High-Grade Lymphomas

There are 3 types of lymphomas in this category: 1) large cell immunoblastic lymphomas; 2) lymphoblastic lymphoma, a tumor that occurs in adolescents and is associated with a characteristic clinical presentation; 3) small noncleaved lymphomas, which include Burkitt's lymphoma and related B-cell neoplasms.

Large Cell Immunoblastic Lymphoma Morphology. In some cases the tumor cells have plasmacytoid features. These cells are four to five times larger than small lymphocytes and have a round or oval large nucleus that appears vesicular owing to margination of chromatin at the nuclear membrane. One or two centrally placed prominent nucleoli are

usually seen. In other cases, the tumor cells may contain large multilobated (polymorphous) nuclei, or the nucleus may be round with a clear cytoplasm. Although features such as plasmacytoid appearance and clear cytoplasm or polymorphous nucleus are suggestive of B- and T-immunoblasts respectively, these distinctions are not absolute.

Lymphoblastic Lymphoma

Morphology. The tumors are fairly uniform in size, with scanty cytoplasm and nuclei that are somewhat larger than those of small lymphocytes. The nuclear chromatin is delicate and finely stippled, and nucleoli are either absent or inconspicuous. In many, but not all, cases the nuclear membrane shows deep subdivision. Imparting a convoluted (lobulated) appearance. In keeping with its aggressive growth, the tumor shows a high rate of mitosis, and as with other tumors having a high mitotic rate (e.g., Burkitt's lymphomas), a «starry sky» pattern is produced by the interspersed benign macrophages.

Small Noncleaved Cell Lymphoma

Morphology. These tumors consist of a sea of strikingly monotonous cells, with round or oval nuclei containing two to five prominent nucleoli. The nuclear size approximates that of benign macrophages within the tumor. There is a moderate amount of faintly basophilic cytoplasm, which also is intensely pyroninophilic and often contains small, lipid-filled vacuoles (better appreciated on stained imprints of the

tumor). A high mitotic index is very characteristic, as is cell death, accounting for the presence of numerous tissue macrophages with ingested nuclear debris. Since these benign macrophages, which are diffusely distributed among the tumor cells, are often surrounded by a clear space, they create a «starry sky» pattern.

HODGKIN'S DISEASE

Lymphogranulomatosis (Hodgkin's disease) is a chronic (in rare cases acute) disease, the growth of the tumor cells takes place mainly in the lymphatic nodes. Morphologically, local and generalized lymphogranulomatosis are distinguished. In isolated lymphogranulomatosis, one group of lymphatic nodes is involved (cervical, mediastinal, retroperitoneal).

In generalized form, the growth of the tumor cells occurs not only in the primary focus but also far from it. As a rule the spleen is involved. Its pulp is red with numerous white-yellow foci of necrosis and sclerosis, so called «difruse waxy spleen». The process becomes generalized due to metastases from the primary node.

Clinico-morphological classification: variant 1: with prevail of lymphoid tissue (lymphohistiocyte); variant; 2: nodular sclerosis variant; 3: mixed-cell variant; 4: with inhibition of lymphoid tissue.

Microscopic study of tumor nodes demonstrates proliferation of lymphocytes, histiocytes, reticulocytes, eosinophils, plasmoblasts and plasmocytes, neutro-

phils. These cells form accumulations of the nodes with necrotic and sclerotic changes. Atypical cells (small Hodgkin's cells, mononuclear giant cells or large Hodgkin's cells) are revealed. The causes of death and complications: 1. Renal amyloidosis followed by contracted kidney and uremia. 2. Intoxication. 3. Septic complications.

Stages of individual work in classStudy and describe macrospecimens

Organ complex in acute leukemia. Pay attention to microfocal hemorrhages on the skin. Describe the ulcerative defects in the esophagus mucosa, hemorrhage in the brain, the packages of the lymph nodes. Explain hemorrhagic diathesis in acute leukemia?

Necrotic quinsy. Pay attention to the appearance of the tonsils, their size and colour. What are the causes of development of necrotic changes on the gastrointestinal tract in acute leukemia?

Bone marrow of the tubular bone in acute leukemia. Pay attention to the replacement of the yellow bone marrow by red one. What is the pathogenesis?

Bone marrow of the femur in chronic lymphocytic leukemia. Pay attention to yellow-green colour of the marrow. How can «pyoid» marrow be explained?

The packages of the lymph nodes in chronic lymphocytic leukemia. Describe the size of the lymph nodes, their appearance on section. Explain the enlargement of the lymph nodes.

Spleen in chronic myelocytic leukemia. The size, colour, condition of the capsule; availability of cicatrices from previous infarctions in it. The cause of the spleen enlargement.

Mesenteric lymph nodes in Hodgkin's disease. Pay attention to the size of the lymph nodes, their color and condition of the tissue on section. Name the stages of Hodgkin's disease.

Spleen in Hodgkin 's disease. Describe the size and colour of the organ on section. How is spleen in Hodgkin's disease called?

Bone marrow of the tubular bone in chronic posthemorrhagic anemia. Pay attention to the replacement of the yellow bone marrow with red bone marrow. What is it connected with. What does the appearance of such marrow remind?