Carcinoma of unknown primary (CUP): an update for histopathologists.

Carcinoma of unknown primary (CUP) is a heterogeneous group of metastatic cancers in which the site of origin is not identifiable. These carcinomas have a poor outcome due to their late presentation with metastatic disease, difficulty in identifying the origin and delay in treatment. The aim of the pathologist is to broadly classify and subtype the cancer and, where possible, to confirm the likely primary site as this information best predicts patient outcome and guides treatment. In this review, we provide histopathologists with diagnostic practice points which contribute to identifying the primary origin in such cases. We present the current clinical evaluation and management from the point of view of the oncologist. We discuss the role of the pathologist in the diagnostic pathway including the control of pre-analytical conditions, assessment of sample adequacy, diagnosis of cancer including diagnostic pitfalls, and evaluation of prognostic and predictive markers. An integrated diagnostic report is ideal in cases of CUP, with results discussed at a forum such as a molecular tumour board and matched with targeted treatment. This highly specialized evolving area ultimately leads to personalized oncology and potentially improved outcomes for patients.

"Showercap" Sign: Spontaneous Uterine Rupture in a Primiparous Woman.

A 32-year-old primiparous woman presented with severe abdominal pain at 21 weeks' gestation. Background history of laparoscopy for chronic pelvic pain and a spontaneous miscarriage was noted. On examination, she was peritonitic and tachycardic with low grade fever and anemia. MRI abdomen demonstrated a uterine rupture with a large cap of clotted blood overlying the uterine fundus with the appearance of a "shower cap" and large volume haemoperitoneum, the presumptive diagnosis was uterine rupture with placental extrusion. Emergency laparotomy confirmed a two litre haemoperitoneum due to a 3cm defect at the uterine fundus through which a portion of placenta and membrane were extruding. Hysterotomy and delivery of the non-viable fetus was performed. The defect was repaired. It is important to remember that there are many causes of acute abdominal pain in pregnant patients, obstetric and other. Uterine rupture is a rare but life-threatening cause. An underlying risk factor is usually identified.