BERKITTA LYMPHOMA (D. Burkitt, English doctor; a synonym a lymphoma African) — the malignant lymphoid tumor which is localized hl. obr. out of limf, nodes (an upper jaw, kidneys, ovaries).
First descriptions of a disease, apparently identical B. of l., occur in reports of the English missionaries in Uganda at the end of 19 century. However only in 1958 Mr. Berkitt established nosological independence of the disease bearing now his name. Later the second big center of B. of l was revealed. in Asia (Papua and New Guinea).
Maximum incidence of B. of l. it is established in Kenya, Tanzania, Nigeria, Zaire and Southern Rhodesia, Papua and New Guinea. In Ibadan (the Western Nigeria) on B.'s share of l. 70% of all malignant new growths at children are necessary. With a smaller frequency of B. of l. meets in the Republic of South Africa, Ghana, India. Isolated cases of B. of l. are described in many other countries. Uneven distribution of B. of l. in the certain countries of Africa and Asia it is connected with restriction of a zone of its distribution with certain climatic parameters. B.'s incidence of l. depends on age. So, it practically does not occur at children of the first two years of life, but from 3-year age quickly accrues, reaching a maximum by 6 — 7 years, and then decreases by 15 years. 98% of cases of B. of l. it is the share of age more young than 20 years, at the same time 50% of patients — children of 5 — 9 years. Men are ill twice more often than women. In the USSR B. of l. it is not described.
Accurate dependence of prevalence of B. of l. in Africa from humidity and ambient temperature allowed Berkitt and Davis (J. N. Davies) to make a hypothesis of transmissible character and the virus nature of a disease; really, «the limfomny belt» territorially matches a zone of dwelling of some mosquitoes from the sorts Anopheles and Mansonia. It is known that the lower temperature bound of «a limfomny belt» matches temperature, at a cut reproduction of a number of viruses (a dengue, yellow fever) and, perhaps, a virus B. of l stops. In culture of cells of B. of l. elektronnomikroskopichesk were found the inclusions characteristic of the gerpesopodobny, DNA-containing viruses. The same is confirmed also on biopsy material. From culture of cells of B. of l. To Epstein and Burra (M. of A. Epstein, J. The m of Barr, 1964) was succeeded to allocate a virus. By immunization of rabbits this virus received the serum which is specifically interacting in reaction of an immunofluorescence with lymphoblasts from culture of cells of B. of l.
By method immunofluorescence (see) antibodies to Epstein's virus — Burra and in sick B.' serum of l were found. The reaction of an immunofluorescence which is carried out with viable cells of biopsirovanny material and sick B.' serum of l., it was highly specific. If instead of cells of biopsirovanny material normal cells of marrow, an immunofluorescence negative take. High degree of correlation between detection of virus particles by means of a supermicroscope and positive reaction of an immunofluorescence is shown.
In addition to sick B. of l., antibodies to Epstein's virus — Burra find in blood of many healthy people, but with special constancy — in patients with an infectious mononucleosis (see. Mononucleosis infectious ). It demonstrates etiological proximity of both diseases, but calls into question a role of a virus of Epstein — Barre as a specific voebuditel of B. of l. According to the last concept of B. of l. develops at persons with already available hron, proliferation of limfoidnogistiotsitarny fabric. Malaria can be the cause of such proliferation, geographical distribution a cut in Africa matches the territory of «a limfomny belt». In the absence of an initial limfoproliferation Epstein's virus — Burra causes only subclinical display of an infection with positive serological tests and occasionally — an infectious mononucleosis.
