Linitis plastica of the rectum secondary to metastatic prostate cancer: A case report of a rare presentation and literature review

Secondary rectal linitis plastica caused by prostatic adenocarcinoma - magnetic resonance imaging findings and dissemination pathways: A case report

BACKGROUND

Secondary rectal linitis plastica (RLP) from prostatic adenocarcinoma is a rare and poorly understood form of metastatic spread, characterized by a desmoplastic response and concentric rectal wall infiltration with mucosal preservation. This complicates endoscopic diagnosis and can mimic gastrointestinal malignancies. This case series underscores the critical role of magnetic resonance imaging (MRI) in identifying the distinct imaging features of RLP and highlights the importance of considering this condition in the differential diagnosis of patients with a history of prostate cancer.

CASE SUMMARY

Three patients with secondary RLP due to prostatic adenocarcinoma presented with varied clinical features. The first patient, a 76-year-old man with advanced prostate cancer, had rectal pain and incontinence. MRI showed diffuse prostatic invasion and significant rectal wall thickening with a characteristic "target sign" pattern. The second, a 57-year-old asymptomatic man with elevated prostate-specific antigen levels and a history of prostate cancer exhibited rectoprostatic angle involvement and rectal wall thickening on MRI, with positron emission tomography/computed tomography PSMA confirming the prostatic origin of the metastatic spread. The third patient, an 80-year-old post-radical prostatectomy, presented with refractory constipation. MRI revealed a neoplastic mass infiltrating the rectal wall. In all cases, MRI consistently showed stratified thickening, concentric signal changes, restricted diffusion, and contrast enhancement, which were essential for diagnosing secondary RLP. Biopsies confirmed the prostatic origin of the neoplastic involvement in the rectum.

CONCLUSION

Recognizing MRI findings of secondary RLP is essential for accurate diagnosis and management in prostate cancer patients.

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.