Pulmonary Langerhans Cell Histiocytosis and Diabetes Insipidus in a Young Smoker.

Langerhans cell histiocytosis is characterized by the abnormal nodular proliferation of histiocytes in various organ systems. Pulmonary involvement seen in young adults is nearly always seen in the context of past or current cigarette smoking. Although it tends to be a single-system disease, extrapulmonary manifestations involving the skin, bone, and hypothalamic-pituitary-axis are possible. High resolution CT (HRCT) of the thorax findings includes centrilobular nodules and cysts that are bizarre in shape, variable in size, and thin-walled. Often the diagnosis can be made based on the appropriate clinical presentation and typical imaging findings. Treatment includes smoking cessation and the potential use of glucocorticoids or cytotoxic agents depending on the severity of disease and multisystem involvement.

[Apoplectic macroadenomas: the outcome of the residual pituitary gland]. / Macroadénomes apoplectiques: le devenir de l'hypophyse résiduelle.

BACKGROUND AND PURPOSE: The purpose of this retrospective study was to assess the MRI aspects and the function of the residual pituitary gland (RPG) after surgical decompression of an apoplectic pituitary macroadenoma, and to attempt to answer the question of whether an intra-adenomatous apoplexy necessarily leads to hypophyseal apoplexy. METHODS: Between 1992 and 2008, 150 pituitary macroadenomas were surgically treated via the trans-sphenoidal approach, 19 of which presented an apoplectic feature (13%). They were subdivided into three groups: pure hemorrhage, hemorrhagic infarction, and ischemic infarction. The imaging was studied after surgery to identify the RPG and establish a correlation with the endocrine status. RESULTS: After surgery five of 19 patients had normal adenohypophyseal function (27%), eight (42%) had panhypopituitarism, and six (31%) complete or partial corticotropic hypopituitarism. The RPG was identified on MRI in 13 patients (69%), four of them (31%) with normal adenohypophyseal function. The RPG was clearly identified intraoperatively in nine patients (47%), four of whom (44%) had normal adenohypophyseal function. One patient presented preoperative diabetes insipidus, which disappeared immediately after surgery, and two other patients developed postoperative diabetes insipidus: in one patient it quickly declined and in the other one it persisted, requiring replacement. According to the radiological classification of Hardy and Vezina modified by the Mohr (Mohr et Hardy, 1982) grade, the patients were subdivided up as follows: one grade II-0, four grade II-A, 11 grade II-B, two grade C, and one grade IV-B+D. CONCLUSION: The repercussions of adenomatous apoplexy on the RPG is significant: only 27% of the patients retained normal pituitary function. Furthermore, although the RPG was identified on the MRI in more than two-thirds of the cases, more than half had adenohypophyseal failure: therefore, the visualization of a RPG does not mean that its functions are preserved. The involvement of the neurohypophysis is much rarer: one patient of 19 (5%). The implications of the ischemic or compressive damage on the normal pituitary gland are discussed.

Pulsation-pressure relationship in experimental aneurysms: observation of aneurysmal hysteresis.

In this study the pulsation-pressure relationship in an experimental model of aneurysms was analyzed. In addition, we have examined pulsatility of the aneurysmal wall reinforced by Guglielmi Detachable Coils (GDC). Bifurcation (BAn), aneurysms (LAn) and bilobar (BiA) aneurysms were produced in 15 mongrel dogs. The aneurysmal dome was constructed from a segment of the external jugular vein which was sutured to the window performed on the apex of bifurcation of the ECA and lingual artery (BAn) or on the ECA (LAn). One set of the GDC (diameter 5 mm, length 20 cm) were inserted into the aneurysm. Intra-aneurysmal pressure, aneurysmal pulsation, ECG and femoral artery pressure were recorded. Results showed that an experimental aneurysm pulsates in synchrony with the intra-aneurysmal pressure and aneurysmal pulsation is proportional to the aneurysmal size. Pulsation profile also depends on the aneurysmal type (BAn, LAn, BiA). The looped pressure-pulsation curve indicates that aneurysms exhibit property of hysteresis. For the same pressure the aneurysm is smaller during the ascending (systolic) portion of the blood pressure wave. Insertion of catheter into the aneurysm and subsequent release of the GDC did not elicit any measurable changes of the intra-aneurysmal pressure. Aneurysm reinforced by GDC showed smaller pulsation and the hysteresis was reduced as well. It was concluded that aneurysmal hysteresis could be an important factor resulting in degeneration of aneurysmal wall since it is known that hysteresis accelerates degeneration of all fibrous elements, predominantly of elastic fibers. GDC seems to buffer the intra-aneurysmal hemodynamic forces and hence they might have a stabilizing effect on the aneurysmal wall.

[Diabetes insipidus caused by metastasis to the hypothalamo-hypophyseal axis. Apropos of 4 cases]. / Diabète insipide par métastase de l'axe hypothalamo-hypophysaire. A propos de 4 cas.

This study concerns the cases of 4 patients with polyuria and polydipsia syndrome as part of a known evolutive neoplasia. MRI demonstrated an intra- and supersellar tumoral process developed from the pituitary stalk and the posterior pituitary lobe suggesting metastasis.