Angela D. Levy

From the Archives of the AFIP : Primary Peritoneal Tumors: Imaging Features with Pathologic Correlation

Primary peritoneal tumors are uncommon lesions that arise from the mesothelial or submesothelial layers of the peritoneum. Primary malignant mesothelioma, multicystic mesothelioma, primary peritoneal serous carcinoma, leiomyomatosis peritonealis disseminata, and desmoplastic small round cell tumor are the most prominent of these rare lesions. Primary malignant mesothelioma is a highly aggressive malignancy that occurs most commonly in older men and that has a strong association with high levels of asbestos exposure. It manifests most often as diffuse sheetlike or nodular thickening of the peritoneal surfaces, but it may occasionally be a localized mass. Multicystic mesothelioma occurs most frequently in women and has benign or indolent biologic behavior in the majority of patients. It is a multilocular cystic mass that arises from the pelvic peritoneal surfaces. Primary peritoneal serous carcinoma occurs almost exclusively in women. It is histologically identical to ovarian serous carcinoma and may be indistinguishable from metastatic ovarian carcinoma at imaging studies. Leiomyomatosis peritonealis disseminata is a rare, benign proliferative process that also occurs exclusively in women and is characterized by multiple smooth muscle nodules throughout the peritoneum. Desmoplastic small round cell tumor is a highly aggressive malignancy of unknown origin that occurs most often in the peritoneal cavity of young men. This unusual group of tumors is linked together by a common site of origin and imaging manifestations that mimic those of peritoneal carcinomatosis. Knowledge of the spectrum of imaging findings in this group of primary peritoneal tumors, along with their clinical and pathologic characteristics, is important in the evaluation of patients with diffuse peritoneal disease.

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.

Brunner's Gland Hyperplasia and Hamartoma: Imaging Features with Clinicopathologic Correlation

OBJECTIVE The purpose of this essay is to describe, illustrate, and correlate the imaging and pathologic features of Brunners gland hyperplasia and Brunners gland hamartoma. CONCLUSION This article summarizes our experience with pathologically proven cases of Brunners hyperplasia and hamartoma accessioned into the radiologic pathology archive of the Armed Forces Institute of Pathology.

Malignant liver tumors

The primary hepatic malignancies are a diverse group of neoplasms with distinctive clinical and pathologic features. Imaging of the primary hepatic malignancies continues to be challenging. Ultrasonography, CT scanning, and MR imaging play complementary roles in the evaluation of these patients. Many [figure: see text] of these neoplasms have distinctive imaging features that may permit diagnosis. In most instances, however, biopsy is required for definitive diagnosis and treatment planning.

Autopsy radiography: digital radiographs (DR) vs multidetector computed tomography (MDCT) in high-velocity gunshot-wound victims.

This study compared full-body digital radiography (DR) with multidetector computed tomography (MDCT) in the postmortem evaluation of gunshot wound (GSW) victims. Thirteen consecutive male GSW victims (mean age, 27 years) had full-body DR and MDCT prior to routine autopsy. DR successfully identified all metallic fragments, but MDCT was superior in its ability to precisely determine location because it provided 3-dimensional anatomic localization. In all cases, MDCT more accurately assessed organ injuries and wound tracks. Both DR and MDCT are limited in classifying multiple wounds and major vessel injury, but MDCT is generally superior to DR. MDCT shows significant advantages over DR in the forensic evaluation of GSW victims. This is particularly advantageous for the pathologist retrieving metallic fragments and for describing fracture detail accurately. Use of MDCT instead of radiographs will require medical examiners to become familiar with reading cross-sectional images.

MDCT analysis of projectile injury in forensic investigation.

OBJECTIVE This article illustrates the MDCT postmortem imaging features that have the potential to enhance forensic investigation and conventional autopsy. CONCLUSION MDCT may guide, direct, or limit forensic autopsy in projectile injury cases, thereby eliminating the need for a complete invasive autopsy.

