Pathology of lymphatic vessels

Lymphatic vessels are thin vessels lined by the endothelium in which the lymph flows. They are difficult to see macroscopically because they are collapsed. The lymphatic system begins blindly in the tissues and joins into major lymphatic strains. These strains have a thin layer of smooth muscle and valves. Its function is to drain part of the interstitial fluid (tissue fluid). In a pathological condition, infections or tumors can be spread by lymphagenic vessels. Lymphatic vessel diseases include: lymphangiitis, lymphoangiopathy carcinomatosis, lymphedema, lymphorrhage and lymphangiomas.

Lymphangiitis

• It is an acute inflammation of the lymphatic vessels.
• Pyogenic bacteria (β-hemolytic streptococcus) are the most common cause.
• The infection can often spread to regional lymph nodes, from which it can travel to the blood and cause bacteremia or even sepsis.
• Clinical signs: a red, hard and painful stripe under the skin that copies the way of a blood vessel.

Lymphangiopathia carcinomatosa

• It is a significant dilation of small lymphatic vessels by malignant tumor cells.
• It occurs most often in the lungs.
• Lymphatic vessels are macroscopically visible as white branching streaks in the pleura. These streaks are also around the bronchi and branches of the pulmonary artery.
• Clinical signs: severe dyspnoea.

Lymphedema

Lymphedema

• It is the swelling caused by a disorder of lymph drainage.
• It arises from chronic obstruction of lymphatic vessels, which is accompanied by venostasis (mainly on the limbs).
• It can occur secondarily after infection, when the lymphatic vessels become scarred.
• It occur very often in women with breast cancer. Lymphedema occurs as a result of surgical treatment or tumor infiltration of the lymph node or after irradiation.
• In the tropics, it is caused by filarioidea.
• Rarely, it can be caused by congenital malformations of the lymphatic vessels.
• Clinical signs: the limb is heavily swollen, initially pasty in consistency. Later, it is stiffer (due to fiber production) and the skin has an appearance of orange peel. Trophic and inflammatory changes occur on the skin secondly.
• Lymphedema itself is not life-threatening.

Lymphorrhage

• Also lymphorea.
• There is a leakage of milky lymph from the lymphatic vessels.
• It is caused by mechanical damage, tumor obstruction or spontaneous rupture of the ductus thoracicus.
• Lymph can accumulate in the chest and cause chylothorax, or in the abdominal cavity and cause ascites chylosus.

Lymphangioma

Lymphangioma

• Lymphatic vessel tumors.
• They are analogous to hemangiomas but do not contain erythrocytes.
• They are less common and almost always benign.
• They occur mainly in the skin and subcutaneous tissue, in the organs of the abdominal cavity and in the retroperitoneum.
• We distinguish: capillary, cavernous and cystic lymphangiomas.

• • Capillary lymphangioma occurs in the skin and mucosa of the upper small intestine. Chylangioma - capillary lymphangioma in the mucosa of the upper small intestine.
  • Cystic lymphangioma is the only clinically significant one. It arises as a congenital swelling in the subcutaneous tissue of the neck - hygroma colli cysticum. Sometimes it reaches large dimensions - except for the face and the axilla. It grows infiltratively into soft tissues, so it is difficult to resect and often recurs after surgery.

 For more information see Lymphangioma.

Links

Related articles

• Lymphatic system
• Vasculitis
• Development of lymphatic vessels, nodes and spleen

Sources

• POVÝŠIL, Ctibor – ŠTEINER, Ivo – DUŠEK, Pavel, et al. Special pathology. 2. edition. Praha : Galén, 2007. 430 pp. ISBN 978-807262-494-2.