Hematogenous Metastases

The vasa recta of the bowel penetrate the wall on the mesenteric border. They then extend intramurally for variable distances before ramifying toward the antimes-enteric border to arborize into the rich submucosal plexus.

The most common hematogenous metastasis to the small bowel clinically encountered is metastatic mela-noma.17 Its dissemination can be observed radiologically to follow, at times, the field of a specific arterial distribution.17 The embolic metastases typically present as

Fig. 14-25. Duplication of terminal ileum.

The intestinal duplication (ID) is identified as a tubular structure without a recognizable mucosal pattern, lying along the mesenteric border of the terminal ileum (TI) with which it communicates.

(Reproduced from Meyers.2)

Fig. 14-25. Duplication of terminal ileum.

The intestinal duplication (ID) is identified as a tubular structure without a recognizable mucosal pattern, lying along the mesenteric border of the terminal ileum (TI) with which it communicates.

(Reproduced from Meyers.2)

Dynamic Ileus

Fig. 14—26. Seeded metastases from ovarian carcinoma.

Multiple masses cause scalloped displacement on the mesenteric borders of ileal loops in the right lower quadrant. Mucosal tethering is also localized to the mesenteric margins.

Note the relationship of these changes to the axis of the small bowel mesentery, indicated by the line of dashes. (Reproduced from Meyers.2)

Fig. 14—27. Seeded metastases from carcinoma of the ovary.

Multiple serosal masses indent the mesenteric margins of angulated ileal loops in the right lower quadrant. Luminal narrowing and some desmoplastic angulation result in proximal obstruction. (Reproduced from Meyers.2)

Fig. 14—27. Seeded metastases from carcinoma of the ovary.

Multiple serosal masses indent the mesenteric margins of angulated ileal loops in the right lower quadrant. Luminal narrowing and some desmoplastic angulation result in proximal obstruction. (Reproduced from Meyers.2)

submucosal filling defects, often with central ulceration ("bull's-eye" lesions), within a single or multiple intestinal loops. However, when visualized on one wall of a bowel loop, they are localized precisely to its antimes-enteric border (Fig. 14-28) in 80% of cases.2 This correlates with experimental studies indicating that strictly mechanical and circulatory factors can account for the distribution of some secondary tumors.19 The radiologic-anatomic observation presumably reflects lodgment and subsequent growth of embolic malignant cells within the smaller arterial arborizations on the an-timesenteric border.

Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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