From the archives of the AFIP: primary peritoneal tumors: imaging features with pathologic correlation

Extraovarian primary peritoneal carcinoma: staging with 18F-FDG PET/CT

A 69-year-old woman who presented with left lower quadrant abdominal pain and elevated serum cancer antigen 125 (CA-125) levels was referred for an MRI and an (18)F-FDG PET/CT to evaluate a suspicious abdominal mass seen on ultrasound. PET/CT showed extensive, intensely FDG-avid, omental and pelvic peritoneal thickening with no suspicious ovarian or colon masses. Based on the PET/CT results, the patient had extensive debulking surgery and histopathological evaluation revealed an extraovarian primary peritoneal carcinoma (EOPPC). (18)F-FDG PET/CT may be useful in differentiating EOPPC from other types of peritoneal carcinomatosis, and in determining the extent of the disease to better guide surgical management and improve long term outcomes.

Infiltrating lobular carcinoma of the breast presenting as gastrointestinal obstruction: a mini review

One in twelve American women will develop breast cancer, with infiltrating lobular carcinoma (ILC) comprising approximately 15% of these cases. The incidence of ILC has been increasing over the last several decades. It has been hypothesized that this increase is associated with combined replacement hormonal therapy. Although pathologically distinct from infiltrating ductal carcinoma (IDC), ILC is treated in the same manner as IDC. However, ILC demonstrates significantly different patterns of late local recurrence and distant metastasis. The incidence of extra-hepatic gastrointestinal metastases is reported to be 6% to 18%, with stomach being most common. Herein, we present a brief review of the literature and a typical case involving ILC initially presenting as a small bowel obstruction. Evidence suggests that the late clinical patterns of ILC are distinctly separate from IDC and physicians need be cognizant of its late local recurrence and unique late metastatic pattern. Different follow up strategy should be entertained in patients with ILC.

Mesenteric tumors: diagnosis and treatment

Mesenteric tumors are rare and consist of a heterogeneous group of lesions. Masses may arise from any of the mesenteric components: peritoneum, lymphatic tissue, fat, and connective tissue. Cellular proliferation can also arise from infectious or inflammatory processes. They can be classified as solid or cystic, benign or malignant. Mesenteric tumors are usually discovered incidentally or during investigation of non-specific symptoms. While clinical examination and imagery may suffice to make the diagnosis, histopathology is often required by either needle percutaneous or surgical biopsy, or immediate excision. Therapeutic management options vary widely depending on the nature of the lesion; they range from simple observation or medical therapy to surgery. Benign well-delineated mesenteric masses that are symptomatic can often be treated by simple enucleation. But invasive malignant tumors require a carcinologic resection; a careful preoperative evaluation to assess the relationship between the mass and adjacent vascular and digestive structures is essential since they may dictate the need for extensive sacrifice of bowel with resultant intestinal insufficiency due to short bowel syndrome.

Epithelioid Lesions of the Serosa

Context.—Diagnosing epithelioid serosal lesions remains a challenge because numerous different processes—primary or secondary, benign or malignant—occur in body cavities, some of which are very rare.

Objectives.—To review the newest literature and to describe the morphologic criteria and immunohistochemical markers that are useful for distinguishing epithelioid serosal lesions.

Data Sources.—Previously published literature concentrating on the newest research findings. Earlier reviews are principally referred to for established diagnostic criteria.

Conclusions.—Immunohistochemistry with a panel of antibodies has made the diagnosis of epithelioid serosal lesions very reliable. When deciding on antibodies used in differential diagnosis, it is important to consider tumor location, clinical and radiologic information, and morphologic features. Immunohistochemistry is less useful in the differential diagnosis of benign versus malignant mesothelial lesions. The diagnosis of benign versus malignant mesothelial proliferations still relies on the histologic criteria of invasion.

CT appearance of primary peritoneal serous borderline tumour: a rare epithelial tumour of the peritoneum

Primary peritoneal serous borderline tumour (PPSBT) is a rare epithelial neoplasm which is histologically identical to serous borderline tumour of the ovary. PPSBT is distinguishable from primary peritoneal serous carcinoma because the tumour cells do not invade the underlying tissue and affected patients have a good prognosis. We report the CT findings of surgically proven PPSBT in which multiple peritoneal cysts were seen. Although rare, PPSBT should be considered in the differential diagnosis of primary peritoneal tumours. Since the prognosis of the disease is good, conservation of the uterus and ovaries should be a consideration in young female patients during surgery.

