The histology and growth kinetics of canine renal oncocytoma.

A renal oncocytoma was diagnosed in a 10-year-old English springer spaniel with a 5-month history of anorexia, vomiting and weight loss. The tumour, which was localized to the kidney, was treated by simple nephrectomy and the dog made a full recovery. Histologically, the tumour consisted of cells with abundant eosinophilic cytoplasm forming acini and alveolar nests set within a loose fibrovascular stroma. The results of cell kinetic studies (AgNOR score 2.68, PCNA index 5.2%) were comparable with findings reported for benign human renal tumours. This appears to be the first reported case of renal oncocytoma in a dog.

Pathophysiology of overheating in a piglet model: findings compared with sudden infant death syndrome.

OBJECTIVE: To examine the nature of hyperthermia-induced pathophysiological changes in an animal model including effects on lung compliance. METHODOLOGY: Piglets were randomly assigned to heated or non-heated groups. Heated animals were warmed to 4 degrees C above normal body temperature while sedated and breathing spontaneously. Cardiorespiratory variables were recorded serially and haematological assessments and blood cultures taken at 0 and 6 h. After 6 h the animals were killed and a limited postmortem was performed. Control animals had all procedures without heating. RESULTS: Heated piglets developed tachycardia, hypotension and a metabolic acidosis in addition to tachypnoea, hypocapnic alkalosis and a neutrophil leucocytosis. Rectal temperature after death fell at the same rate in both groups. Lung histology revealed an excess of lung haemorrhage and alveolar oedema in the heated group. No significant group differences in dynamic lung compliance were demonstrated. CONCLUSIONS: The pathological changes that occur during hyperthermia are non-specific but not incompatible with those found in sudden infant death syndrome. There was no confirmation of the thesis that hyperthermia causes death by altering lung compliance.

Necrotising fasciitis: a single centre's experience.

AIMS: Necrotising fasciitis is a rare but serious soft tissue infection with high morbidity and mortality. We wished to review our 5 year experience with this condition 1989-94. In addition, in light of recent interest in the association between necrotising fasciitis and nonsteroidal antiinflammatory drugs, we wished to determine the incidence of NSAID use in our necrotising fasciitis patients. METHODS: A review of all Dunedin Hospital cases of necrotising fasciitis between January 1989-June 1994 was undertaken. Subsequently all specialists involved in treating the patients audited the notes, particularly regarding clinical presentation, complications, treatment, outcome and concomitant use of NSAIDs was also recorded. RESULTS: There have been seven patients (4 males) with a mortality rate of 43%. Survival was associated with early diagnosis, rapid and intensive medical and surgical intervention, and possibly the early use of haemofiltration. Five of the seven patients had ingested nonsteroidal antiinflammatory drugs (NSAID) prior to their presentation which may have potentiated the severity of the endotoxic shock. CONCLUSION: Necrotising fasciitis remains a potentially lethal disease but early management and aggressive treatment improves outcome. A high index of suspicion, avoidance of NSAIDs, and aggressive multidisciplinary team management of these patients offers the best chance of survival in necrotising fasciitis.

A clinicopathological study of loop recession in strabismus.

This communication reports the histological structure of loop recessions of extraocular muscles from seven patients. In all cases the loops formed pseudotendons in which the typical histological structure was well established by four months. Subsequently, moulding of these pseudotendons occurred with improved alignment of collagen and decrease in vascularity. By three and a half years after the operation the pseudotendon had acquired a very close resemblance to true tendon.

Temporal change in diagnostic criteria as a cause of the increase of malignant melanoma over time is unlikely.

To assess whether the increase in malignant melanoma incidence could be due, at least in part, to changes in histological criteria of malignancy, pathologists in Australia, France, Italy, New Zealand, Norway, Sweden, the United Kingdom, the United States and the USSR reviewed diagnoses of 50 consecutive pigmented naevi (40 junctional and compound; 10 intradermal) and 20 consecutive malignant melanomas made in each participating centre around 1930, around 1955 and around 1980. Collaborating pathologists re-read the material, 2,665 cases in all, either from the original slide (82%) or from a recut block (17%), gave their diagnosis and indicated whether the lesion was benign (B), dubious benign (DB), dubious malignant (DM) or malignant (M). As the distribution of review diagnoses was much the same whether the original slide or one made from a recut block was read, the material was pooled. Overall, 2.8% of cases originally reported as B/DB were reviewed as DM/M, while 4.4% of the DM/M diagnoses were held to be B/DB. The shifts between categories were greatest around 1955 and least around 1980, suggesting increasing uniformity of interpretation. All available blocks were recut and sections sent to IARC for review: 1.7% (22) of 1293 B/DB diagnoses were considered to be DM/M and 3.3% (18) of 551 DM/M diagnoses were considered to have been B/DB. The consistently low frequency of shift in diagnostic category, whether the material was reviewed in the collaborating laboratories or by one pathologist at IARC, in a study designed to give maximum attention to those lesions--the junctional and compound naevi--in which a change in opinion as to malignancy would be most likely to arise, suggests that pathologists, irrespective of geographical location, are using common criteria. These findings argue against changes in histological interpretation as being responsible for more than a small portion of the continuous increase of some 3% to 8% per annum observed in malignant melanoma incidence. Other explanations, such as an increase in the frequency or potential for malignant transformation of precursor lesions, must be sought. The anatomical distribution of the malignant melanomas examined followed the usual site pattern by sex, and their thickness was observed to decrease over the period of the study in most centres.

