Predictors of malignancy in high-risk indeterminate (TIR3B) cytopathology thyroid nodules.

PURPOSE: The classification of indeterminate cytopathology at thyroid fine-needle-aspiration (FNA) has been updated to reduce the number of unnecessary surgery; the 2014 Italian classification introduced the low-risk (TIR3A) and high-risk (TIR3B) subcategories. Aim of this study was to identify the ultrasonographic (US), clinical and cytological predictors of malignancy among TIR3B nodules from a single institution. METHODS: A prospective observational study including 1844 patients who underwent thyroid FNA from June 2014 to January 2019. Ultrasonographic, clinical and cytological features were recorded. All TIR3B diagnoses were referred to surgery. According to final histology, patients were divided into thyroid cancer (TC) or benign nodules. Chi-square test, or Fisher exact test when appropriate, were used to compare groups and logistic regression analyses were used to determine independent predictors of malignancy. RESULTS: Of 1844 FNAs, 96 (5.2%) were TIR3B. Histology report was available in 65. Among them, 25 (38.5%) were TC. Predictors of TC were nodule size < 20 mm [Odds Ratio (OR) = 5.88, 95% CI 1.91-18.11, p = 0.002], absence or weak intralesional flow [OR = 0.3, 95% CI 0.09-0.77, p = 0.015], microcalcifications [OR = 6.5, 95% CI 1.90-21.93, p = 0.003] at US; nuclear inclusions [OR = 25.3, 95% CI 1.34-476.07, p = 0.031] and chromatin clearing [OR = 3.7, 95% CI 1.27-10.99, p = 0.017] at cytopathology. Patients aged < 55 years had a significantly higher risk of TC [OR = 9.7, 95% CI 2.79-34.07, p < 0.001]. In multivariate analysis, age < 55 and nodule size < 20 mm resulted as independent risk factors. CONCLUSIONS: Patients < 55 years receiving a diagnosis TIR3B on nodules < 20 mm, with microcalcifications, showing specific nuclear atypia at cytopathology are more likely to have TC. Combining US, cytological and clinical features could help determining which patients with a TIR3B diagnosis should be referred to surgery.

What's new in mesothelioma.

Malignant pleural mesothelioma is a neoplasm characterized by a very poor prognosis and medico-legal implications. Diagnosis, prognosis and therapy are often challenging and include several issues. Cytological diagnosis is frequently the first step of the diagnostic process, and although its sensitivity may be somewhat lower, diagnostic criteria should be taken into account. When effusion cytology is inconclusive for the diagnosis, tissue biopsies should be taken. Even if the morphologic criteria for deciding whether a mesothelial proliferation is a benign or a malignant process have been defined, the separation of benign from malignant mesothelial proliferation is often a difficult problem for the pathologist, particularly on small biopsies. Thirdly, when the diagnosis is made, despite many efforts have been made to identify possible new biomarkers for early diagnosis, prognostic stratification and also predictive tools should be defined. Nowadays, the main prognostic parameter is still represented by the histological subtype, having the epithelioid MPM a better outcome than the sarcomatoid or biphasic MPM. A nuclear grading system have been also proposed to stratify patient outcome. Reliable predictive biomarkers are still lacking in MPM and a personalized therapeutic concept is eagerly needed. Mesothelioma occurs mostly as sporadic cancer and the main risk factor is asbestos exposure, but it also occurs among blood relatives suggesting possible increased genetic susceptibility besides shared exposures. Recently the study of genetic predisposition syndrome raised new aspect in the occurrence of mesothelioma cases.This review summarize these most important issues.

Evaluation of the Italian cytological subclassification of thyroid indeterminate nodules into TIR-3A and TIR-3B: a retrospective study of 290 cases with histological correlation from a single institution.

