Metastatic peritoneal mesothelioma in the setting of recurrent ascites: A case report

Extraperitoneal parastomal metastasis of malignant peritoneal mesothelioma

A 75-year-old man was referred to surgical outpatient department with what was thought to be a parastomal hernia. Through further investigations with CT and biopsy, it was identified that the parastomal mass was metastatic peritoneal mesothelioma in the abdominal wall and subcutaneous tissue. The patient had a significant surgical history including a previous abdominoperineal resection with end colostomy 9 years prior and a right hemicolectomy for small bowel obstruction the previous year which diagnosed peritoneal mesothelioma. Peritoneal mesothelioma often spreads throughout the abdominal cavity and rarely spreads outside the peritoneum, with this being the first case describing parastomal metastasis. Given the patient's surgical background, this is possible to have contributed to seeding the spread of peritoneal mesothelioma.

Epithelioid malignant mesothelioma metastatic to the skin: A case report and review of the literature

Malignant mesothelioma (MM) is an aggressive and invasive neoplasm primarily affecting the pleura, peritoneum and pericardium. While mesothelioma commonly metastasizes to visceral organs, it has rarely been documented to involve the skin and subcutaneous tissue. There is a paucity of reports of cutaneous metastatic mesothelioma, and histologic examination is often challenging because the tumor closely mimics other primary and metastatic neoplasms. We report a case of a 75-year-old man presenting with a firm, hard nodule on his upper back, which on initial histologic evaluation resembled metastatic adenocarcinoma. However, upon review of his medical history and immunohistochemical evaluation of the lesion, the diagnosis of epithelioid MM metastatic to the skin was rendered. The purpose of this case report and review of the literature is to summarize the most effective available immunostains to aid in the diagnosis of this challenging entity, highlight the histologic similarities between metastatic epithelioid MM and other primary and metastatic neoplasms of the skin, and provide prognostic information for these rare tumors.

Significant Clinical Benefit of Pemetrexed-based Chemotherapy for Advanced Diffuse Malignant Peritoneal Mesothelioma: A Case Presentation

Diffuse malignant peritoneal mesothelioma (DMPM) is generally an understudied disease, largely because most molecular and clinical studies of mesothelioma have been conducted in patients with the more common malignant pleural mesothelioma. We present the case of a 45-year-old male that initially presented with abdominal discomfort and ascites. Diagnostic workup revealed advanced DMPM. Bimodal treatment was stared with cytoreductive surgery and hyperthermic intraperitoneal perfusion with chemotherapy procedure, followed by pemetrexed systemic monotherapy. After the disease progression, and because of a very good previous treatment response to pemetrexed, we decided to rechallenge systemic pemetrexed, along with the introduction of cisplatin. Although the intent behind systemic treatment was at first solely palliative, overall survival after the initial diagnosis was 50 months. Treatment based on rechallenging pemetrexed with or without cisplatin in patients with advanced DMPM can result in a quite satisfactory disease control and symptom management.

[Metastasis revealing malignant peritoneum mesothelioma: About the difficulty to identify the primary tumors]

Peritoneal malignant mesothelioma is a rare and extremely aggressive tumor that is sometimes difficult to diagnose. We report two cases of metastatic malignant peritoneal mesothelioma. In one case, malignant metastatic cells were identified in cervical lymph nodes while in the other case, the cells were found in the liver. In both cases, metastases were identified before discovering the primary tumor. This led to the misdiagnosis of carcinoma of unknown origin. Nevertheless, the histological and immuno-histochemical patterns were typical of malignant mesothelioma. Regarding metastasis of unknown origin, a differentiation of epithelioid peritoneal malignant mesothelioma and adenocarcinoma proved to be difficult. Therefore, we discuss the diagnostic usefulness of immuno-histochemical mesothelioma markers.

Primary Peritoneal Mesothelioma Resulting in Small Bowel Obstruction: A Case Report and Review of Literature

BACKGROUND

Peritoneal mesothelioma is a rare malignancy that affects the serosal surfaces of the peritoneum. The peritoneum is the second most common site of mesothelium affected following the pleura. The aggressive nature and vague presentation pose many obstacles in not only diagnosis but also the treatment of patients with this disease.

CASE REPORT

We present a case of a 76-year-old woman who presented with small bowel obstruction secondary to carcinomatosis secondary to primary peritoneal mesothelioma. The patient had multiple risk factors with asbestos exposure and prior therapeutic radiation.

CONCLUSIONS

We discuss the highly varied and elusive presentation of peritoneal mesothelioma. Cumulative asbestos exposure, either directly or indirectly, remains the leading cause of mesothelioma. However, there are other non-asbestos etiologies. Small bowel obstruction often is a late-presenting symptom of widespread tumor burden. A concise review of the current diagnostic and surgical treatment of primary peritoneal mesothelioma demonstrates that early diagnosis and implementation remains vital.