CT features of metastatic linitis plastica to the rectum in patients with peritoneal carcinomatosis

68 Ga-PSMA-11 PET/CT and PET/MRI in Rectal Linitis Plastica Secondary to Prostate Adenocarcinoma

ABSTRACT

Primary or secondary rectal linitis plastica is rare. We describe MRI, 68 Ga-PSMA-11 PET/CT, and PET/MRI findings in a case of rectal linitis plastica secondary to prostate adenocarcinoma. In this case, the rectal linitis plastica was the first manifestation of the prostatic adenocarcinoma, and the rectum was the only metastatic site of the prostate adenocarcinoma. The rectal wall showed circumferential thickening with a concentric ring pattern on MRI, and diffuse intense 68 Ga-PSMA-11 uptake on PET/CT and PET/MRI. Familiarity with the imaging findings of rectal linitis plastica secondary to prostate adenocarcinoma may be helpful for recognition of this rare entity.

Linitis plastica of the rectum secondary to prostate carcinoma

Linitis plastica is an intramural carcinoma that may occur in any hollow organ. Rectal linitis plastica (RLP) is a morphological variant cancer that may occur as a primary form of cancer or secondary as a metastasis of a primary malignancy. We report the case of a man in his 70s with RLP secondary to prostate carcinoma who was initially suspected to have an obstructing rectal adenocarcinoma. During colonoscopy a segment of cobblestone mucosa was seen in the distal rectum. Subsequent imaging showed enhancement of all wall-layers of the rectum and diffuse retroperitoneal fat infiltration with traction on both ureters. A prostate-specific membrane antigen scan confirmed RLP secondary to a prostate carcinoma mimicking the clinical and radiological signs of an obstructing rectal carcinoma with retroperitoneal fibrosis.This case emphasises the possible pitfalls in the diagnosis of RLP and the importance of advanced imaging techniques, such as MRI, as well as appropriate histological samples. The patient underwent androgen deprivation therapy to which RLP responded well and neither systemic chemotherapy or surgery was necessary.

Metastasis to the rectum: A systematic review of the literature

BACKGROUND

Metastatic spread to the rectum is a rare finding, and management of rectal metastases (RM) is not standardized. The aim of the present study was to review the evidence on diagnosis, management and outcomes of RM.

METHODS

A computerized literature search through MEDLINE/PubMed, Embase and the Cochrane databases was performed, applying a combination of terms related to RM. Articles and abstracts were screened and final selection was done after cross-referencing and by use of predefined eligibility criteria.

RESULTS

Final analysis was based on 99 publications totaling 162 patients with RM from 16 different primary tumors. Most common origins of RM were breast (42 patients), stomach (38 patients), and prostate (16 patients). RM occurred metachronously in the majority of patients (77%). The main treatment was surgical resection (n = 32), followed by chemotherapy (n = 16). Median overall survival for breast RM, stomach RM, and prostate RM were 24 months (95% CI 9-39 months), 7 months (95% CI 0-14 months), and 24 months (95% CI 7-41 months), respectively.

CONCLUSION

RM is a rare and highly heterogeneous condition. Surgical treatment appears to be a valuable treatment option in selected patients, while overall prognosis depends mainly on the primary tumor.

Computed tomography and magnetic resonance imaging findings of metastatic rectal linitis plastica from prostate cancer: A case report and review of literature

Linitis plastica is a rare condition showing circumferentially infiltrating intramural anaplastic carcinoma in a hollow viscus, resulting in a tissue thickening of the involved organ as constricted, inelastic, and rigid. While most secondary rectal linitis plastica (RLP) is caused by metastasis from stomach, breast, gallbladder, or bladder cancer, we report an extremely rare and unique case of secondary RLP due to prostate cancer with computed tomography (CT) and magnetic resonance imaging (MRI) findings, including diffusion weighted imaging (DWI). A 78-year-old man presented with approximately a 2-mo history of constipation and without cancer history. On sigmoidoscopy, there was a luminal narrowing and thickening of rectum with mucosa being grossly normal in its appearance. On contrast-enhanced CT, marked contrast enhancement with wall thickening of rectum was noted. On pelvic MRI, rectal wall thickening showed a target sign on both T2-weighted imaging and DWI. A diffuse infiltrative lesion was suspected in the prostate gland based on low signal intensity on T2-weighted imaging and restricted diffusion. A transanal full-thickness excisional biopsy revealed metastasis from a prostate adenocarcinoma invading the submucosa to the muscularis propria consistent with metastatic RLP. We would like to emphasize the CT and MRI findings of metastatic RLP due to prostate cancer.