PURPOSE: The Italian consensus to classify thyroid cytology has provided a standardized reporting scheme, including the subdivision of indeterminate for malignancy TIR-3 category into TIR-3A (low-risk) and TIR-3B (high-risk). We aimed to present our experience on this subclassification by evaluating risks of malignancy and the validity in sorting nodules with dissimilar risks. Another aim was to compare our performance against the Bethesda system. METHODS: Fine-needle aspirates of 290 TIR-3 that underwent thyroid surgery at our hospital (2008-2013) were reviewed and divided into TIR-3A or TIR-3B, and AUS/FLUS or FN/SFN. Cytological diagnoses were then correlated to histology. Results were evaluated using univariate analysis. RESULTS: The subclassification into TIR-3A and TIR-3B differentiated hyperplastic nodules (p = 0.000) but not adenomas (p = 0.090). Rates of malignancy were significantly different between TIR-3A (10.2%) and TIR-3B (43.8%); TIR-3B malignancies were often papillary carcinomas (83%). TIR-3A/TIR-3B accounted for high sensitivity (84.5%; CI 79.7-88.4%), accuracy (64.1%; CI 58.6-69.6%) and NPV (89.8%; CI 85.6-93.0%) as opposed to modest specificity (55.8%; CI 49.9-61.6%) and PPV (43.8%; CI 38.1-49.8%). The rate of malignancy in AUS-FLUS was higher than in TIR-3A (p = 0.007), whereas it was not different between FN/SFN and TIR-3B (p = 0.337). Sensitivity of the Bethesda system was significantly lower respect to the Italian system. CONCLUSIONS: The study supports the Italian consensus showing a different risk of malignancy for TIR-3A as compared to TIR-3B. TIR-3A/TIR-3B subclassification is valid to sort out benign nodules (high NPV) and malignancies (high sensitivity) but not adenomas (modest specificity, low PPV). In our experience, sensitivity is the main difference between Italian and Bethesda systems.

CDKN2A and BAP1 germline mutations predispose to melanoma and mesothelioma.

BAP1 germline mutations predispose to a cancer predisposition syndrome that includes mesothelioma, cutaneous melanoma, uveal melanoma and other cancers. This co-occurrence suggests that these tumors share a common carcinogenic pathway. To evaluate this hypothesis, we studied 40 Italian families with mesothelioma and/or melanoma. The probands were sequenced for BAP1 and for the most common melanoma predisposition genes (i.e. CDKN2A, CDK4, TERT, MITF and POT1) to investigate if these genes may also confer susceptibility to mesothelioma. In two out of six families with both mesothelioma and melanoma we identified either a germline nonsense mutation (c.1153C > T, p.Arg385*) in BAP1 or a recurrent pathogenic germline mutation (c.301G > T, p.Gly101Trp) in CDKN2A. Our study suggests that CDKN2A, in addition to BAP1, could be involved in the melanoma and mesothelioma susceptibility, leading to the rare familial cancer syndromes. It also suggests that these tumors share key steps that drive carcinogenesis and that other genes may be involved in inherited predisposition to malignant mesothelioma and melanoma.

Zenker diverticulum in the right side of the neck resembling a thyroid mass at ultrasound.

Zenker’s diverticulum represents the most common form of pharyngo-oesophageal diverticula usually occurring on the left side of the neck. Due to its anatomical proximity to the thyroid, it can mimic a thyroid mass. Here we describe the case of an asymptomatic 49-year-old man referred to the Thyroid Clinic of the Policlinico Umberto I Hospital-“Sapienza” University of Rome for thyroid sonography due to a family history of autoimmune thyroid disease. The patient’s thyroid blood tests did not reveal any abnormalities. The sonographic examination showed a dishomogeneus and hypoechoic thyroid gland. In addition, in the third middle of the right lobe, a mass (with a diameter greater than 26 mm), with heterogeneous internal echogenicity, hypoechoic margins and internal hyperechoic spots was recorded, with no appreciable flow at the Doppler evaluation. The TI-RADS score was 4c. Hence, the patient underwent ultrasound-guided fine-needle aspiration cytology that revealed the presence of squamous cells without cytological atypia, erythrocytes, muscular and vegetable fibres, colonies of bacteria in the absence of inflammatory infiltrate. This was consistent with the diagnostic hypothesis of oesophagus diverticulum, which was confirmed by means of a barium-swallow oesophagography. This case report underlines the possibility that a suspicious thyroid mass may result from a Zenker’s diverticulum, even if located on the right side, especially if the lesion has a heterogeneous echo-texture, a hypoechoic rim and internal hyperechoic spots.