B. of l is macroscopic. it is characterized by existence of the numerous tumoral nodes reaching sometimes the huge sizes. The tumor has destructive growth. Superficial nodes often ulcerate owing to germination of a tumor in surrounding fabrics. According to section data, tumoral defeats are localized in the following bodies and fabrics (as the decreasing frequency): kidneys, ovaries, retroperitoneal limf, nodes, jaws, adrenal gland, pancreas, liver, thyroid gland, spleen, small bowel, stomach etc. Practically such localizations, characteristic of other lymphoma, as peripheral and mediastinal limf, nodes, a thymus and a limfoidnoglotochny ring are not observed (valdeyerovo a ring). Histologically B. of l. it can be carried to group of the low-differentiated (lymphoblastoid) lymphosarcomas. The basic cellular element of a tumor is the unripe lymphoid cell (lymphoblast) with fine-grained distribution of chromatin in the kernel having the round, oval or irregular form. Such structure of a kernel allows to distinguish B.'s lymphoblasts of l. from similar cells of other lymphosarcomas. During the coloring hematoxylin-eosine in cells comes to light a narrow amfofilny rim of cytoplasm, the rich RNA containing fatty vacuoles. The large vacuolated histiocytes having phagocytal activity occur among lymphoid cells; this combination is described as a picture of «star sky». Kernels of lymphoblasts and histiocytes have the identical sizes. On cytologic drugs (smears, prints) the anisocytosis of lymphoblasts clearly is swept up (diameter from 10 to 25 microns); cells contain 2 — 5 small kernels, basphilic cytoplasm is deprived of granularity. In cytoplasm of a part of lymphoid cells of a tsitokhimicheska find PAS positive granules, in many cells — granules of lipids. The histiocytes lying among lymphoblasts are rich with neutral fat, acid phosphatase and nonspecific esterase. Cells of a tumor have high mitotic activity.
In an elektronnomikroskopichesky picture the most characteristic sign of B. of l. consider protrusions in cytoplasm of the sites of a kernel containing chromatin. According to some authors, through these protrusions the virus which is originally localized in a kernel after the maturing leaves in cytoplasm.
Cytogenetic analysis of cells of B. of l., subjected to cultivation, finds an aneuploidy (see. Chromosomal complement ) and various changes of number and hyperdispersion of chromosomes which in each case have individual character. Find marker in a part of patients chromosomes (see). Any fundamental kariologichesky differences between B. of l. and other tumors do not note.
The clinical picture
the Disease begins sharply, with emergence of a tumoral node in one of the listed above areas. Process is inclined to bystry generalization, in particular on abdominal organs. At girls bilateral tumors of ovaries are especially often observed. Rapid growth of tumors is followed by emergence of various compression symptoms (e.g., a hydronephrosis at defeat retroperitoneal limf, nodes). Tumoral growths in covers or substance back and a brain, causing various neurologic symptomatology (e.g., the lower paraplegia are especially dangerous at a prelum of a spinal cord etc.).
Radiological bone defeats have an appearance of the small sites of depression further merging in the large centers of ossifluence in the beginning. At localization of a tumor in jaws destruction of the cortical closing plates around teeth and their rudiments is characteristic. The picture of blood is usually not changed. At extensive infiltration of marrow in blood the leukocytosis and normoblastoz, occasionally — a small number of tumor cells can be observed. B.'s cases of h.p. are described by development of a picture of an acute lymphoblastoid leukosis. In uncured cases the disease quickly progresses also in several weeks or months inevitably comes to an end with death. Depending on degree of prevalence of a disease by the time of primary medical examination it is offered to distinguish the following clinical stages of B. of l.: 1 — defeat of one anatomic area; 2 — defeat of two adjacent areas; 2-6 — defeat more than two areas on one side of a diaphragm; 3 — defeats on both sides of a diaphragm, but without involvement of c. N of page; 4 — a disease with defeat of c. the N of page
the Diagnosis in local zones is simple. It is based on detection at the child of a fast-growing tumor of jawbones or in an abdominal cavity, at a histologic research a cut establish a picture of «star sky». Finally confirms the diagnosis positive reaction of an immunofluorescence between a suspension of tumor cells and blood serum of obviously sick B. of l. Recognition of a disease in those countries where B. of l is much more difficult. meets incidentally. In these cases as the main diagnostic criterion serve serological tests.
The differential diagnosis is carried out with nek-ry diseases from group of malignant lymphoma (see. Lymphoma ).
