obsolete mesothelial neoplasm

Fibrous Mesothelioma: An Obsolete Term

Fibrous mesothelioma was an outdated term used to describe a solitary fibrous tumor not originating from mesothelial cells [1]. This classification is no longer in use, as it did not refer to sarcomatoid tumors.

Characteristics of Fibrous Mesothelioma

The obsolete term "fibrous mesothelioma" was used to describe a type of tumor that was distinct from other types of mesotheliomas. However, with the advancement of medical knowledge and classification systems, this term is no longer relevant [2].

Current Understanding of Mesothelioma

Mesothelioma is a rare cancer that originates from mesothelial cells lining the pleura or peritoneum. It is characterized by the proliferation of neoplastic mesothelial cells, which can lead to various subtypes, including epithelioid, biphasic, and sarcomatoid [3].

Changes in Classification

The classification of mesothelial tumors has undergone significant changes since 2015. The 2021 World Health Organization (WHO) classification schemata for pleural and pericardial tumors have been updated to reflect the diversity of benign entities and malignant neoplasms originating from the mesothelium [4].

References:

[1] Oct 15, 2024 — Fibrous mesothelioma is an obsolete term used to describe a solitary fibrous tumor not of mesothelial origin. This does not refer to sarcomatoid ...

[2] A neoplasm characterized by the proliferation of neoplastic mesothelial cells. It usually arises from the pleura or peritoneum.

[3] by D Štrbac · 2022 · Cited by 11 — Mesothelioma is a rare tumor, frequently associated with asbestos exposure, arising from pleura and peritoneum. Traditionally, diagnosis and treatment have been ...

[4] The mesothelium of myriad sites shows a common origin from the lateral plate mesoderm; primary mesothelial tumors thus demonstrate similar pathogenesis, imaging findings, and treatment options. Significant changes have been made in the 2021 World Health Organization (WHO) classification schemata of the pleural and pericardial tumors on the ...

Common Signs and Symptoms

Mesothelioma, an obsolete term for malignant mesothelioma, can cause a range of symptoms depending on the location and stage of the disease. Here are some common signs and symptoms:

• Pleural effusion: Fluid buildup in the space around the lungs, leading to shortness of breath and chest pain [1][2]
• Abdominal distension and pain: Swelling and pain in the abdomen, often accompanied by nausea, anorexia, and weight loss [3][4][5]
• Dyspnea and chest wall pain: Difficulty breathing and pain in the chest wall, which can be caused by the pleural effusion or volume contraction associated with mesothelioma [6][7]
• Nonspecific abdominal symptoms: Abdominal pain, fullness, and bloating are common complaints, often leading to delays in presentation due to their nonspecific nature [8][9]

Rare but Possible Symptoms

In rare cases, mesothelioma can also cause:

• Hydrocele (swelling in the scrotum): Fluid collection in the scrotum, which can be a sign of mesothelioma affecting the tunica vaginalis testis [10]
• Lump in the scrotum: A palpable mass in the scrotum, which can indicate mesothelioma of the tunica vaginalis testis [11]

Important Notes

It's essential to note that these symptoms are not unique to mesothelioma and can be caused by other conditions. A proper diagnosis requires a medical professional's evaluation.

References:

[1] Oct 25, 2023 — Mesothelioma can cause fluid to build up in the space around your lungs. [2] Dec 3, 2023 — Signs and Symptoms of Peritoneal mesothelioma · swollen or painful abdomen [3] by D Khosla · 2024 — Symptoms include progressive dyspnea, dry cough, and chest pain. [4] The clinical presentation of peritoneal mesothelioma is generally similar to that of ovarian and PPC i.e., nonspecific abdominal pain, fullness, and bloating, [5] Patients usually present with pleural effusion, dyspnea and chest wall pain. Additional signs and symptoms include chills, sweating, weight loss, and weakness. [6] by S Perdigão · 2024 — Common complaints include abdominal pain with distention, nausea, anorexia, and weight loss. [7] Symptoms are usually nonspecific and occur when disease is advanced, leading to delays in presentation. Pleural mesothelioma presents with gradual onset of symptoms. [8] by K Miklusiak · 2023 — The most common initial symptom is abdominal distension (30–80% of patients) and abdominal pain (27–58% of patients). [9] Symptoms. Signs and symptoms of mesothelioma depend on where the cancer begins. [10] A malignant tumor of the mesothelium is called malignant mesothelioma. [11] Mesothelioma is a rare cancer that’s most commonly found in the lining of the lungs or abdomen, but it can also start in the lining of the heart or testicles in rare cases.

Diagnostic Tests for Obsolete Mesothelial Neoplasms

Mesothelial neoplasms, including diffuse mesothelioma, mesothelioma in situ, and other rare entities such as well-differentiated papillary mesothelial tumor, adenomatoid tumor, peritoneal inclusion cyst, and others, can be challenging to diagnose. Various diagnostic tests have been employed to aid in the diagnosis of these conditions.

Imaging Studies

• CT scans: Can assist in the differential diagnosis of peritoneal mesothelioma with other peritoneal surface malignancies [13].
• MRI: Not commonly used for diagnosing mesothelial neoplasms, but may be useful in assessing tumor extent and planning treatment.