PAPILLARY THYROID CANCER IS CHARACTERIZED BY ALTERED EXPRESSION OF GENES INVOLVED IN THE SUMOYLATION PROCESS.

Small Ubiquitin–like MOdifier (SUMO) proteins are small protein modifiers capable of regulating cellular localization and function of target proteins. Over the last few years, a relevant role has been demonstrated for sumoylation in the modulation of important cellular processes, including gene transcription, DNA repair, cell-cycle regulation and apoptosis. Components of the sumoylation machinery have been found deregulated in different human cancers, and are thought to significantly affect cancer cell progression. In the present study we sought to analyze the expression of all the components of the sumoylation machinery in a case study comprising 77 papillary thyroid cancers (PTC) and normal matched tissues. In particular, we evaluated the expression of the SENP1 to SENP8 (SENtrin-specific proteases), SAE1 (SUMO1 activating enzyme subunit 1), UBA2 (UBiquitin-like modifier activating enzyme 2), UBC9 (UBiquitin conjugating enzyme 9), RanBP2 (RAN binding protein 2), MSMCE2 (Non- SMC element 2), CBX4 (ChromoBoX homolog 4), PIAS1 to PIAS4 (protein inhibitor of activated STAT), ZMIZ1 (zinc finger, MIZ-type containing 1) and ZMIZ2 (Zinc finger, MIZ-type containing 2) by means of quantitative RT-PCR. In most of the PTC examined we observed a significant alteration in the mRNAs of SENP8, ZMIZ1, SAE1, PIAS1 and PIAS2. These tended to be reduced in about 50 to 66% of cases, and unchanged or increased in the remaining ones. Univariate and Kaplan-Mayer analyses documented the lack of association between the expression of the above 5 genes and clinicopathological parameters. Only SAE1 was significantly higher in female PTC tissues, in respect to male PTC tissues (p=0.021), and SENP8 was significantly lower in TNM stages III-V, with respect to stages I-II (p=0.047). In conclusion, we demonstrated that the expression of SENP8, SAE1, PIAS1, PIAS2 and ZMIZ1 is deregulated in the majority of PTC tissues, likely contributing to the PTC phenotype. However, differently from other human cancers, their mRNA level does not represent a prognostic biomarker in PTC patients.

Guidelines for the Cytopathologic Diagnosis of Epithelioid and Mixed-Type Malignant Mesothelioma: a secondary publication.

OBJECTIVE: To provide practical guidelines for the cytopathologic diagnosis of malignant mesothelioma. DATA SOURCES: Cytopathologists with an interest in the field involved in the International Mesothelioma Interest Group (IMIG) and the International Academy of Cytology (IAC) contributed to this update. Reference material includes peer-reviewed publications and textbooks. RATIONALE: This article is the result of discussions during and after the IMIG 2012 conference in Boston, followed by thorough discussions during the 2013 IAC meeting in Paris. Additional contributions have been obtained from cytopathologists and scientists who could not attend these meetings, with final discussions and input during the IMIG 2014 conference in Cape Town.

Descriptive epidemiology of Kaposi sarcoma in Europe. Report from the RARECARE project.

