Introduction
Primary hepatic angiosarcoma (PHA) is a rare case of a liver tumor. However, it is also the most common malignant mesenchymal cell tumor of the liver. PHA is commonly found to occur after 60 to 70 years of age. Its diagnosis poses a serious challenge for doctors owing to its high resemblance to other liver diseases. Another reason for this is the lack of data and investigation results on clinical manifestations of the disease. As a result, misdiagnosis or a delayed diagnosis of the disease is inevitable. There is an increased likelihood of men suffering from this liver malignancy compared to women, with a male-to-female ratio of 4:1. PHA has unique histological features, making its histopathology one of the mainstays for obtaining a definitive diagnosis. PHA is made up of polyhedral, occasionally spindle-shaped, pleomorphic atypical mesenchymal cells. The tumor presents with varied anastomosing vascular channels that do not follow an organized pattern. Certain areas involving necrosis, hemorrhage, and calcification are also exhibited by the tumor in 80 percent of cases. Pathologically, PHA is identified as a large mass with the presence of multiple nodules. The color of the tumor is seemingly whitish-grayish, complemented with an ill-defined border. This article aims to discuss further the symptoms and possible treatment approaches for primary hepatic angiosarcoma.
What Causes Primary Hepatic Angiosarcoma?
No definite factors have been proposed to determine the occurrence of PHA. Possible causative agents include vinyl chloride exposure through prolonged use of plastic bags and other materials. Other proposed carcinogens include arsenic androgen, administration of anabolic steroids, cyclophosphamide, phenelzine, and copper. In the last ten years, the use of thorotrast in angiography has been associated with PHA, with an average latency time of 20 years between exposure and onset.
What Are the Symptoms of Primary Hepatic Angiosarcoma?
There is a marked inconsistency observed in the clinical presentation of the PHA. In some cases, the tumor is presented as completely asymptomatic, making the diagnosis of PHA a significant difficulty. The initial symptoms exhibited closely mimic other chronic liver diseases that often result in a misdiagnosis of the condition. These symptoms include abdominal pain, generalized fatigue, weight loss, signs of jaundice, and anorexia. A physical assessment shows an enlarged liver, with the possibility of ascites or jaundice. About 27 percent of PHA cases present with a tumor rupture followed by hemoperitoneum (bleeding into the peritoneal cavity). Acute liver failure has also been reported in several cases associated with PHA.
How Is Primary Hepatic Angiosarcoma Diagnosed?
The diagnosis of PHA is a problem to combat, with researchers finding various approaches to form a prompt and timely diagnosis of the disease for a better prognosis. There is a significant lack of clinical manifestations and relevant symptoms observed in patients suffering from PHA. Many cases go unnoticed due to the asymptomatic nature of the tumor. Hence, diagnosis completely relies upon radiological imaging tests and histopathological markers.
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The conventional ultrasound does not prove to be of much benefit in cases of PHA. The sound waves traveling through the tumor exhibit different echogenicity owing to the different parts of the tumor, indicating necrosis or hemorrhage.
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Computed tomography (CT) and magnetic resonance imaging (MRI) show similar results, indicating heterogeneous enhancement of the tumor. This is highly suggestive of central necrosis, hemorrhage, or associated fibrotic change.
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Investigation tests include undergoing a liver function test. The increased level of ALP (Alkaline phosphatase) is the most common abnormal finding. A disease that has progressed into much more advanced stages may show signs of hyperbilirubinemia. Thrombocytopenia (reduced platelet count) is observed in approximately 54 percent of PHA patients.
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Angiography is another diagnostic tool that indicates numerous mass lesions that progressively increase over time.
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Histopathological markers obtained secondary to liver biopsy aid multifolds in forming a definitive diagnosis. The four main pathological characteristics of PHA include multiple nodules, the presence of a large dominant mass, the presence of both mass and nodule, and a diffusely infiltrating tumor consisting of several micronodules. Being an extremely vascular tumor, the liver biopsy may often result in hemorrhage. However, this complication can be better controlled with the help of blood transfusion or hepatic arterial angioembolization.
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There are no significant immunochemistry markers observed apart from ERG expression, CD34, CD31, and Factor VIII.
Radiological imaging tests and histopathological findings become the main pathways for obtaining a definitive diagnosis of PHA. The lack of clinical manifestations and insufficient laboratory-specific tests make diagnosing PHA quite a serious dilemma for clinicians. The prognosis for PHA is, by default, poor. To top it off, a delayed diagnosis just adds more to the problem. Therefore, diagnosis of PHA becomes essential to design the best possible treatment plan that can provide a relatively better prognosis.
How Is Primary Hepatic Angiosarcoma Treated?
There exists a significant lack of therapeutic approaches to treat PHA effectively. In the majority of cases, the disease is diagnosed at a much later stage in life. Not much improvement can be obtained in spite of opting for the best treatment modality. To be blunt, the prognosis of PHA is not very accurate. The varied treatment options available include:
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Surgical resection of the tumor is by far the most efficient approach to treat PHA. With advancing technology and medical science, the previous two decades have shown a significant decrease in the mortality rate of patients with PHA.
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For patients for whom surgical treatment is not viable, chemotherapy becomes the next best approach to treat PHA. An improvement in the survival rate of 50 percent of patients has been reported with the administration of chemotherapy.
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Transcatheter intervention therapy and transarterial chemoembolization (TACE) are other treatment modalities that have proven remarkable benefits associated with treating PHA.
Conclusion
The prognosis for PHA is highly debatable. Survival time upon diagnosis of the tumor, is about 1 to 6 months without undergoing any treatment. Surgical resection may increase the time to about 17 months. However, more than 80 percent of PHA cases are not deemed fit for surgical treatment owing to the extremely delayed diagnosis. The most common reasons for death are acute liver failure, or ruptured tumor leading to fatal hemoperitoneum.