Cytological and Histopathological Examinations

• Pleural fluid cytology: Can be used to diagnose pleural mesothelioma, but often requires more invasive procedures such as closed pleural biopsy [12].
• Closed pleural biopsy: May be adequate for diagnosing pleural mesothelioma, but sometimes requires additional tissue sampling.
• Surgical biopsy: During video-assisted thoracoscopic surgery (VATS) or open thoracotomy, can provide a definitive diagnosis of pleural mesothelioma [15].

Molecular Testing

• Epithelial membrane antigen (EMA): Can be used to differentiate mesothelioma from benign reactive processes [3].
• Silver-stained nucleolar organizer regions (AgNORs) testing: Can aid in the differential diagnosis of mesothelioma and other malignant neoplasms.
• Soluble mesothelin-related peptide (SMRP): Has been suggested as a potential biomarker for diagnosing mesothelioma, but its sensitivity and specificity are still being evaluated [10].

Other Diagnostic Tools

• Karyotypic abnormalities: Can be used to distinguish between mesothelial hyperplasia and malignant mesothelioma [14].
• Tissue diagnosis: Remains the gold standard for diagnosing mesothelioma, as recommended by the British Thoracic Society (BTS) and the American Society of Clinical Oncology (ASCO) guidelines.

It is essential to note that a combination of these diagnostic tests may be necessary to establish an accurate diagnosis of obsolete mesothelial neoplasms.

Treatment Options for Obsolete Mesothelioma

Obsolete mesothelioma, also known as malignant pleural mesothelioma (MPM), is a rare and aggressive cancer that affects the lining of the lungs. While there are no curative treatments available, various drug therapies have been explored to manage this disease.

Chemotherapy-Based Regimens

• Cisplatin-Pemetrexed Doublet: This combination has been a standard chemotherapy-based regimen for MPM since 2004 [1]. Cisplatin and pemetrexed work together to target cancer cells, but their effectiveness can be limited by the development of resistance.
• Platinum Therapy with Pemetrexed and Vitamin Supplementation: This approach remains the mainstay of treatment for surgically unresectable mesothelioma [6]. However, its efficacy is also compromised by the emergence of resistant cancer cells.

Immunotherapy Combination

• Nivolumab/Ipilimumab Combination: In 2020, a combination immunotherapy with ipilimumab and nivolumab was approved as first-line systemic therapy for mesothelioma [3]. This treatment has shown promise in improving overall survival rates, but its effectiveness can vary depending on individual patient factors.

Other Treatment Options

• Bevacizumab: The addition of bevacizumab to pemetrexed plus cisplatin has been shown to improve outcomes in some patients with MPM [14].
• Immunohistochemical Panels: These panels, which include markers such as calretinin and cytokeratin 5/6, can help identify mesothelioma cells in biopsy specimens or cell blocks [15].

Current Treatment Landscape

While these treatment options are available, it's essential to note that the landscape of first-line therapy for advanced mesothelioma has evolved over time. The introduction of new treatments and combinations may offer improved outcomes for some patients.

References:

[1] FDA approval of pemetrexed for mesothelioma treatment [2] Cisplatin-pemetrexed doublet as a standard chemotherapy-based regimen [3] Nivolumab/ipilimumab combination approved as first-line systemic therapy [6] Platinum therapy with pemetrexed and vitamin supplementation [14] Bevacizumab added to pemetrexed plus cisplatin improves outcomes [15] Immunohistochemical panels for identifying mesothelioma cells

The differential diagnosis of an obsolete mesothelial neoplasm, also known as a mesothelioma, involves distinguishing it from other types of tumors that can arise in the pleural, pericardial, or peritoneal cavities.

According to various medical sources [1][3][5], the differential diagnosis of mesothelioma includes:

• Peritoneal carcinomatosis
• Serous peritoneal carcinoma
• Ovarian carcinoma in women
• Lymphomatosis
• Other tumors with a prominent inflammatory component, such as Inflammatory Myofibroblastic Tumor (IMT) and non-neoplastic conditions [5]

In addition, the differential diagnosis of mesothelioma also involves distinguishing it from other types of cancer that can arise in the pleural or peritoneal cavities, such as adenocarcinoma and squamous cell carcinoma [1].

It's worth noting that the differential diagnosis of mesothelioma can be challenging, especially in cases where the tumor is not clearly visible on imaging studies. In such cases, a combination of clinical evaluation, laboratory tests, and histopathological examination may be necessary to establish an accurate diagnosis [3][5].

References:

[1] Kusamura S (2023) - Recent data demonstrated that CT scans could assist in the differential diagnosis of peritoneal mesothelioma with other peritoneal surface malignancies.

[3] Khosla D (2024) - Pleural mesothelioma is a very aggressive malignancy that arises from the pleural mesothelial cell lining and is linked strongly to prior asbestos exposure.

[5] Miklusiak K (2023) - Despite the use of new immunohistochemical and molecular markers, mesothelioma can be misdiagnosed. Therefore, tumors in the abdominal cavity should be thoroughly evaluated for potential differential diagnoses.