Kaposi sarcoma (KS) is a virus-related malignancy which most frequently arises in skin, though visceral sites can also be involved. Infection with Kaposi sarcoma herpes virus (KSHV or HHV-8) is required for development of KS. Nowadays, most cases worldwide occur in persons who are immunosuppressed, usually because of HIV infection or as a result of therapy to combat rejection of a transplanted organ, but classic Kaposi sarcoma is predominantly a disease of the elderly without apparent immunosuppression. We analyzed 2667 KS incident cases diagnosed during 1995-2002 and registered by 75 population-based European cancer registries contributing to the RARECARE project. Total crude and age-standardized incidence rate was 0.3 per 100,000 per year with an estimated 1642 new cases per year in the EU27 countries. Age-standardized incidence rate was 0.8 per 100,000 in Southern Europe but below 0.3 per 100,000 in all other regions. The elevated rate in southern Europe was attributable to a combination of classic Kaposi sarcoma in some Mediterranean countries and the relatively high incidence of AIDS in several countries. Five-year relative survival for 2000-2002 by the period method was 75%. More than 10,000 persons were estimated to be alive in Europe at the beginning of 2008 with a past diagnosis of KS. The aetiological link with suppressed immunity means that many people alive following diagnosis of KS suffer comorbidity from a pre-existing condition. While KS is a rare cancer, it has a relatively good prognosis and so the number of people affected by it is quite large. Thus it provides a notable example of the importance of networking in diagnosis, therapy and research for rare cancers.

Surgical strategies in patients with medullary thyroid carcinoma.

OBJECTIVES: Aim of the study was to identify, in 59 operated patients affected by medullary thyroid carcinoma (MTC), the recurrence rate, survival, mortality and incidences of surgically derived hypoparathyroidism and recurrent laryngeal nerve injury (RLNI). MATERIALS AND METHODS: Based on pre-surgical diagnosis of the 59 patients included in the study, 35 underwent total thyroidectomy with central neck dissection (Group A), 14 total thyroidectomy, central neck dissection and monolateral functional neck dissection (Group B) and 10 total thyroidectomy central neck dissection, bilateral functional neck dissection (Group C). Overall survival, recurrences, incidence of hypoparathyroidism and RLNI were evaluated. RESULTS: The survival and recurrences were not statistically different among the three Groups. In Group B there was major probability of re-operation (p=0.042). The mortality rate was clearly major in Group C (p=0.003) due to the stage of pathology. Group C showed a high number of hypoparatiroidism compared to Group B, and B compared to A. In Group A there was only one unexpected RLNI; in 5 cases, 3 in Group B and 2 in Group C, there were a necessity laringeal section due to nerve tumor involvement. CONCLUSIONS: From our data it appears clearly that disease outcome following the different surgical approaches is mainly determinated by the stage of the disease at diagnosis. However, the finding that patients in Group A and B showed a high rate of local-regional recurrences may suggest that homolateral lymphadenectomy in Group A patients and bilateral lymphadenectomy in Group B patients should be always performed.

Cytologic re-evaluation of negative effusions from patients with malignant mesothelioma.

BACKGROUND: Cytology is a controversial means of diagnosing malignant mesothelioma due to the high rates of negative samples. The aim of the present study was to review effusions originally reported as "negative" in patients with histologically-proven mesothelioma to evaluate possible pitfalls. METHODS: We reviewed the cytologic slides of 25 specimens that refer to 15 epithelioid, 5 biphasic, 4 sarcomatoid and 1 well-differentiated papillary mesotheliomas. For comparison, we also reviewed 23 specimens from non-neoplastic conditions. For each effusion, we evaluated the background and calculated a score considering the following items: amount of mesothelial cells, architectural pattern and atypical features, and a revised diagnosis was rendered. RESULTS: More than half of the effusions initially called "negative" (but mesothelioma by histology) were considered atypical/ suspicious (false-negative diagnosis); the remaining cases were true-negative or inadequate. Almost all effusions initially called "negative" (but non-neoplastic by histology) were considered negative. The only item that seems to discriminate between the two groups is atypia of mesothelial cells. CONCLUSIONS: The present study has highlighted the following pitfalls: (i) to report effusions devoid of mesothelial cells as negative that instead should be reported as inadequate/non-diagnostic; (ii) to underestimate low cellular effusions containing atypical mesothelial cells or high cellular effusions containing bland mesothelial cells with a morular pattern; (iii) to consider that an inflammatory background may obscure a scant number of mesothelial cells. A categorized system (inadequate (M1), negative (M2), atypical (M3) and suspicious (M4)) for reporting effusion cytology may be of help in the diagnostic work-up of patients with effusions suspicious for mesothelioma.