Metastatic breast cancer to the rectum: A case report with emphasis on MRI features

RATIONALE

Less than 1% of breast carcinomas metastasize to the gastrointestinal tract. The diagnosis is frequently not recognized especially when the history of breast carcinoma is remote.

PATIENT CONCERNS

A 61-year-old female with a remote history of breast carcinoma presented with a 3-month history of change in bowel habits. Colonoscopy showed a circumferential rectal mass with initial impression of primary rectal cancer. MRI of the rectum showed findings that are atypical for primary rectal cancer.

DIAGNOSES

Deep biopsy of the rectal mass confirmed lobular breast carcinoma metastasis to the rectum.

INTERVENTION AND OUTCOMES

The patient was treated with radiotherapy and hormonal therapy. She is symptomatically well 2 years after presentation and remains on hormonal therapy.

LESSONS

Lobular breast cancer which metastasizes to the rectum can mimic primary rectal cancer clinically. The unique MRI features described in our case when present with a concordant history of lobular breast carcinoma should alert the radiologist to the possibility of this diagnosis which has important treatment implications.

Computed tomography features of gastrointestinal linitis plastica: spectrum of findings in early and delayed phase imaging

PURPOSE

To analyze the features of gastrointestinal linitis plastica obtained by computed tomography (CT).

MATERIALS AND METHODS

We conducted a single-center, retrospective analysis of 45 cases of gastrointestinal tract linitis plastica collected over a 10-year period. "Linitis plastica" was defined based on histological characteristics. Primary and secondary linitis plastica were included. Two readers independently assessed the radiological findings (i.e., number of lesions, mass, wall thickening, and enhancement).

RESULTS

The patient cohort comprised 23 men and 22 women with an average age of 63.2 years. The main presenting signs and symptoms were impaired general health and ascites (22/45 patients, 48.8%). The stomach was the affected organ in 68.3% of the cases, while the rectum was affected in 11.7% of the cases. Primary linitis was found in 73.3% of the cases, and solitary lesions were found in 77.8% of the cases. The most common CT finding was wall thickening (91.7%) with a complete disappearance of folds and enhancement of the entire wall at 2 min. Four lesions (6.6%) were described as masses, and only one (1.7%) was described as a wall atrophy.

CONCLUSION

Linitis plastica can affect the entire digestive system. Its potentially secondary nature necessitates a systematic search for a primary tumor. An appropriate CT protocol is required to detect the specific radiological features of this fibrous cancer. CT can help confirm the diagnosis of linitis plastica, rule out differential diagnoses, and indicate the need for deep biopsies where possible.

Rectal cancer in inflammatory bowel diseases: MR imaging findings

PURPOSE

To retrospectively analyze the MR imaging features of rectal cancer in patients with inflammatory bowel diseases (IBD).

MATERIALS AND METHODS

The MR imaging examinations of 13 patients with IBD-related rectal cancer were retrospectively reviewed. MR imaging included T2-weighted, diffusion-weighted (DW), and gadolinium chelate-enhanced MR imaging. MR imaging findings were analyzed and compared with endoscopic and histopathological findings.

RESULTS

Eight patients (8/13; 62%) had active IBD and five (5/13; 38%) had quiescent IBD on MR imaging. Two different tumor patterns were individualized including clearly visible soft-tissue mass (4/13; 31%) (Type 1 tumor) and marked circumferential rectal wall thickening (9/13; 69%) (Type 2 tumor). Twelve tumors (12/13; 92%) showed high signal intensity on T2-weighted MR images. All six tumors studied with DW-MR imaging (6/6; 100%) showed high signal on DW-MR imaging with restricted diffusion on apparent diffusion coefficient (ADC) map. On gadolinium chelate-enhanced MR imaging, heterogeneous enhancement was observed in one tumor (1/13; 8%), whereas 12 tumors (12/13; 92%) showed homogeneous enhancement. MR imaging showed pelvic fistula and intrapelvic abscess in association with four (4/13; 31%) and two tumors (2/13; 15%), respectively.

CONCLUSION

Our limited retrospective study demonstrates that rectal cancer in IBD patients can present as a circumferential wall thickening resembling inflammation and can occur in the absence of fistula or abscess. The use of T2-weighted and DW-MR imaging is recommended to improve rectal cancer detection in patients with long-standing IBD.

MDCT features in the differentiation of T4a gastric cancer from less-advanced gastric cancer: significance of the hyperattenuating serosa sign

OBJECTIVE

The purpose of our study was to evaluate CT findings to differentiate between T4a and less advanced gastric cancers.