Chest Wall Thickness in Military Personnel: Implications for Needle Thoracentesis in Tension Pneumothorax

Needle thoracentesis is an emergency procedure to relieve tension pneumothorax. Published recommendations suggest use of angiocatheters or needles in the 5-cm range for emergency treatment. Multidetector computed tomography scans from 100 virtual autopsy cases were used to determine chest wall thickness in deployed male military personnel. Measurement was made in the second right intercostal space at the midclavicular line. The mean horizontal thickness was 5.36 cm (SD = 1.19 cm) with angled (perpendicular) thickness slightly less with a mean of 4.86 cm (SD 1.10 cm). Thickness was generally greater than previously reported. An 8-cm angiocatheter would have reached the pleural space in 99% of subjects in this series. Recommended procedures for needle thoracentesis to relieve tension pneumothorax should be adapted to reflect use of an angiocatheter or needle of sufficient length.

Multidetector computed tomography findings in deaths with severe burns.

This study compared autopsy with postmortem multidetector computed tomography (MDCT) findings in charred remains. Seventeen consecutive male subjects (mean age, 29.4 years) who perished in a fire-related event resulting in charred remains underwent total body MDCT immediately prior to routine autopsy that included serum carboxyhemoglobin measurement. MDCT showed all thermal tissue changes (skin and subcutaneous fat loss, skeletal muscle retraction, pugilistic attitude, cortical fractures, bone and organ destruction, thermal epidural hematoma, and thermal amputation) and established all fracture patterns that were lethal, but autopsy added the fire as a contributory cause of death when there was carboxyhemoglobin elevation. MDCT had limited value in determination of lethal vascular and visceral injuries. MDCT is an effective complement to autopsy in the setting of charred remains and may serve to augment a limited autopsy. This may be particularly useful in mass casualty scenarios.

Pancreatic Intraductal Papillary Mucinous Neoplasms: Role of CT in Predicting Pathologic Subtypes

OBJECTIVE The objective of our study was to evaluate whether CT can be used to predict the pathologic subtypes of pancreatic intraductal papillary mucinous neoplasms (IPMNs). MATERIALS AND METHODS Three radiologists, blinded to the pathologic IPMN subtype, retrospectively and independently reviewed the preoperative CT scans of 38 patients with surgically resected pancreatic IPMN: 11 intraductal papillary mucinous adenomas, 11 intraductal papillary mucinous carcinomas, and 16 intraductal papillary mucinous carcinomas with invasion. The patients, 16 women and 22 men, ranged in age from 38 to 80 years (mean age, 64.3 years). CT findings were correlated with each pathologic subtype using the chi-square (two-sided) test and analysis of variance. Interobserver agreement of the CT diagnosis of pathologic subtype and agreement between the CT diagnosis and pathologic subtype were also studied (kappa statistic). RESULTS Predominant main pancreatic duct (MPD) involvement (p = 0.04) and a wide (> 1 cm) connection of a side-branch lesion with the MPD (p = 0.03) correlated with intraductal papillary mucinous carcinoma with invasion. Tumor size, MPD diameter, number of tumors per patient, number of pseudoseptations per tumor, common bile duct dilatation, enlarged lymph nodes, intraductal calcifications, papillary bulging, and presence and size of a solid mass yielded no statistically significant relationship with pathologic subtype. Both interobserver agreement of CT diagnosis (range, 0.004-0.359) and agreement between CT diagnosis and pathologic subtype (range, 0.046-0.317) ranged from slight to fair. CONCLUSION Prediction of the pathologic subtypes of pancreatic IPMNs by CT is limited. Predominant MPD involvement and a wide connection of a side-branch lesion with the MPD are the only CT findings that can be used to predict the pathologic subtype of pancreatic IPMN.

Noninvasive imaging approach to patients with suspected hepatobiliary disease.

Technologic advances in ultrasound, computed tomography (CT), and magnetic resonance imaging over the past decade have greatly improved the noninvasive evaluation of the liver and biliary tree. Each imaging modality offers unique and valuable information that aids in the evaluation of the liver and biliary tree. Improved spatial resolution, harmonic imaging, and color and power Doppler have transformed hepatobiliary ultrasound such that it is often the initial examination for many patients. Helical CT permits the characterization of the hepatic parenchyma during multiple phases of contrast enhancement. New rapid magnetic resonance sequences allow images of the liver to be obtained without motion artifact. The multiplanar techniques of magnetic resonance cholangiography allow noninvasive visualization of the biliary and pancreatic ducts. This article reviews the noninvasive imaging approach to patients with suspected hepatobiliary disease.