IntroductionMixed glandular-endocrine carcinomas are rare tumours of gastrointestinal tract (MANEC). They are more frequent in stomach and hardly one hundred cases have been described in colon. According to Lewis, they are classified into collision (side by side pattern), composite (intermingled) or amphicrine (neuroendocrine and glandular features inside a same cell). Collision tumours are related to biclonal theory: two simultaneous cancerogenic events. Conversely, multidirectional differentiation from a stem cell is accepted as origin of composite tumours.The aim of this paper is to analyse the behaviour of these tumours, with an especial concern about how these tumours metastasise, and the different theories about carcinogenesis.Presentation of caseWe report a rare case of collision adenocarcinoma-large cell neuroendocrine tumour of colon that after a three-year period of follow-up has presented a retroperitoneal recurrence that features adenocarcinoma and large cell neuroendocrine components.DiscussionAfter an exhaustive review of the English literature, we found that only two cases of collision tumour of colon with metastases showing glandular and endocrine components have been described up to date, so we report the third case, and the first happening in transverse colon.ConclusionWe conclude that not all collision tumours follow the biclonal theory and more studies are needed to clarify the origin of these neoplasms, and consequently, to reach an adequate treatment.

Rectus Sheath Hematoma (RSH) is a rare condition that frequently affect elderly women on anticoagulant therapy. Risk factors include trauma, surgery, cough, iatrogenic, renal or blood disorders. Most patients present a painful mass at the moment of admission, accompanied of a drop of hemoglobin level. Although the vast majority of cases are self-limiting, and managed with conservative treatment (anticoagulation reversal, fluid replacement, blood transfusion, analgesics), there is still a minority of cases that will present hemodinamically inestability and will need selective embolisation or even surgery. US and CT are useful imaging techniques, especially intravenous contrast CT that will select patients for embolisation. Management is a dilemma, and decision of when reintroducing anticoagulation can convert into a challenge. There is a lack of consensus and guidelines about how to manage this entity, and most of literature consist of series of case reports. We report a case of giant rectus sheath hematoma that caused abdominal compartment syndrome and required two embolisation and surgery. This is a peculiar case because although rectus sheath hematoma has been reported, previously, as cause of abdominal compartment syndrome, this is an uncommon presentation and few cases reported in the English literature.