A rare case of necrotic thymoma.

The Authors report the case of a patient who underwent resection of a huge anterior mediastinal mass, revealing to be a necrotic thymoma. The patient had been previously submitted to surgical biopsies of the mass yielding non-diagnostic results due to extensive necrosis. A sternotomy was then performed to resect the mediastinal mass originating from the thymus, en-bloc with the mediastinal fat and the apparently infiltrated lung. Histopathology showed a possible cyst/thymoma in massive necrosis, not further definable; revision by a specialized experienced pathologist (J. Rosai) confirmed total mass necrosis and no lung infiltration, thus orientating diagnosis towards a necrotic thymoma and excluding a lymphoblastic lymphoma, with similar histopathological features but more frequent in children or characterized by neoplastic infiltration of surrounding lung. Total body computed tomography (CT) scan and fluorodeoxyglucose positron emission tomography (18F-FDG-PET)/CT, show neither local recurrence, nor distant metastases two years after surgery. In case of anterior mediastinal mass with difficult histopathological diagnosis due to massive necrosis, the hypothesis of a necrotic thymoma should be considered. After radical removal prognosis is generally favourable and no adjuvant treatment is required.

[Autofluorescence bronchoscopy in early diagnosis of pulmonary carcinoma]. / Broncoscopia ad autofluorescenza nell'anticipazione diagnostica del carcinoma polmonare.

AIM: Autofluorescence bronchoscopy (AFB) has been proposed to widen traditional white light bronchoscopy (WLB) possibilities of early diagnosis of neoplastic and preneoplastic lesions of the tracheo-bronchial mucosa in high risk groups. The authors report their study on AFB with the aim of establishing its role in the early diagnosis of bronchogenic carcinoma and its positive predictive value (PPV) compared and associated to WLB. METHODS: From May 2002 to May 2004 we performed WLB and AFB in 213 patients (177 males, 36 females), mean age 63.7 years (range 18-84 years), who were divided into 2 main groups (group A: patients at risk for bronchogenic carcinoma, n=82; group B: patients to be operated on for bronchogenic carcinoma, n=131). In total, 237 WLB-AFB were performed (101 in group A, 136 in group B) and 77 biopsies for pathological examination. RESULTS: The 2 tools (WLB and AFB) were concordant in 156 (66%) and discordant in 81 (34%) cases. Considering the biopsies performed, we obtained a PPV of 26% for lesions visible with WLB, of 40% for those visible with AFB, of 38% for those visible with the association of both. In group A, in 56 patients of the follow-up subgroup, we found 2 dysplastic areas and 1 carcinoma in situ. In group B there was a discordant extension of the pathologic area visible with WLB and with AFB in 30 cases which was positive in 18 of them at histological examination. CONCLUSIONS: In our experience, AFB has revealed to be a valid tool for both early diagnosis of neoplastic recurrences or a second primary lung neoplasia in patients in follow-up after resection and preoperative evaluation of resection margins in patients candidate to surgery. More studies are needed to widen its indications in the early diagnosis in high risk groups, to improve its potentialities and optimize its learning curve in order to establish the procedural guide lines.

Functional evaluation of 5-hydroxytryptamine receptor activity in rat resistance vessels.

1. To characterize 5-hydroxytryptamine (5-HT) receptors in rat perfused mesenteric vascular bed (MVB), the effect of 5-HT and related compounds was investigated by functional assay. 2. In quiescent preparations, 5-HT elicited a concentration-dependent conctractile response. After addition of ketanserin, a 5-HT2 receptor antagonist, EC50 values were significantly higher than in controls. 3. In noradrenaline (NA)-precontracted preparations, under continuous infusion of ketanserin, 5-HT, 5-carboxamidotryptamine (5-CT) and sumatriptan produced relaxation. Their rank order of relaxant potency and maximum effect were sumatriptan > 5-HT > 5-CT. Methysergide (1 microM) and spiperone (20-100 nM) caused a rightward shift of the relaxation curve to sumatriptan. These data suggest that vasodilatation in rat MVB is mediated by an 'atypical' subtype of 5-HT1-like receptor, which reveals a pharmacological profile similar to that of the 5-HT1D receptor. The involvement of both 5-HT3 and 5-HT4 receptors can be ruled out, since tropisetron (up to 10 microM) was not able to antagonize the relaxant effect by sumatriptan. 4. Under granisetron infusion (3 microM), the contractile response evoked by perivascular nervous stimulation, but not exogenous NA contraction, was significantly reduced (P < 0.001). These data demonstrate the presence of 5-HT3 receptors in peripheral neurones, modulating neurotransmitters release.

Cholinergic stimulation and nonadrenergic, noncholinergic relaxation of human colonic circular muscle in idiopathic chronic constipation.

The aim of our study was to further investigate the pathophysiological mechanism underlying idiopathic chronic constipation (ICC), a disorder of colonic motility. A possible alteration of excitatory and inhibitory neurotransmission and also the role of inhibitory neurotransmitters such as nitric oxide (NO), 5'-adenosine triphosphate (ATP), and vasoactive intestinal peptide (VIP) has been evaluated on preparations of distal colon from patients with or without ICC. The isometric tension was recorded from isolated circular muscle strips of both experimental groups during pharmacological and electrical field stimulation (EFS). The contractile response obtained by acetylcholine (ACh 20 microM), EFS (20 Hz, 20 V, 1 msec, pulse trains lasting 1 min) and substance P (SP 1 microM) was significantly lower in ICC than in control preparations. The effect of inhibitory nonadrenergic, noncholinergic innervation was evaluated using EFS at low frequencies (0.5-8 Hz), after cholinergic and sympathetic blockade with atropine (3 microM) and guanethidine (3 microM). The maximum relaxation value expressed as percentage of inhibition of SP-induced contraction was significantly higher in ICC than in control preparations (87+/-2.4 and 67+/-6.3, respectively; P<0.05). Experiments with substances that antagonize or reduce the effect of putative inhibitory mediators (VIP 6-28, apamin and N(G)-nitro-L-arginine) suggest that an alteration in NO and ATP release is present in ICC preparations. In particular at a higher inhibitory frequency NO-mediated relaxation is enhanced in ICC vs control, supporting the hypothesis that excessive NO production may be involved in pathophysiological mechanism of constipation.