Distribution of 'promoter' sandflies associated with incidence of classic Kaposi's sarcoma.

The patchy geographical distributions of classic Kaposi's sarcoma (KS) and human herpesvirus type 8 (HHV-8), better known as Kaposi's sarcoma-associated herpesvirus (KSHV) remain unexplained. It has been proposed that certain species of bloodsucking insects ('promoter arthropods') promote the reactivation of HHV-8/KSHV and facilitate both HHV-8/KSHV transmission and KS development. This hypothesis was tested by sampling the presence and density of human-biting Diptera with CDC light traps in two areas of Sardinia with contrasting incidence rates of classic KS. In total, 11,030 specimens (99.9% sandflies and 0.1% mosquitoes) belonging to 10 species were collected from 40 rural sites. Five of these species are considered to be possible promoter arthropods because of the irritation their bites cause: Phlebotomus perniciosus Newstead; Phlebotomus perfiliewi Parrot (Diptera: Psychodidae); Aedes berlandi Seguy; Culiseta annulata (Schrank) and Culex theileri Theobald (Diptera: Culicidae). Five species are probable 'non-promoters' because their bites are not particularly irritating: Culiseta longiareolata (Macquart); Culex pipiens s.l.; Anopheles algeriensis Theobald; Anopheles maculipennis s.l., and Anopheles plumbeus Stephens. A significant correlation was found between the geographical distribution of promoter arthropods and incidence rates of KS (Spearman's r = 0.59,P < 0.01). Promoter arthropods were more likely to be caught in areas with cutaneous leishmaniasis and a past high prevalence of malaria, and in areas of limestone, acid volcanic soil and cereal cultivation. The study supports the association between promoter arthropods and classic KS, which may explain the geographic variability of KS and HHV-8/KSHV, and highlights the links with a number of variables previously associated with the incidence of KS.

Cause-specific mortality in classic Kaposi's sarcoma: a population-based study in Italy (1995-2002).

BACKGROUND: Little information is available on the causes of death among persons with classic Kaposi's sarcoma (CKS). METHODS: We conducted a population-based study in Italy to identify deceased persons with CKS and the underlying causes of death among them, by reviewing multiple-causes-of-death records. Standardised mortality ratios (SMRs) and 95% confidence intervals were calculated to compare the distribution of causes to that among the same-age general population of deceased persons. The geographical distribution was also evaluated. RESULTS: Of the 946 deaths among persons with CKS, 65.9% were attributable to non-neoplastic conditions and 21.9% to malignancies. For 12.2%, no lethal pathology was identified and CKS was considered as the underlying cause. In 90% of these cases, there was visceral/nodal involvement, therapy-related complications, or neoplastic cachexia. Among persons with CKS who died of other causes, an excess for lymphoid malignancies emerged (SMR=4.40) (chronic lymphocytic leukaemia (11.03), non-Hodgkin's lymphoma (4.22), Hodgkin's lymphoma (11.80), and multiple myeloma (2.3)), balanced by a deficit for all solid cancers (0.56), with a marked deficit for lung cancer (0.41). We found an excess for respiratory diseases (chronic obstructive pulmonary disease (1.86)) and genitourinary diseases (chronic renal failure (6.47)). There was marked geographical heterogeneity in the distribution of deaths. CONCLUSIONS: Though referring specifically to Italy, the results are informative for other countries and populations and all cases of CKS in general.

PEL, Kaposi's sarcoma HHV8+ and idiopathic T-lymphocitopenia CD4+.

We described a case report of a 36-year-old woman with a 10-year-history of idiopathic CD4+ T-lymphocitopenia and Kaposi's sarcoma HHV8+ who developed recurrent pleural effusion. Laboratory and instrumental tests with morphologic, immunophenotypic and molecular analysis of pleural sediment suggest us the diagnosis of primary effusion lymphoma (PEL). The term primary effusion lymphoma defines an extranodal non-Hodgkin's lymphoma HHV8-related, usually classified as a B-cell lymphoma, that grows in liquid-phase within body cavities. The case reported by the Authors appears to be of great interest for its epidemiological and clinical features.

