma of the esophagus.

At autopsy of 82 cases of carcinoma of the esophagus over a period of 25 years metastatic tumor was found in 42 cases (51%) and residual tumor in the esophagus in 56 cases (86%). The most frequent site of metastases was in the lymph nodes, followed by liver, lung, and adrenal gland. Direct extension of the tumor to adjacent structures was established in 30 cases (36%), and the most frequent structure involved was the trachea. Five cases had a second primary and two cases a second separate lesion at another level of the esophagus.

Morphology and pathogenesis of desquamative interstitial pneumonitis.

Thirty human lung biopsy specimens have been diagnoses as desquamative interstitial pneumonitis. Six cases had intraalveolar lesions, believed to be early, while 20 had advanced disease characterised by intraalveolar cellular clumps, alveolar wall fibrosis, distortion, and loss of pulmonary parenchyma. Electron microscopy, high resolution light microscopy, and cytological examination have shown that the characteristic clumps in the alveolar air spaces are formed predominantly by enlarged and aggregated macrophages. Lymphocytes and eosinophils are also present in the intraalveolar clumps and in alveolar walls. Inflammation and immunological mechanisms are suggested as causes of the cellular clumping. Interstitial pneumonitis, alveolar wall fibrosis, changes in the alveolar epithelium, and loss of lung parenchyma are believed to be secondary events.