Conjunctival involvement in malignancy-associated acanthosis nigricans

Acanthosis nigricans classically presents with pigmented skin lesions over the neck, groin and axillae. It may involve the mucosal surfaces, particularly the oral mucosa. Conjunctival involvement is very rare, especially in the variety associated with malignancy. We report a case of acanthosis nigricans associated with squamous cell carcinoma of the bronchus where bilateral papillary conjunctivitis, progressing to hypertrophic papillary conjunctival and lid margin lesions, was the presenting feature. Topical treatment with corticosteroid and artificial tear drops resulted in the partial improvement of the ocular symptoms.

Morphological changes in the human corneal epithelium associated with surgical corneal clouding

Light microscopy and electron microscopy were used to define morphological changes occurring in human corneal epithelium during surgery. No correlation was established between preoperative medication or peroperative fluids and corneal epithelial clouding. It is suggested that the changes we observed in relation to epithelial clouding were the direct result of disturbance to endothelial pump functions.

Potential errors in the estimation of coronary arterial stenosis from clinical arteriography with reference to the shape of the coronary arterial lumen

Underestimation of coronary arterial stenosis at clinical arteriography has been explained by inadequate radiological views of crescentic or slit-shaped lumens. Postmortem perfusion-fixation of the coronary arteries at physiological pressures shows that most stenotic lesions result in circular, elliptical, or D-shaped lumens. Crescentic lumens in fully distended vessels are associated only with acute mural thrombus projecting into the lumen or with massive intra-intimal thrombus and plaque fissuring. Elliptical and D-shaped lumens, however, adequately explain the clinically observed phenomenon that some stenotic lesions can be seen only in one x-ray plane and not in another. It is no longer correct to postulate a crescentic or slit-like lumen. Furthermore, not only can elliptical and D-shaped lumens result in underestimation of stenosis, they may also result in serious overestimation. Lumens need only to deviate slightly from being circular for error to be introduced into the estimation of stenosis by currently used methods. The calculation of percentage stenosis from densitometric measurements or from computerised reconstruction of the arterial lumen is, however, more accurate.

The learning of radiological anatomy by medical students

Teaching radiographic anatomy to pre-clinical medical students is important as it relates anatomical studies to clinical medicine and the same time prepares them for the radiology they will encounter in their clinical years. A programme is described in which radiographic anatomy is comprehensively covered without proving too great a commitment to clinical radiologists. The programmes consist of exhibits of X-rays in the dissecting room, slide-lecture demonstrations and a permanent museum of radiological anatomy. This programme has worked well and there has been a very favourable student response.