Establishing the Causal Relationship between Polycyclic Aromatic Hydrocarbon (PAH) Exposure and Hepatic Neoplasms and Neoplasia-Related Liver Lesions in English Sole (Pleuronectes vetulus)

For almost 25 years our laboratory has studied the impact of PAHs and related industrial contaminants on benthic fish, following an interdisciplinary approach involving chemical exposure assessment linked to synoptic detection of various effects at several levels of biological organization. These data demonstrate a cause-and-effect relationship between neoplastic and neoplasia-related liver lesions in English sole, and exposure to PAHs, and to a lesser degree, chlorinated hydrocarbons such as PCBs. In statistical analyses of data from multiple field studies conducted since 1978, exposure to PAHs measured in various compartments has consistently been identified as a highly significant, major risk factor for neoplasms and related lesions in this species, with PCB exposure shown to be a significant, but less consistent and less strong risk factor for these lesions. A cause-and-effect relationship between PAHs and toxicopathic liver lesions in this species is further supported by the experimental induction of toxicopathic lesions identical to those observed in field-collected fish, in sole exposed in the laboratory to model carcinogenic PAHs such as BaP or to PAH-rich extracts of sediments from Eagle Harbor, a severely PAH-contaminated site in Puget Sound. More recent field studies have identified significant associations between hepatic cytochrome P4501A (CYP1A) induction and xenobiotic-DNA adduct formation, and hepatic lesion prevalences in wild subadult English sole. Field studies in Eagle Harbor subsequent to capping of the most PAH-contaminated region of this harbor with clean dredge spoils have shown a decline in exposure to PAHs as assessed by biliary fluorescent aromatic compounds (FACs) and hepatic xenobiotic-DNA adducts. This decline in PAH exposure has been accompanied by a dramatic decline in risk of occurrence of toxicopathic hepatic lesions in English sole from Eagle Harbor. Further, laboratory studies have induced lesions in English sole by injections of extracts from PAHcontaminated sediments. Overall, these findings relating to exposure to PAHs and chlorinated hydrocarbons and the occurrence of hepatic neoplasms and neoplasiarelated lesions in English sole fulfill the classic criteria for causality in epizootiological or ecological risk assessment studies, including: (1) strength of association, (2) consistency of association, (3) specificity of association, (4) toxicological and biological plausibility, (5) temporal sequence/timing (i.e., exposure precedes disease, effect decreases when the cause is decreased or removed), (6) dose-response or biological gradient, and (7) supportive experimental evidence.     

Spontaneous anaplastic large cell lymphoma in a chimpanzee: A clinicopathological and immunohistochemical study

Abstract: An anaplastic large cell lymphoma with disseminated abdominal metastases was diagnosed in a 35-year-old male chimpanzee. Clinically, the animal displayed lethargy, weight loss, ascites, and abdominal distention. Imaging studies showed several large abdominal masses. At necropsy, variably sized masses of neoplastic mesenteric lymph nodes that encompassed several intestinal loops were present throughout the abdomen. The largest mass measured 9 × 5 cm and had cauliflower-like protrusions into the jejunal lumen. The entire abdominal cavity was covered by a sheet of neoplastic tissue. Histopathologically, the tumor consisted of solid sheets of proliferating lymphoid cells forming a cohesive growth that filled the lymph node sinuses. The tumor had invaded the intestinal wall. Anaplastic large cell lymphoma was diagnosed from immunohistochemistry findings on the basis of positive reaction to the CD3 and CD30 markers and negative reaction to the CD20 marker. Serologic analysis revealed positive titers for Epstein-Barr, cytomegalo-, and varicella-zoster viruses. Both serologic and virologic studies showed no evidence of detectable retroviral infection. This type of tumor has not been reported before in the chimpanzee.     

A retrospective clinical audit of cervical smears reported as 'glandular neoplasia'.

The aims of this study were to review the diagnostic pathway of women with smears reported as 'glandular neoplasia' and to outline the management, colposcopy findings, treatment and final histological diagnosis in these women. The design was a retrospective review. A total of 114 women were identified over a 5-year period from the cytology database at the Royal Liverpool University Hospital Cytology Department, whose hospital case notes were available for review. Methods included a review of the case notes for the demographic details, indication for smear, colposcopic findings, investigation and/or treatment procedures, histology, final diagnosis and current disease status. Of 114 smears reported as 'glandular neoplasia', 67 were reported as consistent with cervical glandular intra-epithelial neoplasia (CGIN), six with endocervical adenocarcinoma, 36 with endometrial adenocarcinoma and five with other glandular neoplastic abnormalities. The average age was 46.5 years. 79 (69.3%) smears were routine call/recall and 36 (30.7%) women were symptomatic. The positive predictive value (PPV) for a significant histological abnormality in the CGIN smear group was 80.6% (23.9% invasive carcinomas, 43.3% CGIN and 13.4% CIN) and the PPV of an 'endometrial adenocarcinoma' smear was 86.1%. Smears indicating glandular neoplasia are associated with a high probability of clinically significant lesions, the PPV of a CGIN smear being over 80%. Immediate referral for colposcopy and assessment by an experienced colposcopist is recommended.     

