This disease is an inherited disorder of connective tissue, in which the collagen matrix is affected. Clinical presentation and severity of Marfan syndrome vary widely, ranging from isolated features to neonatal presentation of a severe and rapidly progressing disease involving multiple organ systems.
The disorder has usually been linked to classic ocular, cardiovascular, and skeletal muscle abnormalities. However, manifestations may also include involvement of the lungs, skin, and central nervous system.
Marfan syndrome is caused by a mutation in the gene encoding fibrillin-1 (FBN1), which is inherited in an autosomal dominant fashion. However, isolated cases of recessive mutations in the gene have been reported, and it has been mentioned that 25% of cases are not inherited and correspond to a de novo mutation.
Marfan syndrome conditions
The most severe clinical problems include aortic aneurysm and aortic dissection, the latter being the main cause of mortality in patients with Marfan syndrome. After the introduction of beta-blocker therapy, the implementation of prophylactic aortic surgery and the Losartan trials, the mortality rate caused by this syndrome decreased.
In addition, patients with Marfan syndrome may have deformities of the bone system, including arachnodactyly, dolicostenomelia, pectus deformities, and thoracolumbar scoliosis. Ocular findings include myopia, cataracts, retinal detachment, and upper lens dislocation.
Aspects of interest in the diagnosis of Marfan syndrome
Currently the diagnosis of this disorder in adults is based on Ghent criteria, in which has been compiled the description of cardiovascular, pulmonary, ocular, skeletal, skin and integument complications. However, this diagnosis can be made only after a certain age in the patient.
On the other hand, because Marfan syndrome has been linked to early death in those patients who do not receive treatment, it is essential to get a correct and early diagnosis. Although molecular genetic analysis would be the choice, in some cases this type of study is not available.
Differential diagnosis
During evaluation of a patient suspected of Marfan disease, it is important to consider a differential diagnosis with Loeys-Dietz syndrome and bicuspid aortic valve condition with aneurysm. There is a view that the use of histological and histopathological descriptors may aid the differential diagnosis of Marfan’s disease, of other syndromes involving ascending aortic aneurysms.
In patients with Marfan syndrome, histologic features of the aortic root middle layer include cystic medial necrosis, fibrosis, and loss of smooth muscle cells. Although these histologic findings are not specific to Marfan syndrome, greater elastin fragmentation was observed in patients with the syndrome and aortic root aneurysms compared to those without.
Importance of the tissue processor
Differential diagnosis of Marfan syndrome in other diseases with ascending aortic aneurysm can only be made with a rigorous histopathological analysis. For this, tissue processing is essential.
To study the changes at the cellular and tissue levels, it is necessary to prepare the tissues properly, this means the chemical preservation or fixation of the material, its support in a solid medium, to be able to cut it into very thin sections and stain it.
Tissue processors allow the material to be fixed, dehydrated and placed in a solid medium. In general, the steps for automated tissue processing are:
- Obtaining the tissue sample: careful handling of the sample is required.
- Fixation: usually, formalin is used. This product needs to penetrate all tissue.
- Dehydration: removal of water from the sample by increasing concentrations of ethanol, in order that it can be infiltrated with paraffin. Failure to do so can lead to problems because paraffin is hydrophobic.
- Clarification: since paraffin and ethanol are immiscible, we must eliminate the latter. Xylene is usually used.
- Paraffin infiltration: done at 60 C° with an appropriate histologic paraffin.
- Paraffin block inclusion: the paraffin-infiltrated sample is placed in a paraffin block, allowing the sample to be cut into a microtome.
Kalstein tissue processors
At Kalstein we have a wide range of YR series fabric processors for sale. You will find different models that suit different clinical and forensic diagnostic needs. Kalstein equipment, through the all-in-one design, for dehydration and staining of tissue samples, offer reagent savings and guarantee a large space. In addition, they are designed with an LCD screen that facilitates the configuration and display of the parameters of the process being performed. In addition, they have different protocols for dehydration and tissue staining. For more information on Kalstein fabric processors, visit HERE