Multicystic Mesothelioma: A Benign and Uncommon Condition
Mesothelioma is a rare and aggressive cancer that affects the lining of the lungs, abdomen, and heart. However, not all mesotheliomas are malignant. Some can be benign, such as multicystic mesothelioma. This type of mesothelioma is relatively uncommon and does not have the same serious consequences as the malignant variety. In this article, we will explore multicystic mesothelioma, its presentation, diagnosis, and treatment options.
What is Multicystic Mesothelioma?
Multicystic mesothelioma, also known as benign multicystic mesothelioma or cystic mesothelioma, is a rare benign tumor that arises from the mesothelial lining of the abdominal cavity, pelvis, or, in very rare cases, the tunica vaginalis of the testes. The tumor usually presents as multiple cysts, filled with clear or straw-colored fluid, lined by mesothelial cells. The cysts can be various sizes, from a few millimeters to several centimeters.
Multicystic mesothelioma occurs most commonly in women of reproductive age, although cases have been reported in men, children, and postmenopausal women. The tumor is not associated with asbestos exposure, unlike mesothelioma of the lung or pleura, which is almost always caused by asbestos exposure.
Presentation of Multicystic Mesothelioma
The symptoms of multicystic mesothelioma are non-specific and can mimic other more common conditions, such as ovarian cysts, endometriosis, or uterine fibroids. The most common presenting symptom is abdominal pain, which can be dull or sharp, intermittent or constant, and can be located in the lower abdomen, pelvis, or back. Other symptoms include bloating, nausea, vomiting, constipation, dysuria, and dyspareunia.
On physical examination, a mass or swelling may be palpable in the lower abdomen or pelvis. The mass can be mobile or fixed, soft or hard, and can vary in size depending on the number and size of the cysts.
Diagnosis of Multicystic Mesothelioma
The diagnosis of multicystic mesothelioma can be difficult and requires a combination of radiological imaging, biochemical markers, and histopathology.
Ultrasound, CT scan, or MRI can reveal the presence of multiple cystic lesions in the abdomen or pelvis. However, these imaging modalities cannot differentiate between benign and malignant tumors, and therefore, a biopsy is required to establish the diagnosis.
The most commonly used biochemical marker for mesothelioma is mesothelin, which is a glycoprotein expressed by mesothelial cells. However, the sensitivity and specificity of mesothelin for multicystic mesothelioma are not well established, and false-positive and false-negative results can occur.
Histopathological examination of the cystic fluid and/or the cyst wall is necessary to confirm the diagnosis of multicystic mesothelioma. The characteristic features of the tumor are the presence of multiple cysts lined by a single layer of flat to cuboidal cells with no or minimal atypia, no invasion of adjacent tissues, and no mitotic figures. Immunohistochemistry can be used to confirm the mesothelial origin of the tumor.
Treatment of Multicystic Mesothelioma
The treatment of multicystic mesothelioma depends on the size, location, and symptoms of the tumor. If the tumor is asymptomatic and small, observation may be sufficient, with follow-up imaging and biochemical markers to monitor for any changes. However, if the tumor is large and symptomatic, surgical removal may be necessary.
The surgical approach depends on the location of the tumor. If the tumor is confined to the pelvis, a laparoscopic or open surgical approach can be used to remove the entire tumor. If the tumor involves the peritoneum or other abdominal organs, a more extensive surgical procedure, such as debulking or cytoreduction, may be necessary.
In some cases, chemotherapy or radiation therapy may be used as an adjuvant therapy to surgery. However, the effectiveness of these treatments for multicystic mesothelioma is not well established, and their use is controversial.
Prognosis of Multicystic Mesothelioma
The prognosis of multicystic mesothelioma is generally excellent, with a very low risk of recurrence or metastasis. The mortality rate is almost negligible, and the 5-year survival rate is close to 100%. The majority of patients who undergo surgery for multicystic mesothelioma are cured of their disease.
Conclusion
Multicystic mesothelioma is a rare benign tumor that occurs in the mesothelial lining of the abdominal cavity, pelvis, or testes. The tumor presents as multiple cysts, filled with clear or straw-colored fluid, and can cause abdominal pain, bloating, and other non-specific symptoms. The diagnosis of multicystic mesothelioma requires a combination of radiological imaging, biochemical markers, and histopathology. The treatment of multicystic mesothelioma depends on the size, location, and symptoms of the tumor, and can include surgical removal, chemotherapy, or radiation therapy. The prognosis of multicystic mesothelioma is excellent, with a very low risk of recurrence or metastasis, and a close to 100% 5-year survival rate.