METHODS

The institutional review board approved this study and waived informed consent. This study included 228 retrospectively identified patients with surgically confirmed gastric cancer (138 T1, 25 T2, 24 T3 and 41 T4a) and who had also undergone pre-operative CT scan. Transverse and multiplanar reconstruction scans were reviewed in consensus by two other blinded radiologists. The following CT findings that differentiate T4a from less advanced cancers were evaluated: nodular or an irregular outer layer of the gastric wall, haziness of the perigastric fat and a hyperattenuating serosa sign. The CT features of T4a and less advanced gastric cancers were compared by means of univariate and multivariate analyses.

RESULTS

In univariate analysis, nodular or an irregular outer layer of the gastric wall, haziness of the perigastric fat and the hyperattenuating serosa sign were significant in differentiation between T4a and less advanced gastric cancers. In addition, nodular or an irregular outer layer of the gastric wall and the hyperattenuating serosa sign were significant in differentiation between T3 and T4a. In multivariate logistic analysis, the hyperattenuating serosa sign was the most significant finding in differentiation between T3 and T4a (odds ratio, 4.210; 95% confidence intervals, 1.581-11.214; p=0.004).

CONCLUSION

The hyperattenuating serosa sign may be a useful CT finding in differentiation between T4a and less-advanced gastric cancers.

ADVANCES IN KNOWLEDGE

The hyperattenuating serosa sign is associated with gastric cancer with invading the serosa and can facilitate planning of the optimal pre-operative evaluation and treatment.

Case report and review of the literature: Rectal linitis plastica secondary to the lipoid cell variant of transitional cell carcinoma of the urinary bladder

The overall 5-year survival of patients with urothelial carcinoma of the bladder (UC) is about 78%; however, there are some rare subtypes. One of these is the lipoid cell subtype, which bears a very poor prognosis. Another rare disease entity with a poor prognosis is metastasis to the lower gastrointestinal tract in the form of secondary linitis plastica of the rectum. We describe an extremely rare and unique case of rectal linitis plastica secondary to the rare lipoid cell variant of UC.

[Endoscopic and echoendoscopic findings in secondary linitis plastica of the rectum]

Linitis plastica of the rectum consists of intraparietal, subepithelial and circumferential tumoral infiltration of the wall of the rectum leading to a constricted rectum with mural thickening. There is often a delay between symptom onset and diagnosis because this entity mimics a large number of diseases and the findings of endoscopy and conventional biopsies are non-conclusive since the surface mucosa is not usually affected. We present the endoscopic and echoendoscopic findings of two patients with secondary linitis plastica of the rectum.

Metastatic gastric linitis plastica from bladder cancer mimicking a primary gastric carcinoma: a case report

Primary gastric carcinoma is the most common cause of linitis plastica. Less frequently, metastatic gastric cancer from the breast, omental metastases and non-Hodgkin lymphoma involving the stomach have been reported to show similar radiographic findings as for linitis plastica. A metastatic gastric cancer from bladder cancer is extremely rare. We present an unusual case, the first to our knowledge, of gastric linitis plastica that resulted from a metastatic urothelial carcinoma of the bladder.

Scirrhous metastases to the gastrointestinal tract at CT: the malignant target sign

OBJECTIVE

Our objective was to study the presence of a characteristic appearance of metastatic disease to the gastrointestinal tract on contrast-enhanced CT in patients with known malignancies and to investigate its clinical implications.

CONCLUSION

Twenty-five patients with scirrhous metastases had a malignant CT target sign. Careful observation and correlation with clinical history are required to differentiate this unique sign from a benign target sign.

Secondary linitis plastica of the rectum: EUS features and tissue diagnosis (with video)

BACKGROUND

Luminal metastases to the GI tract may be seen at the time of the primary diagnosis or may represent evidence of a distant recurrence.

OBJECTIVES

To determine the prevalence of rectal-wall metastases in patients undergoing an EUS and to describe the EUS features and yield of EUS-guided FNA (EUS-FNA) and Trucut biopsy (TCB).

DESIGN

A case series.

SETTING

A single tertiary-referral center.

PATIENTS

Patients undergoing lower GI (LGI) EUS from July 1, 2005, to October 31, 2007.

INTERVENTION

EUS-FNA and/or TCB.

MAIN OUTCOME MEASUREMENTS

EUS features and cytologic and/or histologic confirmation of secondary rectal linitis plastica.

