Normal variations of the the paranasal sinuses tend to be overlooked but can have pathological consequences, making identification important.

Pseudomyxoma peritonei (PMP) is a rare complication of mucinous tumours of appendiceal or ovarian origin that results in peritoneal and omental implants. Clinical morbidity and mortality arise from the fact that copious amounts of extracellular and peritoneal mucin result in distortion and loss of function of visceral organs. Therapeutic paracentesis is not possible because of the nature of the mucin. Currently, new techniques are being used to attempt to debulk the mucin volume; none, however, has lead to superior outcome.

The Mayer-Rokitansky-Küster-Hauser syndrome is a rare entity characterized by congenital aplasia of the vagina and uterus in the presence of normal ovarian function, in conjunction with a 46 XX karyotype. This condition is mostly signalled by primary amenorrhoea around the time of puberty. We report on its diagnosis in a 4-year-old child presenting with urinary incontinence. Also of interest in our index patient is the presence of a pure urogenital sinus anomaly. This extremely rare association has not been previously diagnosed in childhood.

Leiomyosarcoma (LMS) is an uncommon malignant tumour of smooth muscle origin. It arises in the gastro intestinal tract, retroperitoneum, urinary bladder, uterus and soft tissue. Peritoneal leiomyosarcomatosis (PL) is defined as a peritoneal dissemination of a primary sarcoma. We present a case of leiomyosarcomatosis with wide spread dissemination including involvement of both breasts.

Malignant melanoma (MM) is an unpredictable tumour that can metastasise to any organ, and is well known for its widespread dissemination. The incidence of metastases to the gastro-intestinal (GI) tract is well documented; this, however, is a late manifestation of the disease with an overall poor prognosis. Most GI metastases are asymptomatic and are only discovered on postmortem, with the majority in the small bowel. The presenting symptoms are usually of obstruction or intussusception; GI bleeding is also common. Fistula formation with the small bowel is rare; ours is believed to be the second case documented.