Sloths (Bradypus variegatus) as a polygastric mammal.

Fermentative herbivorous animals have peculiar conformations of the digestive system. It is known that B. variegatus obtained the capacity for evolutionary adaptation, due to their ecology and eating habits. However, despite the literature on feeding management for this species, there is a lack of published information regarding its gastric morphology, and such information would support a better understanding on the diet and digestion of these individuals. We found seven gastric compartments, which histologically revealed three distinct patterns: an aglandular keratinized fraction (mechanical stomach) and two glandular fractions, one a mucus secretor and the other one composed of acid secreting cells (chemical stomach). With these evidences we understand that these individuals have gastric resemblance to ruminants, with some inherent peculiarities of this species, including the transit of the bolus.

Epithelioid angiosarcoma arising in schwannoma of the kidney: report of the first case and review of the literature.

BACKGROUND: Schwannoma and angiosarcoma are infrequent pathologies that have been rarely reported in the kidney. Angiosarcoma is an uncommon malignant tumor presenting a recognizable vascular differentiation. It can develop in any site but the most common locations include the skin, soft tissues, breast, bone, liver, and spleen while renal localization has been very rarely reported in the literature. Schwannoma is a benign peripheral nerve sheath tumor composed of cells with the immunophenotype and ultrastructural features of differentiated Schwann cells. It has a wide anatomical distribution but the most frequent locations include subcutaneous tissues of the extremities and the head and neck region and the retroperitoneal and mediastinal soft tissues. The occurrence of an angiosarcoma in a pre-existing schwannoma is an extremely rare event with <20 cases reported in worldwide literature. In the present study, a renal case of angiosarcoma arising in schwannoma is presented with a detailed review of the pertinent literature. CASE PRESENTATION: A 56-year-old man was admitted with a few days history of lower back pain and hematuria. Abdominal ultrasound showed a mass inside the left renal medulla. Subsequent imaging investigations with computed tomography and magnetic resonance confirmed the presence of the lesion and showed a pulmonary metastasis. CONCLUSIONS: The final histopathological examination led to the diagnosis of epithelioid angiosarcoma arising in a schwannoma. The patient came to death a few months later due to a massive hemothorax. To the best of our knowledge, the present is the first case of an angiosarcoma arising in a schwannoma of the kidney.

Multiple cementoblastoma: a rare case report.

Benign cementoblastoma is a rare ectomesenchymal odontogenic tumor that originates from the root of the tooth and that is characterized by the formation of cementum-like tissue. A 60-year old man was referred to us complaining of pain in his right jaw. The patient underwent TC dental scan of the mandible, which highlighted the presence of three well-circumscribed, round, unilocular neoformations of radiopaque appearance with a radiotransparent edge, one of which was in close contact with the roots of the lower right second molar. Microscopic examination of the greater sample consisted, in its central portion, of dense mineralized acellular trabeculae of basophilic tissue cement-like, devoid of vessels, adhering to the root of the tooth, while peripherally was observed a zone of vascularized osteoid surrounded, occasionally, by a thin rim of cementoblasts mixed with fibrous tissue and inflammatory elements. This lesion was diagnosed as cementoblastoma. The second lesion appeared radiologically and histologically entirely identical to cementoblastoma, but it did not show the intimate association with the root of involved tooth. After a careful review of the literature, the diagnosis of residual cementoblastoma was made. The clinicopathologic features, treatment, and prognosis of this rare tumor are here discussed for the young dental practitioner.

Extraskeletal osteosarcoma: a very rare case report of primary tumor of the colon-rectum and review of the literature.

Extraskeletal osteosarcoma (ESOS) is a malignant mesenchymal tumor in which neoplastic cells produce bone osteoid in variable amounts. An 81-year-old woman presented with severe abdominal pain, tenesmus, constipation and rectal bleeding. The digital rectal exploration showed a large lesion of hard consistency, occupying the lumen, with the presence of splinters that "pierced" the endoscopist's glove. Endoscopic examination and CTscan revealed an ulcerative exophytic neoplasia of the lower rectum in which multiple calcified areas were found. The lesion showed no bone involvement. An abdominal perineal resection sec Miles was performed. The histological examination revealed a highly cellular mesenchymal lesion, with spindle and epithelioid cells with moderate nuclear pleomorphism. The calcified component consisted of widespread osteoid deposition. The immunohistochemical investigations of neoplastic cells showed strong positivity for vimentin and osteonectin. The definitive histological diagnosis of primary extraskeletal osteosarcoma arising from the colon-rectum was made. To our knowledge, only one previous case of colonic osteosarcoma was published in the literature in 2001, reported by Shimazu and other authors. The extreme rarity of the tumor at this location, also confirmed by morphological and immunohistochemical data, prompted us to present this case report and to review the literature.