RESULTS

Over the 28-month period, an LGI-EUS was performed in 598 patients with presumed primary rectal cancer, of whom 6 (1%) were diagnosed with rectal-wall metastases. The EUS features were that of diffuse, circumferential, hypoechoic wall-thickening that mimics that of linitis plastica, breaching the muscularis propria in all cases. EUS-FNA and/or TCB of the rectal wall or perirectal lymph node established a diagnosis in all cases. The primary cancers originated from the bladder (n = 3), breast (n = 1), stomach (n = 1), and a right forearm cutaneous melanoma (n = 1). The time interval from the initial primary cancer diagnosis to that of GI-tract rectal metastasis ranged from 0 days (simultaneous diagnoses) to 119 months (mean +/- SD 49 +/- 43 months).

LIMITATIONS

Although firm EUS criteria of rectal-wall metastases cannot be established based on 6 patients alone, certain features may prove useful for the diagnosis in the clinical practice.

CONCLUSIONS

EUS-FNA and/or TCB can confirm the diagnosis of secondary linitis plastica of the rectum.

[Primary linitis plastica of the rectum]

Linitis plastica of the rectum is an uncommon entity that is difficult to diagnose due to the lack of mucosal lesions on endoscopy, the low diagnostic yield of biopsy and non-specific findings of barium radiology and computerized tomography. Rectal endoscopic ultrasonography has had a radical impact on the differential diagnosis of stenosing lesions of the rectum, among them linitis plastica, allowing diagnosis of this lesion even in patients with negative results of biopsy.

Primary linitis plastica carcinoma of the colon accompanied by peritoneal abscess

We describe the case of a 75-year-old woman with linitis plastica carcinoma of the colon, accompanied by a peritoneal abscess, in which the use of transabdominal sonography enabled prompt detection and diagnosis. Sonographic examinations revealed diffuse wall thickening with blurred layer stratification in the ascending colon. The irregular outer margin of the affected area was surrounded by thickened pericolic fat. A peritoneal abscess covered by the omentum was also found. CT confirmed these findings. We extensively resected the right half of the colon. Histopathologic examination of the excised segment of the colon revealed a poorly differentiated adenocarcinoma with fibrotic infiltration. The patient was discharged 6 weeks postoperatively, and chemotherapy was begun, but she was lost to our follow-up. Although linitis plastica carcinoma of the colon is rare, it must be considered when patients have extensive colonic wall thickening with blurred layer stratification and an irregular outer margin surrounded by thickened pericolic fat. Transabdominal sonography should be considered the imaging modality of choice for the detection and diagnosis of this disease entity.

Halo sign: useful CT sign for differentiating benign from malignant colonic disease

AIM

To evaluate the halo sign for accurately distinguishing benign from malignant colonic wall thickening.

MATERIALS AND METHODS

Computed tomography (CT) examinations of 92 patients (70 men; 22 women; mean age 57 years) with pathologically proven colonic wall thickening (51 benign and 41 malignant) were retrospectively reviewed in a blinded fashion. The affected segment was assessed for presence of the halo sign, degree and uniformity of thickness and density of the intramural stratum.

RESULTS

The halo sign was present in 74.5% (38/51) patients with benign and 7.3% (3/41) patients with malignant bowel disease. The presence of the halo sign was 75.4% sensitive and 92.5% specific for benign bowel wall thickening. All 38 benign halos showed uniform, continuous stratification; only one of three malignant halos met the strict criteria for benign halo.

CONCLUSION

The halo sign is a moderately sensitive and highly specific sign for distinguishing benign from malignant bowel wall thickening. However, it is not pathognomonic for benign disease. Detailed analysis of halo characteristics is necessary to improve the usefulness of this finding.

Postoperative anatomic and pathologic findings at CT following gastrectomy

Helical computed tomography (CT) is useful in identifying postoperative anatomic changes, complications, and tumor recurrence in gastric cancer patients who have undergone gastrectomy. Postoperative anatomic changes can usually be identified on consecutive CT scans. Complications include anastomotic leakage, duodenal stump leakage, intraabdominal bleeding, wound complications, and other less common complications (postoperative pancreatitis, retention of surgical foreign bodies, diffuse peritonitis). The degree and extent of bowel wall thickening is important in diagnosing tumor recurrence; however, CT lacks specificity. Large or conglomerated lymph node metastases can be easily diagnosed at CT; however, small solitary or focal metastases may not be detected or differentiated from nonmetastatic nodes. Ascites, a common finding with peritoneal seeding in gastrointestinal tumors, is well depicted at CT. Hematogenous metastases from gastric carcinoma are most frequently seen in the liver and are best demonstrated with helical CT performed during the portal venous phase of enhancement (sensitivity >90% for the detection of lesions >1 cm). The sophisticated surgical procedures used in gastrectomy can alter normal anatomy and make image interpretation difficult; thus, familiarity with the appearance of postoperative anatomic changes, complications, and tumor recurrence is essential for accurate CT evaluation of affected patients.