Outcome of women with index smear showing mild dyskaryosis: effects of age and evidence of HPV infection

OBJECTIVE: Recent national guidelines (NHSCSP Document 20) recommend colposcopy referral after one mildly dyskaryotic smear, compared with the current practice of cytological surveillance and referral if the abnormality persists. The aim of this study was to identify the percentage of women whose first abnormal smear, showing mild dyskaryosis, returned to normal with cytological surveillance. Colposcopy could therefore be avoided in this group. This study also assessed whether age or human papillomavirus (HPV) status affected this outcome and the impact of non-attenders on the reliability of surveillance. METHODS: This was a retrospective study examining the follow-up of 1484 women whose first abnormal smear showed mild dyskaryosis between 1996 and 1998. The possible outcomes were: persisting abnormality referred to colposcopy, follow-up by cytology alone (negative follow-up), lost to follow-up or moved out of the area. Results were further assessed in terms of age (over or under 35 years) and cytological evidence of HPV effect. RESULTS: In this study 50.9% of women, presenting with a mildly dyskaryotic smear, returned to normal without colposcopy within the follow-up period of 6-8 years. Age (over/under 35) or cytological evidence of HPV did not significantly affect this figure. CONCLUSIONS: Immediate colposcopy would overtreat 50% of the study group resulting in 159 extra colposcopies in this unit per year. High-grade abnormalities were twice as prevalent (22% versus 11%) in the younger age group, suggesting that younger rather than older women would benefit from immediate referral.     

Cervical intraepithelial neoplasia grade III (CIN III) and invasive cervical carcinoma: the yawning gap revisited and the treatment of risk

In a 3-year study of the population of Southampton and south-west Hampshire there were 10 times as many cases of CIN III compared with invasive squamous carcinoma (700 compared with 70). The peak incidence of CIN III per 1000 screened women years was in those aged 25-29 years, which was 20 years earlier than the peak incidence of invasive cervical cancer per 1000 women years at risk. Ninety percent of CIN III was diagnosed in women under 50 years. There were 14 cases of cervical glandular intraepithelial neoplasia grade III (CGIN III), three coexisting with CIN III, all in women aged under 50 years: the gap between intraepithelial and invasive lesions was not seen for glandular neoplasia. Although referral was for at least moderate dyskaryosis in 86.8% of women with CIN III or CGIN III, most had been screened previously, either having had mild abnormalities requiring repeat cytology (39.8%) or negative cytology (34.5%). Only 12 women aged > or = 50 years had previous negative cytology: 21.4% compared with 35.6% of women aged < 50 years (P = 0.034). The results of this study suggest that the best opportunity for preventing invasive squamous cell carcinoma lies in screening women aged 20-39 years when the incidence of CIN III in the screened population is highest and before the peak incidence of invasive disease. The results also indicate the importance of repeated screening and follow up of minor cytological abnormalities in the detection of CIN III. The benefit of screening must be regarded as a treatment of risk, since it is almost certain that a high proportion of CIN III regresses or persists unchanged.     

Repeated intraspecific divergence in life span and aging of African annual fishes along an aridity gradient

Life span and aging are substantially modified by natural selection. Across species, higher extrinsic (environmentally related) mortality (and hence shorter life expectancy) selects for the evolution of more rapid aging. However, among populations within species, high extrinsic mortality can lead to extended life span and slower aging as a consequence of condition‐dependent survival. Using within‐species contrasts of eight natural populations of Nothobranchius fishes in common garden experiments, we demonstrate that populations originating from dry regions (with short life expectancy) had shorter intrinsic life spans and a greater increase in mortality with age, more pronounced cellular and physiological deterioration (oxidative damage, tumor load), and a faster decline in fertility than populations from wetter regions. This parallel intraspecific divergence in life span and aging was not associated with divergence in early life history (rapid growth, maturation) or pace‐of‐life syndrome (high metabolic rates, active behavior). Variability across four study species suggests that a combination of different aging and life‐history traits conformed with or contradicted the predictions for each species. These findings demonstrate that variation in life span and functional decline among natural populations are linked, genetically underpinned, and can evolve relatively rapidly.     