Verrucous carcinoma of the foot with bone invasion: a case report.

Verrucous carcinoma of the foot often affects deep structures such as tendons, muscles, or bones. A 74-year-old man presented with a foot lesion that had been diagnosed as a skin infection 7 years earlier. He was treated with multiple excisions and superficial biopsies associated with antibiotic therapy without success. In our department he underwent an aggressive and accurate debridement with marginal excision harvesting multiple biopsies. Pathological evaluation of tissue at the time of operation confirmed the diagnosis of verrucous carcinoma of the foot. Therefore, the patient underwent an amputation below knee, and there were no postoperative complications; the patient was able to walk with the aid of a prosthesis with no signs of recurrence. The lesion follows a chronic course evolving from a discrete focal lesion to a large fungating deeply penetrating mass often compromised by local infection. The slow growth and confusing early-stage appearances can lead to delays in diagnosis of 8 to 15 years causing the extracutaneous involvement that requires a leg amputation. Many patients are initially treated with many topical medications without success, and most tumors have been treated as recalcitrant warts or corns for some time, whereas the basic approach is surgical.

Fibrous Variant of Hashimoto's Thyroiditis as a Diagnostic Pitfall in Thyroid Pathology.

Fibrous variant of Hashimoto's thyroiditis is a rare condition occurring in about 10% cases, mainly middle age people. It is characterized by an extensive fibrous proliferation without extension into the surrounding structures. A 55-year-old female was referred to our department for an unexplained onset of cervical discomfort. She presented a voluminous goiter of hard consistence, dyspnea and dysphagia. Given the compressive symptoms and the non-diagnostic result of the biopsy, a total thyroidectomy was performed. Microscopically the thyroid parenchyma was characterized by broad bands of fibrosis with severe atrophy of thyroid follicles and lymphocytic inflammatory infiltrate distributed within and around the lobules. In view of the morphological and immunohistochemical findings, a diagnosis of HTFV was made. The fibrosclerotic process is the key feature of several thyroid diseases so that the clinician and the pathologist have to consider that many diagnostic pitfalls can occur in this field. The differential diagnosis between HTFV and RD is sometimes arduous due to the partial clinical and morphological overlapping and to the poor efficacy of conventional cytology as well as pre-surgical biopsy. Considering these features, histological examination is mostly mandatory.

An apparently benign vulvar mass: possibly a rare malignancy.

BACKGROUND: Vulvar dermatofibrosarcoma is a rare fibrous tumor of intermediate grade malignancy, with a tendency for local recurrence, and rarely metastasizes. Management should be multidisciplinary. This is a report of an apparently benign vulvar mass with delayed diagnosis of vulvar dermatofibrosarcoma. CASE REPORT: A 42-year-old woman was referred to our hospital because of a vulvar tumor lasting 16 years, although several gynecological procedures and a total laparoscopic hysterectomy had been performed two years before. During this long period the lesion did not change morphological features and remained asymptomatic. Only a benign vulvar mass was diagnosed. Then, the swelling became evident showing erythematous skin with an aspect of "peau d'orange", leading the patient to consult a specialist. A firm vulvar swelling was observed in the anterior third of right labia majora continuing with about 3 cm of cord on top, quite movable above the underlying tissue but not on the overlying tissue. A wide excision was performed. The pathological examination showed positive margins. One month later an extensive deeper excision was performed. Histology confirmed a diagnosis of dermatofibrosarcoma. Immunohistochemistry was strongly positive for CD34. CONCLUSION: Vulvar lesions always require complete pathologic examination even in case of features of benign tumor to exclude a dermatofibrosarcoma. The role of the pathologist is essential to ensure negative microscopic margins and to avoid local recurrence.

The trypanothione system.

