Lymphoma, including Hodgkin's disease.

Hodgkin's Lymphoma is primarily a disease of cells which make-up the lymphatic system. Its cellular characteristic is the presence of Reed Sternberg cells with double nuclei. Lymphadenopathy is the particular manifestation. It is distinguished macroscopically from the other lymphomas by predominantly involvement of adjacent or contiguous glands. Lymphomas may be sub-divided microscopically by the predominance of the stromal or lymphocytic components (with or without surface markers).

If we assume that the effect of genes, viruses and environmental factors randomly determine that lymphoma would start anywhere, simple probability would determine that a random process, is more likely to be sited in a large collection of cells. The expression of a proliferative process in the lungs depends on the predominant distribution of lymphoid tissue of which the majority lies in the mediastinum. Smaller juxta-hilar bronchial glands are present in both lungs. The lung contains smaller collections of cells in the sub-mucosa of the bronchial tree, or in the interlobular septa, the walls of the basic pulmonary unit.

If the disease becomes more extensive, assuming no effect from the characteristics of neighbouring tissue, it will be possible to see collections of lymphoid tissue that are too small to be seen on the normal radiograph. Given that Hodgkins disease is characteristically localized to adjacent lymphoid tissues, the probability of visible involvement would be para-tracheal glands, followed by; bronchial glands, and then sub-mucosal lymph tissue in the bronchi (bronchial mucosa associated lymphoid tissue, BALT and concentrated at the divisions of bronchioles ) or lymphoid collections in the interlobular septa, and the occasional lymphoid cells in the lung parenchyma in descending order of size of tissue and visibility. This would explain the observation that an air bronchogram is not a feature of direct lung involvement by lymphoma, where sub-mucosal collections of abnormal tissue might reduce bronchial air flow.

The anatomy also explains the peripheral post-radiotherapy recurrence of lymphoma, away from the irradiated, more central collections of lymphoid tissue.

Given that the presence of lymphoma and its current treatment may affect immune system performance, it should always be considered that a diffuse pulmonary pattern may indicate an additional infection.

STAGING

• stage I
• Involvement of one lymph node group.
• One disease focus.
• stage II
• More than one lymph node group on same side of diaphragm.
• One disease focus plus lymph node group(s) on same side of diaphragm.
• stage III
• Lymph node (+ - spleen) involvement on both sides of the diaphragm.
• One localised disease focus with separate lymph node involvement and resulting in disease on both sides of the diaphragm.
• stage IV
• More than one (non- nodal) disease focus.
• Multiple involvement of nodes and organs.
• substages
• A - Absence of physical symptoms.
• B - Presence of physical symptoms, Night sweats, malaise.

See also: