Until recently, the influence of basal liquid water on the evolution of buried glaciers in Mars' mid latitudes was assumed to be negligible because the latter stages of Mars' Amazonian period (3 Ga to present) have long been thought to have been similarly cold and dry to today. Recent identifications of several landforms interpreted as eskers associated with these young (100s Ma) glaciers calls this assumption into doubt. They indicate basal melting (at least locally and transiently) of their parent glaciers. Although rare, they demonstrate a more complex mid-to-late Amazonian environment than was previously understood. Here, we discuss several open questions posed by the existence of glacier-linked eskers on Mars, including on their global-scale abundance and distribution, the drivers and dynamics of melting and drainage, and the fate of meltwater upon reaching the ice margin. Such questions provide rich opportunities for collaboration between the Mars and Earth cryosphere research communities.

With human influences driving populations of apex predators into decline, more information is required on how factors affect species at national and global scales. However, camera-trap studies are seldom executed at a broad spatial scale. We demonstrate how uniting fine-scale studies and utilizing camera-trap data of non-target species is an effective approach for broadscale assessments through a case study of the brown hyaena Parahyaena brunnea. We collated camera-trap data from 25 protected and unprotected sites across South Africa into the largest detection/non-detection dataset collected on the brown hyaena, and investigated the influence of biological and anthropogenic factors on brown hyaena occupancy. Spatial autocorrelation had a significant effect on the data, and was corrected using a Bayesian Gibbs sampler. We show that brown hyaena occupancy is driven by specific co-occurring apex predator species and human disturbance. The relative abundance of spotted hyaenas Crocuta crocuta and people on foot had a negative effect on brown hyaena occupancy, whereas the relative abundance of leopards Panthera pardus and vehicles had a positive influence. We estimated that brown hyaenas occur across 66% of the surveyed camera-trap station sites. Occupancy varied geographically, with lower estimates in eastern and southern South Africa. Our findings suggest that brown hyaena conservation is dependent upon a multi-species approach focussed on implementing conservation policies that better facilitate coexistence between people and hyaenas. We also validate the conservation value of pooling fine-scale datasets and utilizing bycatch data to examine species trends at broad spatial scales.

A case is presented of a patient with bilateral retinoblastoma, treated at infancy with surgery, chemotherapy and radiotherapy, who subsequently developed at least four additional histologically distinct malignancies: a Ewing sarcoma of the left fibula, two extraskeletal osteosarcomas of the left lower extremity, a mucoepidermoid carcinoma of the right parotid gland and a squamous cell carcinoma of the left paranasal cavity.

In addition to retinoblastoma, patients with a germline RB-1 mutation are at high risk of second primary malignancies. An additive carcinogenic effect of cytotoxic therapy in these patients has been assumed. Patients with hereditary retinoblastoma should be under life-long follow-up programmes including a regular head and neck examination for detection of new primaries, especially in the radiation field of the presenting retinoblastoma.

The risk for post-operative exposure of the carotid artery due to skin flap necrosis after major head and neck surgery is increased after previous radiation and in severely malnourished patients. Eight patients are described who presented with an (imminent) carotid exposure one to eight weeks after surgery. Pectoralis major myofascial flap transfer with split thickness skin graft coverage was used for protection of the carotid artery. All cases were managed successfully and healed primarily in two to four weeks with acceptable cosmesis. We advocate immediate treatment in the event of an exposed carotid (or imminent exposure) by a pectoralis major myofascial flap with split-thickness skin grafting.

In order to study the induction of malignancy in normal tissues due to ionizing radiation, we reviewed the files of 2500 patients with a tumour of the head and neck treated at the Netherlands Cancer Institute (Antoni van Leeuwenhoek Ziekenhuis), Amsterdam, from 1977 to 1993. We then checked whether or not these patients had been previously irradiated. Patients with a thyroid carcinoma or skin cancer were excluded from the study, since it is generally known that previous irradiation is a risk factor in these tumours. Eighteen patients were found to have a malignancy within a previously irradiated area (0.70 per cent). The mean interval between radiation and diagnosis of the head and neck tumour was 36.5 years. There were five soft tissue sarcomas, nine squamous cell carcinomas and four salivary gland tumours. Fourteen patients were operated upon whereas four received palliative treatment only. The median survival of the total group was 3.5 years. Particularly. in young patients because of the better cancer therapy and prolonged survival one must be aware of the increased risk of radiation-induced tumours.

Soft tissue sarcomas in the head and neck are rare. Aetiological factors relating to these tumours have not yet been identified. The association with von Recklinghausen's disease andwith irradiation is however well recognized. In the literature it has been speculated that trauma may also play a role in the development of soft tissue sarcomas. In this article we present five patients with a history of surgical trauma at the site where a sarcoma later developed. Although we cannot prove a causal relationship, the relatively high incidence of possibly trauma-related soft tissue sarcomas in a series of 60 patients we have seen over a 30-year period, suggests that such a relationship could exist.

Sixteen squamous cell carcinomas of the tonsillar region and 13 carcinomas of the base of the tongue were studied in a search for significant differences between the tumours of these two oropharyngeal subsites, which are known to carry a significantly different prognosis. The characteristics of the tumour cells and the tumourhost relationship were scored on H & E-stained slides, as well as on slides stained with a panel of antibodies. The results obtained were cross-tabulated and analysed with respect to the subsite. Ten variables were tested: cytonuclear pleomorphism, mitotic activity, the presence of atypical mitoses, keratinization, tumour grade, presence of eosinophils, severity of inflammatory response, and the expression of keratin-10, blood group antigens and collagen IV. When split up by site, only cytonuclear pleomorphism revealed a significant difference, tonsillar carcinomas more often exhibiting marked pleomorphism (p=0.04).

Despite having some prognostic relevance for squamous cell carcinomas of the head and neck, the variables tested could not provide an explanation for the difference in biological behaviour of the tumours studied.

Neurofibromatosis (NF) or von Recklinghausen's disease is frequently accompanied by malignant tumours, which can occur at any site in the body. These malignancies are mainly of soft tissue origin. Of all head and neck malignancies, the number of soft tissue sarcomas is limited and in combination with NF this type of tumour is a rare event. In this report we describe the clinical course of a young female patient with NP, who presented with a massive malignant schwannoma in the parapharyngeal space, and review the pertinent literature.

An 18-year-old woman with insulin-dependent diabetes mellitus developed an infection of the paranasal sinuses with Rhizopus oryzae resulting in facial swelling, hemiplegia and blindness of the right eye. The therapy of this rhinocerebral mucormycosis consisted of extensive surgical debridement, administration of high-dose amphotericin B, hyperbaric oxygen and control of the underlying predisposing diabetes mellitus. The patient eventually recovered with however, the loss of one eye.

Permanent blindness, is a very rare, but devastating complication of simultaneous bilateral neck dissection. Most otolaryngologists/head and neck surgeons are unaware that amaurosis can result from this surgery, and this paper is meant as a poignant reminder of that end. A case report is presented, followed by a discussion of possible aetiology; a management protocol is proposed.