At an acute lymphoblastoid leukosis there are characteristic changes of blood and marrow; cells of tumoral nodes differ in a large number of PAS positive granules, their kernel there are less kernels of surrounding histiocytes and differ in more gentle chromatin and less noticeable small kernels. At a reticulosarcoma of a cell with more extensive cytoplasm; kernels with polymorphism, the large sizes, with rough structure of the chromatin containing large kernels. It is the most difficult to differentiate B. of h.p. a lymphoblastoid lymphosarcoma. In addition to negative serological tests, this tumor differs from B. in l. nek-ry cytologic signs: a kernel of tumor cells there are less kernels of histiocytes, differ in a variety of size and a form, more rough chromatin.
Forecast in uncured cases adverse. On condition of timely therapy perhaps absolute recovery.
B. of l. it is highly sensitive to different types of cytostatic medicinal therapy. The best results are received at treatment by Cyclophosphanum which is applied intravenously (in a dose of 30 — 40 mg/kg) once or, in case of need, repeatedly (in 10 — 14 days). In cases of early diagnosing of B. of l. happens one injection enough. From other alkylating drugs apply Embichinum intravenously (in a dose of 0,2 — 0,3 mg/kg a day) 4 — 5 days in a row; repeated courses — in 3 — 4 weeks. This drug can be replaced with Novembichinum. Positive takes are yielded also by use of Melphalanum and other options of sarcolysine which are more effective, than Cyclophosphanum. Drugs of sarcolysine are used in high doses (1 — 2 mg/kg) once or repeatedly with big intervals. The Bystry, but short-term effect is gained from Vincristinum (0,07 mg/kg of 1 — 2 time with a break of 2 — 3 weeks). At distribution of process on covers and substance back and a brain enter a methotrexate intralyumbalno (in a dose of 5 mg with further increase).
In opportunities treatment is followed by bystry reduction of the sizes of tumoral nodes. Efficiency of therapy is in a feedforward with a clinical stage of a disease: at the 1st and 2nd stages it is much higher, than at the 3rd and 4th. From 245 patients, according to aggregated data, at 38 (15%) full remission without the supporting treatment lasts from 1 to 7 years. It is considered that if full remission continues more than 1 year, then the recurrence will not come any more and the patient is cured. Such high performance of chemotherapy at B. of l. is explained by the expressed immunological defense reaction of an organism of patients.
Other methods of treatment are of secondary importance. Active immunization by the irradiated autologous cells, passive immunization by serum of patients with high immunological activity or nonspecific immunization with BTsZh and other bacterial vaccines, according to some authors, can improve results of medicinal treatment. Surgical intervention at tumors of jaws is contraindicated in view of rich vascularization of B. of l. and dangers of bleedings. Radiation therapy can give local antineoplastic and analgesic effect.
Prevention it is not developed.
Bibliography: Avtsyn A. P., A. A. and Kazantsev's Larks I. A. Sarkoma Burkitta in the light of data of cytopathology, Vestn. USSR Academy of Medical Sciences, Λβ 6, page 13, 1969; Vorobyov Yu. I., etc. Experience of beam treatment of a tumor of Berkitt, Vopr, onkol., No. 3, page 34, 1970; In u of with h e-
p and 1 J. N of Long-term survival in Burkitt's tumor and in acute leukemia, Cancer Res., v. 27, p. 2616, 1967; Burkitt D. P. Etiology of Burkitt’s lymphoma — an alternative hypothesis of a vectored virus, J. nat. Cancer Inst., v. 42, p. 19, 1969; B u r k i t t D. P. a. D a v i e s J. N. P. Lymphoma syndrome in Uganda and tropical Africa, Med. Press, v. 245, p. 367, 1961; Clifford P. o. Long-term survival of patients with Burkitt's lymphoma, Cancer Res., v. 27, p. 2578, 1967, bibliogr.; Epstein M. A. a. A with h ο n g B. G. Observations on the nature of herpes-type EB virus in cultured Burkitt lymphoblasts, using a specific immunofluorescence test, J. nat. Cancer Inst., v. 40, p. 609, 1968, bibliogr.
Yu. I. Loriye.