Distribution of mosquito species in areas with high and low incidence of classic Kaposi's sarcoma and seroprevalence for HHV-8.

The 'promoter-arthropod' hypothesis, which postulates that exposure to the bites of certain species of haematophagous arthropods is an environmental risk cofactor linked to human herpes virus 8 (HHV-8) and Kaposi's sarcoma, was investigated in the Po River valley, northern Italy. The presence and density of adult female mosquitoes (Diptera: Culicidae) was determined by CDC light trap catches in two adjacent districts, at variance with respect to Kaposi's sarcoma incidence and HHV-8 seroprevalence. A total of 3910 specimens belonging to 11 species was collected in 34 rural sites (six municipalities) representative of the two districts. Five of these species are considered to be possible 'promoters' because of the irritation their bites cause humans: Aedes vexans (Meigen) and Ae. caspius (Pallas) (87% of sampled promoters), Culex modestus Ficalbi, Culiseta annulata (Schrank) and Coquillettidia richiardii (Ficalbi). Six are probable 'non-promoters': Cx. pipiens s.l., Cx. martinii Medschid, Anopheles claviger (Meigen), An. maculipennis s.l., An. plumbeus Stephens and Uranotaenia unguiculata Edwards. The density of promoters by site was correlated with the incidence rates of Kaposi's sarcoma at the district level (Pearson's r = 0.33, P = 0.06) and at the municipal level (r = 0.50, P< 0.01). Similar correlations emerged for non-promoters (r = 0.48, P< 0.01 and r = 0.42, P = 0.01, respectively). The density of promoters was higher than that of non-promoters in sites with livestock (odds ratio, OR = 2.8, 95% CI 2.2-3.6) and in municipalities with Kaposi's sarcoma cases (OR = 2.5, 95% CI 1.7-3.5). The study provides additional evidence of the association between the density of some mosquito species and Kaposi's sarcoma.

Classic Kaposi's sarcoma in Italy, 1985-1998.

To evaluate incidence rates (IRs) of classic Kaposi's sarcoma (CKS) in Italy after the spread of AIDS, we distinguished CKS from AIDS-related KS (AKS) using an 'ad hoc' record linkage procedure between 15 Cancer Registries (CRs) (21% of the Italian population) and the national AIDS Registry. Between 1985 and 1998, 874 cases of CKS and 634 cases of AKS were diagnosed in the study areas. CKS accounted for 16 and 27% of KS cases below 55 years of age in men and women, respectively, but for 91 and 100% of those above age 55. The IRs for CKS were 1.0/ in men and 0.4/100,000 in women, but they varied between 0.3 in Umbria and 4.7 in Sassari in men, and between 0.1 in Parma and 1.7 in Sassari in women. IRs of CKS in both genders were stable between 1985-1987 and 1993-1998. In Northern and Central CRs the IR (adjusted for age and gender) for CKS was 0.5 in individuals born in the same area, but 1.6 in individuals born in Southern Italy or in the Islands (rate ratio = 3.2) suggesting that KS-associated herpesvirus, the cause of KS, is acquired early in life.

Reduced seroprevalence of Kaposi's sarcoma-associated herpesvirus (KSHV), human herpesvirus 8 (HHV8), related to suppression of Anopheles density in Italy.

In two formerly malarious parts of Italy, age-related seroprevalence rates of Kaposi's sarcoma-associated herpesvirus [human herpesvirus 8 (KSHV/HHV8)] were determined from local blood donors and correlated with periods of vector control during anti-malaria campaigns. In Veneto, decreased KSHV/HHV8 seroprevalence in the 1951-1955 birth cohort coincides with the peak of DDT house-spraying. In Sardinia, where larviciding augmented indoor DDT-spraying, a significant drop of KSHV/HHV8 seroprevalence between 1945 and 1950 and 1951-1955 birth cohorts (P = 0.0046) coincides with suppression of the malaria vector Anopheles labranchiae Falleroni (Diptera: Culicidae). These results are consistent with age-related association between KSHV/HHV8 seroprevalence rates in native/resident populations and the density of malaria vectors in Veneto and Sardinia. This example supports our 'promoter arthropod' hypothesis on the role of haematophagous insects [putatively blackflies (Simuliidae), sandflies (Phlebotominae) and biting midges (Ceratopogonidae), as well as mosquitoes] when their bites induce hypersensitivity and immunosuppression, potentiate KSHV/HHV8 transmission via human saliva (when insect bite lesions are licked by another person whose saliva carries the virus) and may facilitate Kaposi's sarcoma.

