Intravenous lipoma and pulmonary sarcoidosis treated with prednisone.

Corticosteroid-induced lipomatosis is not a rare condition, but lipoma in the central veins has scarcely been described. According to the databases consulted, this is the first report of a lipoma within the central veins coexistent with long-term use of corticosteroid. It involved a 47-year-old male under treatment for pulmonary sarcoidosis with prednisone. Computerized tomography of the thorax was performed and incidentally the images showed a mass within the central veins with the characteristics of lipoma. He was asymptomatic and refused surgical procedures. The intraluminal lipoma originated in the right brachiocephalic and subclavian veins. Control tomography showed a slow development of this lipoma, without obstructive effects or malignant features. Oral prednisone was changed for methotrexate. The patient is asymptomatic and under longstanding out-patient surveillance. Corticosteroid treatments for sarcoidosis can play a role in the development of intravascular lipoma, but this association is not well defined. Case reports could contribute to clarifying whether this relationship is causal or merely casual.

Evidence of a suffocation alarm system within the periaqueductal gray matter of the rat.

Dyspnea, hunger for air, and urge to flee are the cardinal symptoms of panic attacks. Patients also show baseline respiratory abnormalities and a higher rate of comorbid and antecedent respiratory diseases. Panic attacks are also precipitated by infusion of sodium lactate and inhalation of 5% CO2 in predisposed patients but not in healthy volunteers or patients without panic disorder. Accordingly, Klein [Klein (1993) Arch Gen Psychiatry 50:306-317] suggested that clinical panic is the misfiring of an as-yet-unidentified suffocation alarm system. In rats, selective anoxia of chemoreceptor cells by potassium cyanide (KCN) and electrical and chemical stimulations of periaqueductal gray matter (PAG) produce defensive behaviors, which resemble panic attacks. Thus, here we examined the effects of single or combined administrations of CO2 (8% and 13%) and KCN (10-80 µg, i.v.) on spontaneous and PAG-evoked behaviors of rats either intact or bearing electrolytic lesions of PAG. Exposure to CO2 alone reduced grooming while increased exophthalmus, suggesting an arousal response to non-visual cues of environment. Unexpectedly, however, CO2 attenuated PAG-evoked immobility, trotting, and galloping while facilitated defecation and micturition. Conversely, KCN produced all defensive behaviors of the rat and facilitated PAG-evoked trotting, galloping, and defecation. There were also facilitatory trends in PAG-evoked exophthalmus, immobility, and jumping. Moreover, whereas the KCN-evoked defensive behaviors were attenuated or even suppressed by discrete lesions of PAG, they were markedly facilitated by CO2. Authors suggest that the PAG harbors an anoxia-sensitive suffocation alarm system which activation precipitates panic attacks and potentiates the subject responses to hypercapnia.