Trypanosomes and Leishmania, the causative agents of severe tropical diseases, employ 2-Cys-peroxiredoxins together with cysteine-homologues of glutathione peroxidases and ascorbate-dependent peroxidases for the detoxification of hydroperoxides. All three types of peroxidases gain their reducing equivalents from the parasite-specific dithiol trypanothione [bis(glutathionyl)spermidine]. Based on their primary structure and cellular localization, the trypanosomatid 2-Cys-peroxiredoxins are subdivided into two families that occur in the mitochondrion and cytosol of the parasites. In Trypanosoma brucei, the cytosolic 2-Cys-peroxiredoxin, as well as the glutathione peroxidase-type enzyme, is essential for cell viability. Despite overlapping substrate specificities and subcellular localizations, the two types of peroxidases can obviously not substitute for each other which suggests distinct cell-physiological roles.

The vasovagal Syncope and pacing (Synpace) trial: rationale and study design.

BACKGROUND: Though vasovagal syncope probably does not directly cause death, it is often associated with severe trauma and, when recurrent, significantly impairs the patient's quality of life. While drug therapy for vasovagal syncope is still controversial, recently two randomized studies revealed the efficacy of dual-chamber pacemaker implantation in decreasing recurrences in very symptomatic patients. However, since both studies were not placebo-controlled, the benefits observed might have been due to the placebo effect of the pacemaker. AIM OF THE STUDY: The aim of the vasovagal Syncope and pacing (Synpace) trial, a multicentre, prospective, randomized, double-blind, placebo-controlled trial, is to ascertain whether, in patients suffering from recurrent vasovagal syncope, the implantation of a dual-chamber pacemaker with rate drop response algorithm programmed to ON, will reduce syncope relapses compared with the implantation of a pacemaker programmed to OFF. Moreover, in order to evaluate the role of the haemodynamic response during tilt-induced syncope in identifying those patients who will benefit most from pacemaker implantation, enrolled patients will be divided into two groups on the basis of their haemodynamic behaviour during tilt-induced syncope: group 1, asystolic response (development of asystole >3 s), and group 2, mixed response (development of bradycardia <60 bpm, without asystole >3 s). The head-up tilt testing protocol will consist of 20 min at 60 degrees without drug potentiation, followed by 15 min at the same inclination after 400 microg of sublingual nitroglycerin. Results from the two groups will be analysed both separately and globally. The primary clinical endpoint of the study will be syncope. INCLUSION AND EXCLUSION CRITERIA: To be enrolled, patients will have to meet the following criteria: at least six syncopal episodes in the patient's lifetime; positive head-up tilt testing with asystolic or mixed response; at least one syncope recurrence following a positive head-up tilt test. The following constitute exclusion criteria: non-vasovagal syncope; other indications for pacing. SAMPLE SIZE: We hypothesize a risk of syncope recurrence of 70% after one year, and we estimate that--owing to the placebo effect alone--pacemaker will produce a 20% decrease in risk, which corresponds to a 50% risk of recurrence after one year, in those patients randomized to 'pacemaker OFF'. We calculate conservatively a risk decrease of 60% in patients with 'pacemaker ON'. This implies a 10% incidence of syncope recurrence after one year, vs 50% in patients with 'pacemaker OFF'. Fifty patients will need to be enrolled in the study: 25 patients for each group.

Intravascular physiologic evaluation of the left anterior small thoracotomy operation: a novel approach to left anterior descending artery revascularization.