Risk of soft tissue sarcomas and residence in the neighbourhood of an incinerator of industrial wastes.

AIMS: To investigate the association between occurrence of soft tissue sarcomas (STS) in Mantua and residence near an incinerator of industrial wastes. METHODS: Cases were subjects with histologically confirmed primary malignant STS diagnosed 1989-98 in the population resident in Mantua and in the three neighbouring municipalities. Controls were randomly extracted from population registries, matched for age and sex. Residential history was reconstructed for all study subjects since 1960. Main residence was geographically positioned according to GPS standards. RESULTS: The study included 37 STS cases (17 men and 20 women) and 171 controls. The incidence of STS in the area of study was estimated as 8.8 per 100 000 in men and 5.6 per 100 000 in women. The odds ratio associated with residence within 2 km, standardised by age and sex, was 31.4 (95% CI 5.6 to 176.1), based on five exposed cases. At greater distances, risk rapidly decreased, showing a fluctuation around the null value of 1. CONCLUSION: The study shows a significant increase in risk of STS associated with residence within 2 km of an industrial waste incinerator; an aetiological role of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can be hypothesised.

A one-generation cluster of malignant mesothelioma within a family reveals exposure to asbestos-contaminated jute bags in Naples, Italy.

Substantial evidence supports the role of asbestos in malignant mesothelioma. Clustering for this malignancy among relatives not only suggests genetic susceptibility as a relevant component but also provides a clue to investigate non-occupational sources of exposure. We identified five cases of malignant mesothelioma within one family with exposure to asbestos experienced during childhood, as 'next door' residents of a workshop recycling asbestos-contaminated jute sacks in Naples, Italy. This cluster discloses the health risk in the reuse of bags that previously had contained asbestos. Furthermore, it emphasizes the role of asbestos in the genetic-environmental interaction issue of malignant mesothelioma.

The bloodsucking arthropod bite as possible cofactor in the transmission of human herpesvirus-8 infection and in the expression of Kaposi's sarcoma disease.

Based on a review of the literature on human herpesvirus-8 (HHV8) and Kaposi's sarcoma (KS) and on the distribution of KS in Italy (Veneto region particularly), we hypothesize that the bite of bloodsucking arthropods is a cofactor in the seroconversion to HHV8 positivity and probably in the pathogenesis of KS. The bloodsucking arthropod releases with saliva powerful antihaemostatics and immunomodulators which may favour the replication and the establishment of the pathogen. Transmission would depend on the close contact of the child with a seropositive mother (or relatives) whose infective saliva is used to relieve itching and scratching at the arthropod bite's sites. During any deregulation of the immune system (e.g. ageing), local immune responses to new insect bites may induce virus activation which could prelude KS insurgence. The pathogen is not directly transmitted by the arthropod which merely prepares the cutaneous microenvironment for the virus. We have therefore introduced a new category of medically important arthropods, "promoter arthropods", besides those already defined as biological or mechanical vectors. Promoter arthropods are species able to induce in the host long-lasting, immediate or delayed-type hypersensitivity responses as well as local immunosuppression due to substances injected with their saliva. The striking variability of ORF-K1 gene of HHV8 could be due to the adaptation of the virus to the specific microenvironments resulting from the immune response to the salivary antigens characteristic of the bloodsucking arthropod species prevalent in each geographical area. It is worth noting that other viruses (especially Hepatitis B Virus) may exploit the same non-sexual transmission route.