What is Extracranial Lesions?
Extracostal cerebral lesions in acute leukemia in most cases are associated with the form of the tumor process: lymph nodes with their significant increase are usually found in children with acute lymphoblastic leukemia, less commonly found in the same form of leukemia in adults, almost not in other forms of acute leukemia. However, the above features are specific to the first attack, namely, acute leukemia.
The histological picture of such lesions shows either a diffuse proliferation of blast cells or the presence of large foci, both externally and histologically, corresponding to sarcoma metastases (N. A. Kraevsky). Quite often, the first symptom of acute leukemia is extracostal cerebral focal sarcoma growth. Examining a removed tumor allows you to diagnose sarcoma.
The most characteristic extra-cerebral foci of leukemic infiltration are lymph nodes, liver, meninges, skin, spleen, testicles, lungs, kidneys. The most difficult to diagnose and treat are lesions of the gastrointestinal tract.
Pathogenesis during Extracranial Lesions
Metastasis to the meninges, brain substance and nerve trunks can complicate the course of any hemoblastosis, but more often it occurs in children with acute lymph regional leukemia. No major differences have been noted so far in the course of neuroleukemia with different leukemias and in its response to treatment.
In recent years, according to the pathoanatomical data, the incidence of neuroleukemia in children with acute lymphoblastic leukemia has increased significantly, is approximately 75%. According to clinical data, in groups of children who did not receive specific prophylaxis, the frequency of neuroleukemia is about 65%. Most often, neuroleukemia occurs in young children under 15 years of age. The metastatic nature of neuroleukemia was proved by direct methods of chromosomal analysis by Mastrangelo and co-authors back in 1970, which revealed the same changes in the chromosome set in the cells of the cerebrospinal fluid as in the bone marrow cells. The entry and fixation of cells in the meninges occurs at the earliest stages of the disease. This is evidenced by the fact that the achievement of improvement during the first 3-4 weeks after the discovery of a child with acute lymph regional leukemia does not prevent the development of neuroleukemia. And an attempt to delay the radical prophylaxis of neuroleukemia against the background of the achieved improvement will lead to its outbreak, while the prophylactic administration of methotrexate into the spinal canal against the background of induction of remission and after it will delay the onset of neuroleukemia.
Symptoms of Extracranial Lesions
Neuroleukemia is usually characterized by meningeal syndrome; at the same time initially there is a headache, and only then nausea and vomiting. The above symptoms often grow slowly, usually taken as random, due to errors in the regime, in the diet. In other cases, without any signs of meningeal syndrome, the child’s behavior changes: it becomes capricious, irritable, sluggish, unsociable. In the study often found stagnation of the fundus of the eye, stiff neck, Kernig symptom, dysfunction of the cranial nerves.
It should be noted that in these cases, spinal puncture already has a high blast cytosis (elevated content of cellular elements) in the fluid.
The above picture refers to the most common form of neuroleukemia, the lesion of the membranes, and intracerebral tumors are much less common. The patient becomes sluggish and complains of a headache. Focal neurological symptoms associated with the localization of the tumor. When intracerebral tumors are observed stagnation of the fundus of the eye, the increase in protein in the cerebrospinal fluid with a normal content of cellular elements – protein-cell disintegration. Pathological focus on the EEG and the offset of the M-echo in the direction opposite to the location of the tumor.
A rather rare debut of neuroleukemia is an isolated lesion of cranial nerves, in particular, oculomotor, auditory, and visual. Neurological symptoms are characterized by double vision, impaired movement of the eyeballs, reduced vision on the affected side, often to complete blindness. As well as developing atrophy of the optic nerve head, noted in the study of the fundus of the eye. It is also possible to damage the facial nerve with flaccid paresis of the facial muscles on the side of the lesion. At the same time, the composition of the cerebrospinal fluid may remain normal, or blast cytosis is found in it, indicating involvement of the brain membranes in the process.
Quite often, the terminal stage of acute leukemia is complicated by radicular syndrome, caused by infiltration of the corresponding roots by leukemic cells, or by compression of the vertebrae as a result of a pathological fracture. Possible and infiltration of the substance of the spinal cord, giving, like a typical spinal tumor, paresis of the legs with conductive disorders of sensitivity and pelvic disorders. In the cerebrospinal fluid at the same time, along with an increase in protein, blast cytosis is not uncommon.