DIAGNOSTIC APPLICATIONS OF THE BLOOD-COUNT 285 



and according to H order it may reach 25,000. I have several 

 times met with 20,000 or thereabouts. Tuberculous pleurisy 

 is usually without marked leucocytosis, but occasionally the 

 figures are too inconstant to be of much value in diagnosis. 



SYPHILIS. There is usually progressive secondary anaemia 

 with moderate leucocytosis (12,000 to 16,000), due mainly to 

 increase of lymphocytes, often of the large type, but the 

 figures are too inconstant to be of much value in diagnosis. 



PURPURA PI^MORRHAGICA. There is naturally advancing 

 anaemia, which may be associated with a low or normal colour- 

 index. In the most common, type of cases, in which the prog- 

 nosis is relatively good, there is also the usual slight poly- 

 nuclear leucocytosis met with in secondary anaemia, or it may 

 reach a very high gTade. In some cases, however, in which 

 the prognosis is extremely bad, there is leucopenia with lym- 

 phocytosis. In one case (under Dr. Dalton at King's College 

 Hospital) which was fatal in a few days the leucocytes were 

 2,000 and the lymphocytes over 95 per cent. A blood-count 

 should always be made in purpura haemorrhagica, when these 

 cases (probably quite different in nature) may be diagnosed 

 early and their gravity recognized. 



MALIGNANT TUMOURS. These are frequently associated 

 with a moderate leucocytosis, with increase of the poly- 

 nuclears, and slight anaemia. The leucocytosis is said to be 

 more marked in the sarcomata than in the carcinomata. These 

 facts are very rarely of value in diagnosis, since while the 

 growth is small and removable the blood is usually normal 

 (except in an ulcerated carcinoma of the gastro-intestinal 

 tract), and in any case there are so many examples of malig- 

 nant growth with normal blood, and so many causes of slight 

 leucocytosis, that its presence is not much help. Malignant 

 tumours of the oesophagus are occasionally unaccompanied 

 by leucocytosis, but most follow the general rule. 



CANCER OF THE STOMACH. The frequency with which diffi- 

 culty arises in the early diagnosis of this condition renders 

 any assistance important, and although the indications given 

 by the blood-count are not conclusive, they are helpful in con- 

 junction with the clinical examination and the investigation of 

 the test meal (see p. 162). In some cases the blood is normal, 

 but usually there is one or two conditions : either a marked 

 secondary anaemia with a rather low colour-index (averaging 