BACKGROUND: Efficacy and long-term patency rate of the left internal mammary artery (LIMA) conduits for revascularization of the left anterior descending coronary artery (LAD) has been demonstrated, with improved results as compared to the saphenous vein graft operation. Novel approaches to LAD revascularization including the use of the left anterior small thoracotomy (LAST) operation with persistence of the intercostal arteries compared to the traditional LIMA operation have not been reported. This study evaluated flow characteristics of LAST operation. METHODS: Phasic blood flow velocity in the proximal and distal arterial conduit segments was measured in 30 patients by intravascular Doppler flow wire after surgical revascularization of the LAD: 15 patients were revascularized by conventional operation using the LIMA (Group A), and 15 patients were submitted to the LAST operation (Group B). All patients underwent coronary angiography and ventriculography at 116 +/- 111 days after operation. Only angiographically normal grafts with normal left ventricular wall motion and coronary arteries free from significant distal stenosis were included for coronary flow velocity and reserve measurements. RESULTS: The diastolic/systolic velocity ratio in the proximal portion of the internal mammary artery was similar in the two groups (Group A 0.8 +/- 0.2 vs Group B 0.7 +/- 0.3, p = NS). Distal diastolic/systolic velocity ratio in Group A (1.7 +/- 0.1) was higher than Group B (0.9 +/- 0.3, p < 0.001). There were no differences in basal average peak velocity or coronary flow reserve between the proximal and distal segments for either groups. CONCLUSIONS: Although proximal phasic coronary flow patterns between the two groups were similar, distal diastolic/systolic velocity ratio was higher in the LIMA than in the LAST. This difference may be related to the persistence of the intercostal artery in the LAST operation. These data confirm the continued patency and similar functional flow patterns compared to the conventional LIMA operation, supporting further investigation and application of this novel approach to LAD revascularization.

Persistence of mammary artery branches and blood supply to the left anterior descending artery.

BACKGROUND: Partial harvesting of the left internal mammary artery (LIMA) is a widespread technique used during minimally invasive coronary operations performed through a left anterior small thoracotomy. The influence of persisting LIMA branches was investigated to evaluate their effect on the blood flow of the left anterior descending artery. METHODS: Thirty patients, 15 with totally (group A) and 15 with partially (group B) harvested LIMAs, were evaluated. All the patients underwent postoperative angiography, during which a flow map of the LIMA was performed. The average peak velocity and the diastolic-to-systolic peak velocity ratio were recorded. The LIMA graft flow pattern was recorded in the proximal and distal thirds of the artery. Intramammary adenosine (12 to 14 microg) was injected and the average peak velocities before and after injection were calculated. RESULTS: The average peak velocity was similar in both groups in the proximal and distal thirds of the LIMA (25 +/- 7 and 26 +/- 5 cm/sec, respectively, in group A versus 27 +/- 5 and 25 +/- 5 cm/sec, respectively in group B; p = NS). The diastolic-to-systolic peak velocity ratio was similar proximally (0.78 +/- 0.3 in group A versus 0.69 +/- 0.3 cm/s in group B; p = NS), but not distally (1.72 +/- 0.1 in group A versus 0.97 +/- 0.3 in group B; p < 0.0005). The LIMA graft flow reserve was similar both proximally and distally (2.6 +/- 0.6 and 2.5 +/- 0.3 cm/s, respectively, in group A versus 2.6 +/- 0.5 and 2.6 +/- 0.3 cm/s, respectively, in group B; p = NS). CONCLUSIONS: The persistence of LIMA branches does not influence the blood flow of the left anterior descending artery after acute adenosine-induced myocardial hyperemia. If a left anterior small thoracotomy is used in left anterior descending artery direct revascularization, complete LIMA harvesting is not mandatory and depends on the personal preference of the surgeon.

[Idiopathic restrictive cardiomyopathy. Description of 4 cases]. / Cardiomiopatia restrittiva idiopatica. Descrizione di 4 casi.

The clinical and instrumental characteristics of four patients suffering from idiopathic restrictive cardiomyopathy are analysed. Patients were diagnosed following hemodynamic and histological tests. The major clinical symptom was cardiac decompensation and/or hyperkinetic or hypokinetic (3rd degree BAV) supraventricular arrhythmia (atrial fibrillation). Electrocardiographic and radiological alterations were not specific. The most typical echocardiographic symptom was the association of: biatrial dilation, dilation and hypertrophy of the right ventricle, normal left ventricular size, normal fractional shortening of the left ventricle. Septal hypertrophy was also observed in one case. Abundant pericardial effusion was present in all cases. When performed, echo-Doppler showed a relatively typical shortened deceleration time through the A-V valve. Catheterism revealed increased ventricular telediastolic pressures and a bi-plateau morphology of the ventricular pressure curve. Heart index was depressed in one patient and the ejection fraction was reduced in one case. Histological tests revealed interstitial fibrosis, cellular hypertrophy and, in one patient, myocardial amyloidosis. One patient underwent a heart transplant, two patients died while waiting for a transplant, one patient is still alive 13 years after the start of 3rd class symptoms.