Patients with colon cancer with liver metastases may be cured with surgery, but the presence of additional lung metastases often precludes curative treatment. Little is known about the processes driving lung metastasis. This study aimed to elucidate the mechanisms governing lung vs liver metastasis formation.
Patient-derived organoid (PDO) cultures were established from colon tumors with distinct patterns of metastasis. Mouse models recapitulating metastatic organotropism were created by implanting PDOs into the cecum wall. Optical barcoding was applied to trace the origin and clonal composition of liver and lung metastases. RNA sequencing and immunohistochemistry were used to identify candidate determinants of metastatic organotropism. Genetic, pharmacologic, in vitro, and in vivo modeling strategies identified essential steps in lung metastasis formation. Validation was performed by analyzing patient-derived tissues.
Cecum transplantation of 3 distinct PDOs yielded models with distinct metastatic organotropism: liver only, lung only, and liver and lung. Liver metastases were seeded by single cells derived from select clones. Lung metastases were seeded by polyclonal clusters of tumor cells entering the lymphatic vasculature with very limited clonal selection. Lung-specific metastasis was associated with high expression of desmosome markers, including plakoglobin. Plakoglobin deletion abrogated tumor cell cluster formation, lymphatic invasion, and lung metastasis formation. Pharmacologic inhibition of lymphangiogenesis attenuated lung metastasis formation. Primary human colon, rectum, esophagus, and stomach tumors with lung metastases had a higher N-stage and more plakoglobin-expressing intra-lymphatic tumor cell clusters than those without lung metastases.
Lung and liver metastasis formation are fundamentally distinct processes with different evolutionary bottlenecks, seeding entities, and anatomic routing. Polyclonal lung metastases originate from plakoglobin-dependent tumor cell clusters entering the lymphatic vasculature at the primary tumor site.

Rather than consider endometriosis as an enigmatic disease, reading John Sampson\'s two theories/mechanisms explains virtually all cases affecting the female. It is true that Sampson\'s most recent publication, in 1940, which talks about retrograde menstruation via the fallopian tubes, clearly fails to explain many types of endometriosis, particularly that located in extra-pelvic sites. However, his earlier publications of 1911 and 1912, on radiographic studies of hysterectomy specimens that had been injected with various gelatin/bismuth/pigment mixtures examining the unique uterine vasculature, were more important. These studies enabled him to describe \'the escape of foreign material from the uterine cavity into the uterine veins\' in 1918 and subsequently to demonstrate metastatic or embolic endometriosis in the first of his two important publications in 1927. Later in that same year, in response to \'academic banter\' from other historic gynaecologists, he published a second article that indicated his studies had been redirected to explore the retrograde tubal menstruation idea; this required undertaking his hysterectomies during menses. That work led to his 1940 presentation at the invitation of The American College of Obstetricians and Gynecologists to focus on the second theory/mechanism of endometriosis. This appears to have caused his more important first theory/mechanism to have been forgotten.

Esophageal cancer (EC) is a common digestive system tumor, characterized by high invasion, apparent lethality, and poor prognosis. Direct diffusion is the major metastatic mechanism of early EC, whereas advanced EC is spread mainly by lymphatic metastasis, but also can be transferred to the liver, lungs, bones, and so on, by hematogenous metastasis. The incidence of bone metastasis in esophageal cancer is low, and maxillary metastasis of EC is more rare.
To explore the differential diagnosis in ECMM, the rare metastasis of EC, and the possible mechanisms and predictors of bone metastasis.
The clinical materials of a male patient with maxillary metastasis of esophageal cancer (ECMM) were analyzed. Then, the possible mechanism of the ECMM was discussed.
ECMM may belong to the hematogenous metastasis. The early detection of rare sites of metastasis of EC should be prioritized in tumor marker detection, imaging, pathology, and other diagnostic techniques.

Metastasis is the most fatal characteristics of malignancy tumor, which accounted for more than 90% of tumor-related mortality. Distant organ or tissue metastasis is a sign of poor prognosis in patients with gastric cancer. Tumor cells metastasis is a very complex process including tumor cell transformation, growth, angiogenesis, invasion, dissemination and survival in the circulation, and subsequent adhesion and colonization the secondary organ or tissue. The origin of tumor cell, genetic variation, the circulatory mode and the physiological structure of the metastatic organ determines the specific sites of distant metastasis. In theory, the metastatic lesion is originated from their primary tumor, so they should have the same molecular profile with the primary tumor. But this view has been confirmed to be wrong in various tumors, including gastric cancer. The gene expression of primary gastric cancer and its metastasis have differences, which may contribute to the early diagnosis and individualized treatment of metastasis. However, the heterogeneity of tumor cells is still unclear in different metastasis lesion of gastric cancer, which will be a major focus of future research. In this review, we discuss the basic principles of cancer metastasis, the unique physiological characteristics of the various metastasis organs and the expression of different functions of gene/protein in primary and metastasis of gastric cancer. In addition, we also discuss the diagnosis, prognosis and treatment in various organ metastasis of gastric cancer.