Fatal high cervical spinal cord injury in an automobile accident complicating os odontoideum.

We report a case where spinal instability from incomplete fusion of the dens of C2 (os odontoideum) allowed anterior displacement of the skull and first cervical vertebra following right frontal impact against the A pillar in an automobile accident. Resultant crushing and laceration of the spinal cord occurred at the level of C1 and C2. Without either radiographic investigation or detailed examination of the spine, the fatal injury might have been overlooked and death attributed to acute alcoholic poisoning because the blood alcohol level was .613%.

Vertebral artery occlusion associated with closed head injury: report of three cases.

Vertebral artery occlusion associated with closed head injury is an uncommon clinical entity. Three cases are presented with discussion of the mechanisms of injury, pathology, diagnosis, possible treatment modalities and autopsy findings in the two fatalities. Angiography is essential for diagnosis and in fatal cases post-mortem examination of the entire length of the vertebral arteries should be routine.

Haemorrhagic shock encephalopathy syndrome.

Haemorrhagic shock encephalopathy syndrome is a recently described condition which appears to be an important cause of infant mortality and morbidity. Six infants, with some features of this condition, admitted to Dunedin Hospital during the last three years, are presented and their diagnoses reviewed. Diagnostic overlap may occur between haemorrhagic shock encephalopathy syndrome, hypoxic-ischaemic encephalopathy and near miss sudden infant death syndrome. An investigative approach to the infant with shock and acute encephalopathy is outlined.

Unilateral pulmonary edema complicating chest compression and cardiac avulsion.

A 16-year-old male passenger involved in an automobile accident was observed at autopsy to have total avulsion of the heart from its vascular connections and severe unilateral pulmonary edema. The nature of the injuries and the circumstances of the accident revealed that this finding was not an indication of survival of even limited duration. The possible pathogenesis of the pulmonary edema in the context of the injuries received by the victim are discussed.

The 'morning glory syndrome' - a mesodermal defect?

The clinical, ultrasonographic, CAT scan and pathologic findings are described in a case of a rare unilateral malformation involving the optic disc of the type described as the 'morning glory syndrome'. The malformation was associated with a peripapillary scleral defect, absence of the lamina cribrosa and a recess formed by an axial retrodisplacement of the optic nerve. There was an associated secondary exudative retinal detachment with retinal atrophy and gliosis; the retinal pigment epithelium showed peripapillary proliferation. Additional features included: (a) an apparent schisis in the retina within the retrobulbar recess, (b) an absence of the perineural meninges which were replaced by fibroadipose tissue and bundles of smooth muscle, (c) peripheral optic nerve atrophy and (d) a vascular plexus surrounding the central retinal artery.

Cell necrosis and endocytosis (apoptosis) in an embryonal rhabdomyosarcoma of the orbit.

An orbital embryonal rhabdomyosarcoma, which was excised from the orbit of an 8-year-old girl, was studied by light microscopy and transmission electron microscopy. Cells within the tumour demonstrated by light microscopy diffuse areas of necrosis and isolated single-cell necrosis. There were many viable tumour cells with intracytoplasmic vacuolar structures which contained basophilic granules. Ultrastructural studies showed close apposition between well-preserved tumour rhabdomyoblasts and degenerate or necrotic tumour cells: degenerate cells and condensed cell fragments were observed within the cytoplasm of the well-preserved tumour cells. Some cells which showed degenerative changes had features which suggested that they had ingested more than one degenerate cell on separate occasions. This phenomenon may be regarded as a variant of selective individual cell death, currently referred to as apoptosis, which has not been previously reported in a case of embryonal rhabdomyosarcoma. The patient remains free of tumour recurrence four years following treatment with combined radiotherapy and chemotherapy.

Sudden death from occlusive disease of the atrioventricular node artery.

Non-atherosclerotic focal occlusive disease of the atrioventricular node artery was the only significant pathological lesion found at autopsy in 2 individuals aged 40 and 17 yr who died suddenly and unexpectedly. The cases were observed amongst 115 autopsies categorized as sudden cardiac death and performed during an 18 mth period. Occlusive disease of the atrioventricular node artery is a poorly documented entity of unknown aetiology and pathogenesis. We believe it is a more frequent pathological finding in sudden cardiac death than has been previously recognized and that it deserves more attention than it currently receives.

Adenomatoid hamartoma of the lung in a neonate.

A case of adenomatoid hamartoma in a premature male infant is described and the recent literature is reviewed. The present case demonstrates the frequently associated features of maternal hydramnios of late onset, and premature delivery with foetal respiratory difficulty and anasarca.