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Annotations

FROZEN SECTION

THE purpose of a frozen section is not to make a

diagnosis: it is to arrive at a therapeutic decision. Anexact histological and even cytological description is oftenpossible and always satisfying; but it is never necessary.More often than not all that needs to be decided is whetherthe lesion is malignant or not. But confusion of purposeis not the only reason why the frozen section still does notoccupy what its advocates claim to be its rightful place insurgical diagnosis. Ackerman and Ramirez 1 deplore thatthe method is still used by some merely " to satisfy thesurgeon’s intellectual curiosity or to prove that there is apathologist in the hospital ": and the procedure can

certainly degenerate into a kind of parlour-game where ateam of super-doctors must arrive at histological diagnoseswithout knowledge of the patients’ history or physicalsigns. That in conscientious and experienced hands theexamination of frozen sections can provide accurate anduseful information was clearly shown by Ackerman andRamirez. Their material consisted of 727 tumours (611of which were malignant) and 542 non-neoplastic lesions.The overall accuracy was 98°,o : they had made 4 falsepositive and 22 false negative diagnoses.

Apart from possible diagnostic errors and very occasionaltechnical difficulties, tumour implantation is often men-tioned as a risk of biopsy. That it can happen is not indoubt: the more one looks for it, the more abundant is theevidence. Whether the risk is great is another matter. Itmust be exceedingly rare for a previously confined andtherefore curable tumour to be converted into an incurableone by surgical dissemination: it seems more likely thatthe knife (or even more the blunt dissector, the impatientfinger, the crudely handled swab, or the capricious sucker)merely opens up additional avenues to intrinsically invasivecells. None the less, precautions can and should be taken;and the possible risks should always be balanced againstthe potential benefits. Thus, when at operation a doubtfulmass is encountered in the cxcum, Ackerman and Ramirez

wisely recommend an ileohemicolectomy without pre-liminary frozen section: the risks of the operation, even ifthe lesion should prove innocent, are less than the risks ofdissemination by biopsy if it should be malignant. On theother hand, despite the danger of tumour implantation,the mortality of a radical pancreaticoduodenectomy is suchthat the risks entailed in frozen-section biopsy are out-weighed by the chance, however remote, that it mightexonerate a doubtful pancreatic lesion.The most common site for frozen-section biopsy is the

breast; and in Ackerman and Ramirez’ series of 440 sectionsfrom breast lesions 263 were tumours. Of these, 205 weremalignant. Diagnosis had to be deferred in 10 cases;but the only actual errors were 4 false negatives. Toachieve such accuracy a more than perfunctory coopera-tion between surgeon and pathologist is essential. This isoften preached but not so often practised. Many a morbidanatomist who pronounces on frozen sections as part ofhis daily routine has not set foot in the operating-theatreor ward for years. Such pathologists will often argue (andargue with a grain of justice) that it is the surgeon’s task toinvite them: it is with the surgeon that responsibility forthe patient’s welfare ultimately rests, and he knows (orshould know) that the accuracy of a frozen-sectiondiagnosis depends in no small measure on the pathologist

1. Ackerman, L. V., Ramirez, G. A. Brit. J. Surg. 1959, 46, 336.

knowing where the section came from or even guiding thesurgeon in his choice. If, however, a few morbidanatomists are all too ready to compromise, the attitudeof some of their surgical colleagues is no less curious.Though microphotographs are still de rigueur for

" serious " surgical papers, many authors have not lookeddown a microscope since student days. This state ofaffairs would have horrified their masters fifty years

ago much as it would horrify surgeons today if some-

body suggested that, having ascertained the size, shape,position, mobility, and sensitivity of a lump, they shouldcall in a physicist to tell them whether or not it is fluctuant.The bulk of morbid anatomy is easy: often a glance by afirst-year clinical student will give the answer whetherthe lesion is cancerous or innocent. Why is that glance sorarely cast by surgeons ? Perhaps it would dispel themystique which may be an unacknowledged attraction ofthe method.

In many sites-such as the thyroid and prostate-Ackerman and Ramirez suggest that frozen-sectiondiagnosis has a wider scope than it is generally given.Their personal experience is impressive; but perhaps theyunderestimate the confusion in nomenclature which, inmost hospitals, still bedevils clinicopathological collabora-tion. Often what is cancer to the pathologist is not cancerto the clinician-and sometimes what is cancer to both isnot cancer to the patient. Pathologists are becomingincreasingly aware of grades of biological malignancywhich do not necessarily correspond to histological malig-nancy and which they are yet unable to express. To mostclinicians, on the other hand, " cancer " still spells doomunless radically treated; and to most patients in this

country it spells doom unqualified. In the Americanseries the discrepancy between the numbers of false

negatives and false positives may be significant. On

a-priori grounds there is no valid reason for this difference:if the conscientious pathologist will think twice beforepassing sentence of malignancy, he will be equally reluc-tant to jeopardise the patient’s chances of cure by undueoptimism. Whereas death from malignant spread, how-ever, can incontestably prove a negative diagnosis false, apositive diagnosis is not easily disproved. Cancer may be

diagnosed on a frozen section from the prostate and con-firmed on the radical-operation specimen. This still doesnot necessarily mean that, had it been left behind, it wouldhave shortened the patient’s life by a single day.2 Thenumber of false positives may thus be higher thanstatistics suggest.

2. See Lancet, Feb. 21, 1959, p. 398.3. Bassett, S. H., Van Alstine, H. E. J. Nutr. 1935, 9, 175.4. Word, A. H., Wakeham, G. Univ. Colo. Stud. 1938, 25, 181.5. Flear, C. G. T., Hughes, P., McLellan, A. Brit. J. Nutr. 1959, 13, 54.

ERRORS IN DIETARY CONTENT

STANDARDISATION of diets with particular reference totheir electrolyte content has become increasingly impor-tant in investigation and treatment. Whereas diets wereonce defined in the most general terms such as

" low fat "

or " high protein ", considerable precision is now impliedby " diet to contain 10 mEq. (or less) of sodium daily ".Yet in aiming to be so precise we may be deceiving our-selves ; for what is ordered is not necessarily what thepatient actually eats. Day-to-day variation in the con-stituents of a constant diet has previously been reported 3 4but has largely been ignored in recent years.

In a timely investigation Flear et al." have analysedthe sodium, potassium, and chloride content of two diets(provided for balance studies), and compared their results