A survey of the incidence of monocyte esterase deficiency in 4000 inpatients (including 808 with malignant neoplastic disease) and 474 normal controls was performed using an automated esterase method. A highly significant excess of patients with malignant disease and the deficiency was evident when compared with normal controls or all other patients. Within the group of patients with malignant disease the demonstrable excess occurred in B chronic lymphocytic leukaemia, non-Hodgkin's and Hodgkin's lymphoma, and carcinoma of the gastrointestinal tract. There was also a significant excess of patients with the deficiency attending the renal unit, both among patients who had had renal transplants and those who had not. A familial incidence of monocyte esterase . deficiency was found in 19 (35%) of first degree relatives of those patients in whom family studies were done.It is suggested that the reason for the increased prevalence of the anomaly in these disorders might be that the diminution of esterase activity has a role in their development.

Monocyte-enriched and lymphocyte-enriched fractions of peripheral blood from three healthy volunteers were obtained by percoll density gradient centrifugation. The cytotoxic activity of each fraction against 51Cr-labelled K562 cells was quantified in a 2-h assay using freshly isolated cells of each fraction and cells of each fraction which had been incubated with and without lactoferrin in complete medium for 18 h before performing the assay. We have thereby shown that cytotoxicity was not demonstrable in the lymphocyte fraction (containing 7.3 +/- 2% large granular lymphocytes) after 18 h in medium, whereas the cytotoxicity of the monocyte fraction (containing 3 +/- 0.4% large granular lymphocytes) was still significantly increased (P less than or equal to 0.01) and that lactoferrin had no effect on lymphocyte fraction cytotoxicity while producing an 11-fold increase in the cytotoxicity of the monocyte fraction. It is therefore possible to perform a relatively simple test of monocyte cytotoxicity using lactoferrin as a stimulant in a 2-h 51Cr-labelled K562 assay system by allowing 18 h to elapse for lymphocyte natural killer cytotoxicity to decay.

Summary. Cytochemical staining of monocyte-specific esterase (MSE) is widely used for identification of the monocytic lineage in leukaemias. Deficiency of this enzymatic activity occurs as a familial trait and the deficiency has been shown to occur with greater frequency in patients with lymphoproliferative or gastrointestinal malignant neoplastic diseases than in normal blood donors. Reverse transcriptase polymerase chain reaction (RT-PCR), sequencing and quantification by Northern blot analysis was conducted on the MSE mRNA of 12 subjects with monocyte esterase deficiency (MED) and seven MSE-positive subjects to examine whether mutations were present or whether the defect was quantitative. Mutations were not found in the mRNA sequences. However, MED subjects had significantly less MSE mRNA than MSE-positive subjects (P 0´001). These findings show that deficiency of monocyte esterase activity in MED is not as a result of the presence of inactive isoenzymes and may be owing to an abnormality in the regulation of mRNA production.

We reviewed the relative incidence of histological sub-types of thyroid carcinoma at St. Vincent's Hospital between 1970 and 98 Vol. 162 No. 3 1991 and compared survival rates. The findings were compared with previous reports between 1946 and 1970.Patients with thyroid carcinoma from 1970 through 1991 were identified and pathological and clinical data retrieved.Of 141 patients identified, 113 were female and 28 male. Fiftyseven patients had papillary, 41 follicular, 24 anaplastic and 6 medullary carcinoma. There were 10 lymphomas and 3 thryoid metastases. The 10-year actuarial disease-free survival for papinary carcinoma was 93%, follicular 80% and medullary 37%. The median overall survival for anaplastic carcinoma was 5 months. The number of cases seen increased from 2.2 per year between 1946 -1965 to 7.6 per year between 1982-1991 . From 1946to 1991 the relative incidence of papillary carcinoma increased from 19% to 57%.Of interest is the change in relative incidence of the histological sub-types. Follicular carcinoma is associated with endemic goitre and increased iodine intake may explain its reduced incidence. Increased radiation may explain the increase in papillary carcinoma. There is a need for a National Tumour Registry to see if this local trend is reflected nationally. PROTEOLYTIC ENZYMES AS PROGNOSTIC MARKERS IN BREAST CANCER

MED. (J7 Clin Pathol 1995;48:768-770)