Diffuse malignant peritoneal mesothelioma--an update on treatment

Mesotheliomas are aggressive and lethal neoplasms arising from mesothelial cells lining the pleura, peritoneum, tunica vaginalis testis and pericardium. Malignant peritoneal mesothelioma accounts for about 30% of all mesotheliomas. Asbestos is the main known cause of the disease. Presenting symptoms in these patients include: ascites, abdominal pain, asthenia, weight loss, anorexia, abdominal mass, fever, diarrhea and vomiting. Electron microscopy, immunohistochemistry, computed tomography scan, echotomography, magnetic resonance imaging, positron emission tomography and laparoscopy are used in diagnosis and follow-up. Chemotherapy alone is considered as a palliative treatment for these patients who are not eligible for radical surgery. The most promising non-surgical approach today in the management of peritoneal mesothelioma is the use of the combination chemotherapy regime of an antifolate (pemetrexed and raltitrexed) and a platinum based (cisplatin) agent with a median survival of about 12-14 months. Due to peritoneal confinement of malignant mesothelioma and low occurrence of metastasis, a locoregional approach consisting of cytoreductive surgery and perioperative intraperitoneal chemotherapy has been introduced as a curative treatment option over the last decade with an overall 5-year survival rate of 29-63%. In this locoregional approach, surgery can separate the adhesions and remove the bulky tumor, leaving microscopic residual tumors much more susceptible to the killing effect of chemotherapeutic drugs. Here in St. George hospital, cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (using cisplatin and doxorubicin) resulted in significant survival advantage. This article describes how the prognosis of the disease has changed over the last decade.

Adenocarcinoma in an intrapancreatic accessory spleen: report of a case

We report a case of adenocarcinoma in an intrapancreatic accessory spleen (IPAS). A 78-year-old woman presented with abdominal discomfort, and investigations revealed an elevated serum carbohydrate antigen 19-9 level, to 161.8 U/ml (normal, <37 U/ml). Ultrasonography showed a heterogeneous echogenic tumor with a vascular hilum. Computed tomography showed a heterogeneously enhanced tumor, 8 cm in diameter, adjacent to the pancreatic body, accompanying a feeding artery arising from the splenic artery, and a drainage vein flowing into the splenic vein. We performed a distal pancreaticosplenectomy. The tumor was surrounded by a fibrous capsule and was in contact with the pancreatic body. Histological examinations revealed invasive growth of adenocarcinoma in a structure identical to the spleen. The results of both radiological and histological examinations suggested that the tumor originated from an intrapancreatic accessory spleen. Extensive examinations revealed no other malignancy, based on which we concluded that the adenocarcinoma was primary. Surgical intervention is strongly recommended when a malignancy in an IPAS cannot be ruled out.

CT, MRI and PET imaging in peritoneal malignancy

Imaging plays a vital role in the evaluation of patients with suspected or proven peritoneal malignancy. Nevertheless, despite significant advances in imaging technology and protocols, assessment of peritoneal pathology remains challenging. The combination of complex peritoneal anatomy, an extensive surface area that may host tumour deposits and the considerable overlap of imaging appearances of various peritoneal diseases often makes interpretation difficult. Contrast-enhanced multidetector computed tomography (MDCT) remains the most versatile tool in the imaging of peritoneal malignancy. However, conventional and emerging magnetic resonance imaging (MRI) and positron emission tomography (PET)/CT techniques offer significant advantages over MDCT in detection and surveillance. This article reviews established and new techniques in CT, MRI and PET imaging in both primary and secondary peritoneal malignancies and provides an overview of peritoneal anatomy, function and modes of disease dissemination with illustration of common sites and imaging features of peritoneal malignancy.

Benign cystic mesothelioma: a case series with one case complicated by pregnancy

Benign cystic mesothelioma (BCM) is a rare tumor of unknown origin, most frequently encountered in women of reproductive age and with unknown etiology. Most patients have a history of previous pelvic operation, endometriosis, or pelvic inflammatory disease. Preoperative diagnosis is difficult. We report the cases of three patients, with one case complicated by pregnancy, and discuss the diagnostic evaluation and treatment of this rare disease. Complete surgical resection is recommended if feasible. However, recurrent disease is not uncommon. Clinical positive effects of different adjuvant medical treatments are also discussed.

Tumors and pseudotumors of the secondary müllerian system: review with emphasis on cross-sectional imaging findings

OBJECTIVE

Microscopic structures lined by müllerian epithelium are frequently seen outside the uterus and fallopian tubes and are termed "müllerian rests" or "secondary müllerian system." Varied entities ranging from benign endosalpingosis to highly malignant ovarian tumors are thought to be derived from the secondary müllerian system. Cross-sectional imaging findings of diseases and disorders of the secondary müllerian system are presented here.

CONCLUSION

Familiarity with a wide spectrum of diseases and disorders of the secondary müllerian system allows accurate diagnosis and management.

Benign multicystic peritoneal mesothelioma: a case report

INTRODUCTION

We report the case of a patient with a benign multicystic peritoneal mesothelioma and describe its appearance on computed tomography scans and ultrasonography, in correlation with gross clinical and pathological findings.