The plasticity of germ cell cancers and its dependence on the cellular microenvironment

So far, the understanding of germ cell cancer (GCC) pathogenesis is based on a model, where seminomas and non‐seminomas represent distinct entities although originating from a common precursor termed germ cell neoplasia in situ (GCNIS). Embryonal carcinomas (ECs), the stem cell population of the non‐seminomas, is pluri‐ to totipotent and able to differentiate into cells of all three germ layers, giving rise to teratomas or tumours mimicking extraembryonic tissues (yolk sac tumours, choriocarcinomas). With regard to gene expression, (epi)genetics and histology, seminomas are highly similar to GCNIS and primordial germ cells, but limited in development. It remains elusive, whether this block in differentiation is controlled by cell intrinsic mechanisms or by signals from the surrounding microenvironment. Here, we reviewed the recent literature emphasizing the plasticity of GCCs, especially of seminomas. We propose that this plasticity is controlled by the microenvironment, allowing seminomas to transit into an EC or mixed non‐seminoma and vice versa. We discuss several mechanisms and routes of reprogramming that might be responsible for this change in the cell fate. We finally integrate this plasticity into a new model of GCC pathogenesis, allowing for an alternative view on the dynamics of GCC development and progression.     

Atypical glandular cells in cervical smears: histological correlation and a suggested plan of management based on age of the patient in a low-resource setting

Objectives:  To perform an audit of all smears reported as atypical glandular cells (AGC) using the Bethesda system (TBS) 2001.
Methods:  A total of 18 376 cervical smears were screened from January 2005 to June 2007, of which 65 cases were reported as AGC. Follow-up histology was available in 31 cases (47.7%), in whom a detailed cytological/histological correlation was carried out.
Results:  AGC constituted 0.35% of all Pap smears. Follow-up histology was normal or benign in 20 cases, whereas a squamous or glandular abnormality was seen in 11 cases. Squamous abnormalities included one case each of cervical intraepithelial neoplasia (CIN)1, CIN2 and CIN3 and five cases of squamous cell carcinoma. All glandular epithelial abnormalities were endometrial in origin and included two endometrial adenocarcinomas and one uterine serous carcinoma. Neither in situ nor invasive adenocarcinoma of the endocervix was observed. Review of smears and reclassification as AGC, not otherwise specified and favour neoplasia revealed a higher proportion of abnormality in the latter group, reaffirming the utility of subtyping. The median age of women with AGC was 41 years. The outcome was analysed with respect to the median age. In women aged equal or more than 40 years, AGC reflected a high-grade squamous or glandular epithelial abnormality in 50% of cases compared with none in those less than 40 years old ( P  = 0.010).
Conclusion:  The age of the woman as well as the subtype of atypical glandular cells influences outcome and hence must be taken into consideration while formulating an acceptable management strategy in these women in a low-resource setting.     

Cytology and outcome of LSIL: cannot exclude HSIL compared to ASC-H

Objective:  The cytological features associated with clinical outcome of 'LSIL cannot exclude HSIL (LSIL-H)' in comparison with 'atypical squamous cells cannot exclude HSIL (ASC-H)' are incompletely described.
Methods:  LSIL-H and ASC-H Pap tests reported in a regional laboratory during a 13-month period were reviewed by two pathologists. Cytological features suspicious for HSIL were evaluated against a check list of 52 atypical features. All histology over 2 years of follow up for tests reclassified as LSIL-H and ASC-H was retrieved to determine clinical outcome. Atypical cytological features were correlated with outcome.
Results:  The review yielded 89 LSIL-H and 86 ASC-H. The highest ranked atypical cytological feature in each group was increased nuclear cytoplasmic ratio. Clinical outcome was positive (CIN II/III or AIS) in 44 (49%) LSIL-H and 33 (38%) ASC-H. Round ( P  = 0.02) and naked nuclei ( P  = 0.009) were significant correlates of outcome amongst LSIL-H tests, but no feature correlated with outcome in the ASC-H group.
Conclusions:  LSIL-H is different to ASC-H because of the 11% higher frequency of a positive outcome and the cytological features associated with outcome.     

The treatment of CIN: what are the risks?

The treatment of squamous cervical intraepithelial neoplasia is to remove or destroy the transformation zone (TZ). It is likely that no method of treatment is superior to another if it is performed properly and the limited available evidence supports this view. The significant advantages of excision (simplicity, cost, outpatient procedure, histological examination of the entire TZ) mean that treatment thresholds may have lowered over the last decade. Long-term pregnancy-related morbidity associated with excision has been reported recently. The evidence would suggest that this increase equates to a genuine increase in serious adverse outcome for cone biopsy but not large loop excision of the transformation zone (LLETZ). The available data also point to an increase in both incomplete excision and premature labour associated with the excision of large endocervical TZs. The clinical implications arising from this are firstly that women with large type 2 and 3 TZs need appropriate counselling before treatment and that the threshold for treating young women with mild abnormalities needs review.