586

problem of unsolicited data, generated by multichannelanalysers, which may be irrelevant to the patient’s condition.Of perhaps equal importance, but less obvious, is the

repetition of observations at unnecessarily short intervals.Much laboratory effort could be saved if sampling intervalswere matched more closely to the rate of change in theconcentration of the substance measured.

Department of Clinical Chemistry,Northwick Park Hospital,

Harrow, Middlesex HA1 3UJ. M. G. RINSLER.

CLASSIFICATION OF NON-HODGKIN’SLYMPHOMAS

SIR,-The announcement in The Lancet (Aug. 17,pp. 405-408) of two more classifications of non-Hodgkin’slymphomas encourages me to put forward my classificationof these classifications: ’

Well-defined, high-grade, oligosyllabicdiffuse

Poorly differentiated, polysyllabic circumlocutorywith dyslexogenesisUnicentric

derivativenlcentnc 1..Multicentric, cycnophilic (Gk. 1(U1(Vo!> = swan)

Cleaved and convoluted types Rappaport (non-Lukes)Cleaved and convoluted types Lukes (non-Rappaport)This system makes no claim to be comprehensive or even

comprehensible, so there may well be scope for otherclassifications of classifications and ultimately, one hopes, aclassification of classifications of classifications. At that

point we shall need a conference in the Caribbean.Royal Marsden Hospital,

Fulham Road,London SW3 6JJ. H. E. M. KAY.

ORIGIN OF MALIGNANT LYMPHOMAS

Sm,—In the past few years the B or T cell origin of thevarious malignant lymphomas has been the subject of manystudies, especially those employing immunological methods.However, the histological data on the initial involvementof the lymphatic tissue should also be taken into considera-tion. As has been well established for the lymph-node, onecan clearly distinguish a B-cell and a T-cell region.The B-cell region comprises the outer part of the cortex,especially the primary and secondary nodules. The T-cellregion is called the paracortical area, although we preferthe old term tertiary nodule.The first site of infiltration of a particular lymphoma

might give an indication of the origin of the tumour wheneither the B or T cell region is primarily affected. Wetherefore studied the early infiltration of lymph-nodes in8 cases of hairy-cell leukaemia (leuksemic reticuloendo-theliosis) and 8 cases of Sezary syndrome. In hairy-cellleukaemia we found that the infiltration was chiefly con-fined to the outer cortex, whereas the tertiary nodules wereat least partially intact in most cases. In contrast, in Sézarysyndrome the first infiltration took place in the tertiarynodules (" paracortical area "); apart from the influx of

Sezary cells through the afferent lymphatics, the primaryand secondary nodules were not affected at first.These findings speak in favour of the B-cell origin of

hairy-cell leukaemia and the T-cell origin of Sezary syn-drome. They are consistent with many experimental datalately reported.

Institute of Pathology,University of Kiel,Postfach 43 24,

D-2300 Kiel, Germany. K. LENNERT.

GREY-SCALE ULTRASONOGRAPHY INTHE INVESTIGATION OF OBSTRUCTIVE

JAUNDICESIR,-A common clinical problem is the differentiation

of obstructive jaundice due to multiple intrahepaticspace-occupying lesions from extrahepatic causes whichusually require surgical relief. In the presence of evenmoderate jaundice, the only radiological procedure of

possible value is transcutaneous cholangiography-ahazardous investigation which may precipitate surgery.Operation may be highly undesirable in the presence ofsevere and inoperable liver disease with defects of hxmo-stasis. Radioisotope examination is especially unreliable inthe presence of obstructive jaundice, since multiple smallmetastases are not adequately resolved and appear as

non-specific diffuse enlargement, while dilated portions ofthe biliary tree caused by extrahepatic obstruction producecold areas which simulate malignant involvement.

Grey-scale ultrasonography is done with a technicallysophisticated ultrasound scanner and produces a resolutionof a few millimetres in the liver substance.1 It has been

successfully applied to cancer diagnosis and solves theproblems of differentiating between intrahepatic and

extrahepatic causes of jaundice. The resolution whichmay be obtained and its use in this particular applicationare shown in the accompanying figures.

Fig. 1-Schema to show the plane of section and the displayedanatomy.

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Fig. 2-Ultrasonogram showing a parasagittal section 4 cm. tothe right of the midline.

The liver is bounded by the anterior abdominal wall (AAW),the diaphragm above (D), and the right kidney posteriorly (K).Multiple small black tumours can be seen replacing the normalliver substance.

1. Taylor, K. J. W., Carpenter, D. A., MaCready, V. R. J. zur.Ultrasound, 1973, 1, 284.