CASE PRESENTATION

A 72-year-old Caucasian woman presented to our emergency department with acute abdomen signs and symptoms. A clinical examination revealed a painful palpable mass in her left abdomen. Abdominal ultrasonography and computed tomography demonstrated the presence of a large cystic mass in her left upper abdomen, adjacent to her left hemidiaphragm. The lower border of the mass extended to the upper margin of her pelvis. A complete resection of the lesion was performed. Pathological analysis showed a benign multicystic peritoneal mesothelioma.

CONCLUSIONS

Benign multicystic peritoneal mesothelioma is a rare lesion with a non-specific appearance on imaging. Its diagnosis always requires pathological analysis.

Cytomorphologic characteristics of fine needle core biopsy of multicystic peritoneal mesothelioma: a case report and review of the literature

Multicystic peritoneal mesothelioma (MPM) is an uncommon cystic mesothelial proliferative lesion. It occurs predominantly in women of reproductive age and most commonly arises in the pelvis. The preoperative diagnosis of MPM is difficult to establish based on clinical and radiographic findings, and has therefore traditionally been diagnosed following surgical resection. Due to differing management of MPM and its differential diagnoses including both benign and malignant lesions, it would be beneficial to diagnose MPM preoperatively. We report a case of MPM in a middle aged female that was diagnosed by fine needle core biopsy and touch preparations, allowing for appropriate clinical management. The cytomorphologic features of needle core biopsy, immunocytochemical studies and differential diagnosis are discussed. Furthermore, despite its infrequency, the current case emphasizes the importance of the inclusion of this entity in the differential diagnosis of cystic lesions of the abdomen and pelvis at the time of on-site evaluation and final diagnosis, in order to avoid misinterpretation of strips of benign mesothelial cells as inadequate for diagnosis.

Diffuse malignant peritoneal mesothelioma presenting as intestinal obstruction

Diffuse malignant peritoneal mesothelioma (DMPM) represents 90% of all peritoneal forms of mesothelioma. It affects mainly patients 50-69 years old. In 50% of cases there is a history of asbestos exposure. The clinical presentation of the disease is not characteristic: nonspecific abdominal pain, weight loss, and abdominal distension are common. Ascites occurs in 90% of the patients. Bowel obstruction is a late manifestation. We present three patients with DMPM, without a history of asbestos exposure and without ascites, who presented with complete bowel obstruction. All patients underwent emergency operations, and palliative surgical procedures were performed. Each patient died within 3 to 6 months postoperatively.

Secondary tumors and tumorlike lesions of the peritoneal cavity: imaging features with pathologic correlation

Tumors and tumorlike lesions that secondarily involve the mesothelial or submesothelial layers of the peritoneum are a diverse group of disorders that range in biologic behavior from benign to highly malignant. The anatomy of peritoneal ligaments and mesenteries and the normal circulation of peritoneal fluid dictate location and distribution of these diseases within the peritoneal cavity. Peritoneal carcinomatosis is the most common secondary tumor to affect the peritoneal cavity. When it arises from carcinomas of the gastrointestinal tract or ovary, the prognosis is grave. However, when low-grade mucinous adenocarcinoma of the appendix spreads to the peritoneal cavity, the consequence is typically pseudomyxoma peritonei, which is a clinical syndrome, characterized by recurrent and recalcitrant voluminous mucinous ascites due to surface growth on the peritoneum without significant invasion of underlying tissues. Carcinomas from elsewhere in the body, as well as lymphomas and sarcomas, may also produce diffuse peritoneal metastasis. Granulomatous peritonitis is the consequence of disseminated infection such as tuberculosis or histoplasmosis, foreign materials, or rupture of a tumor or hollow viscus. Finally, a group of benign miscellaneous conditions that range from common disorders such as endometriosis and splenosis to very rare conditions such as gliomatosis peritonei and melanosis may also affect the peritoneum diffusely. Secondary tumors and tumorlike lesions of the peritoneum have overlapping imaging features when compared with each other and primary peritoneal tumors. Knowledge of peritoneal anatomy, normal fluid circulation within the peritoneal cavity, and clinical and pathologic features of secondary peritoneal lesions is essential for identification of these lesions.

Ovarian cancer: detection and radiologic staging

Ovarian cancer is the second most common gynecologic malignancy. It is the deadliest, largely owing to late stage at the time of diagnosis. Ultrasound is modality of choice in the evaluation of suspected adnexal masses. Magnetic resonance imaging is an excellent problem solver when an adnexal mass is indeterminate on ultrasound. Staging of ovarian cancer remains surgical, though preoperative imaging can identify inoperable patients and identify suspicious sites for intraoperative biopsy. This article reviews the use of different imaging modalities in the detection and staging of ovarian carcinoma, and discusses imaging indications, radiologic features, and the shortcomings of imaging.