CT features of primary colorectal signet-ring cell carcinoma

PURPOSE

The purpose of this work was to evaluate the CT features of 15 patients with primary colorectal signet-ring cell carcinomas.

METHOD

We retrospectively reviewed the CT scans of 15 patients (mean age 44 years) with pathologically proved colorectal signet-ring cell carcinoma. On CT, we evaluated the site and length of the tumor, bowel wall thickening patterns, perirectal or pericolic infiltration, the presence or absence of colonic obstruction, and metastasis to other organs.

RESULTS

The tumors were located in the rectum in nine patients, the sigmoid colon in one, the hepatic flexure in one, the transverse colon in one, the ascending colon in two, and the cecum in one. The tumor length ranged from 4.0 to 10.0 cm (mean 6.1 cm) with mean thickness of 2.1 cm. CT showed concentric bowel wall thickening in all patients ("even" in 8 and "uneven" in 7), target appearance was noted in 4, perirectal or pericolic infiltrations were moderate to severe in 12, and colorectal obstruction was seen in 6. In the tumor spread patterns, lymphadenopathy was noted in 13, invasion to adjacent pelvic organs in 5, peritoneal carcinomatosis in 4, liver metastasis in 2, and periureteric metastasis in 1.

CONCLUSION

Primary signet-ring cell colorectal carcinoma should be included for differential consideration when CT shows a long length of concentric bowel wall thickening and target sign, especially when such findings occur in the rectum and in young patients.

Intestinal metastases from gastric adenocarcinoma: helical CT findings

PURPOSE

The purpose of this work was to describe the helical CT findings of intestinal metastasis from gastric adenocarcinoma.

METHOD

Twenty-three patients with intestinal metastasis from gastric adenocarcinoma found at helical CT were included. CT findings and clinical and pathologic data were reviewed.

RESULTS

The most common characteristic finding was target-like concentric bowel wall thickening (thick inner high-outer low, n = 18) involving multiple long segments with progressive thickening of the enhancing inner layer. Fifteen cases (65%) involved multiple sites, and the ascending colon (n = 12) and rectum (n = 11) were the two most common sites. Peritoneal carcinomatosis (n = 15, 65%) and bowel obstruction (n = 14, 61%) were common associated findings. Regarding the primary lesion, the majority was linitis plastica (n = 16) and poorly differentiated adenocarcinoma with or without signet-ring cell differentiation (n = 14).

CONCLUSION

Intestinal metastasis from gastric adenocarcinoma, especially of the linitis plastica type, most commonly showed target-like long segmental wall thickening with a characteristically thick inner enhancing layer on helical CT.

CT of patients with right-sided colon cancer and distal ileal thickening

OBJECTIVE

The purpose of this study was to analyze the incidence and primary causes of distal ileal wall thickening in 131 patients with right-sided colon cancer.

SUBJECTS AND METHODS

During a 2-year period, 131 patients underwent surgical resection for right-sided colon cancer. Of these patients, we analyzed 13 who had distal ileal wall thickening on CT before surgery and also had the cause determined at pathology. CT findings were analyzed with regard to the morphologic features of colonic tumors, bowel wall involvement patterns of the distal ileum, and changes in the pericolic space.

RESULTS

Distal ileal wall thickening occurred in 13 (10%) of the 131 patients who had right-sided colon cancer. Three patients had polypoid colon cancer, whereas the other 10 had infiltrative colon cancer. The mean thickness of the involved colonic segments was 1.6 cm (range, 1.0-2.2 cm) with a mean length of 5.2 cm (range, 2.5-10.0 cm). Pericolic infiltration was mild in six patients and moderate in four patients. The mean length and thickness of the affected ileal segments were 3.2 cm (range, 1.5-6.0 cm) and 1.1 cm (range, 0.7-2.0 cm), respectively. On histopathologic examination, neoplastic processes involved the distal ileum in nine (69%) of the 13 patients. This involvement was caused by either direct tumor invasion in seven patients or lymphatic spread in two. In four patients (31%), nonneoplastic processes with edema and congestion involved the distal ileum.

CONCLUSION

The distal ileum may be abnormally thickened in about 10% of patients with right-sided colon cancer; this thickening results from tumor extension (69%) or a nontumorous process (31%).