Historically, the decapod crustacean circulatory system has been classed as open. However, recent work on the blue crab, Callinectes sapidus, suggests the circulatory system may be more complex than previously described. Corrosion casting techniques were refined and used to map the circulatory system of a variety of crab species (order: Decapoda; family: Cancridae) to determine if the complexity observed in the blue crab was present in other species. Seven arteries arose from the single chambered heart. The anterior aorta, the paired anterolateral arteries, and the paired hepatic arteries exited from the anterior aspect of the heart. The small-diameter posterior aorta exited posteriorly from the heart. Exiting from the ventral surface of the heart, the sternal artery branched to supply the legs and mouthparts of the crab. These arteries were more complex than previously described, with arterioles perfusing all areas of the body. The arterioles split into fine capillary-like vessels. Most of these capillaries were blind ending. However, in several areas (antennal gland, supraesophageal ganglion) complete capillary beds were present. After passing through the capillary-like vessels, blood drained into a series of sinuses. However, rather than being arbitrary spaces as previously described, scanning electron micrographs showed the sinuses to be distinct units. Most of the sinuses formed a series of flattened membrane-bound lacunae. This complexity may qualify the decapod crustacean circulatory system as one that is “partially closed” rather than open.

Maxillary sinus hypoplasia (MSH) is occasionally encountered in otorhinolaryngological practice. The hypoplastic sinus is liable to mucus retention, and cases of MSH usually present as a persistent maxillary sinusitis. Endoscopic surgery has been recommended as an effective treatment for the sinus infection. However, MSH is associated with anomalies of the lateral nasal wall which, if not recognized pre-operatively, can lead to inadvertent surgical damage to the orbit. Although some of these abnormalities can be evident endoscopically, the role of imaging in diagnosis and identification of important surgical landmarks is paramount. A posteriorly placed middle meatal antrostomy is recommended as the surgical treatment of choice.

An odontogenic myxoma of the maxilla with an aggressive clinical course is presented. The tumour arose in a 53-year-old patient, recurred two times after extended maxillectomy and ultimately caused the patient’s death by uncontrollable local disease with infiltration of the cranial cavity.

Microscopically, the tumour showed histological features of a low grade malignant myxosarcoma with cellular areas, enhanced mitotic activity and nuclear pleomorphism. Cytogenetic analysis revealed an unexpectedly aberrant hypertetraploid chromosome complement, that was considered as incompatible with the usual karyotypic patterns of benign tumours.

We present a case of an 81-year-old man with a history of worsening dysphonia of six months duration. A year before a sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease) was diagnosed on a submandibular lymph node biopsy. On presentation the patient showed a mass in the left subglottic area with a modest reduction in the airway space. The patient underwent an endoscopic CO2 laser excision of the mass, without post-operative complications. Histopathological examination and electron microscope images confirmed the previous diagnosis of Rosai-Dorfman disease. The clinical and pathological features of this entity are discussed.

A combination of computed tomography (CT) and magnetic resonance imaging (MRI) is now established as the optimum assessment of sinonasal malignancy. CT and MRI are of particular value in assessing the skull base, orbit and pteryo-palatine and infratemporal fossae. Although MRI offers better differentiation of tumour from surrounding tissue and fluid, coronal CT is still required for the demonstration of bone erosion particularly in the region of the cribriform plate. Thus the extent of local tumour spread may be determined with a degree of accuracy in excess of 98 per cent. However, the final determinant of penetration of the dura and orbital periosteum requires per-operative frozen section assessment. A knowledge of the tissue characteristics and site of origin can be of value in distinguishing some of the commoner sinonasal malignancies such as squamous cell carcinoma, adenocarcinoma, adenoid cystic carcinoma, olfactory neuroblastoma and chondrosarcoma. Imaging, particularly MRI also plays an important role in the post-therapeutic follow-up of patients, indicating areas of residual or recurrent disease, defining suspicious areas for biopsy. Post-operative surveillance is best achieved with three planar T1-weighted MRI, with, and without, gadolinium and axial T2-weighted sequences. The subtraction of the T1 pre- and post gadolinium T1 sequences can be of particular value in delineating recurrence.

Mesenchymal chondrosarcoma (MC) is a rare tumour, with a predilection for the head and neck region. We describe a case of mesenchymal chondrosarcoma arising in the right maxilla extending to the basi-sphenoid. Its computed tomography (CT) and magnetic resonance imaging (MRI) and histopathological features and the management are presented. We also reviewed the literature of reported cases involving the maxilla.

Two cases of Rosai-Dorfman disease with polypoid nasal infiltration mimicking nasal tuberculosis and malignant lymphoma are reported. This rare benign disease was first described by Rosai and Dorfman in 1969 and is characterized by histiocytic proliferation. It is seldom considered in the differential diagnosis of granulomatous diseases due to its rarity and histological similarity to other diseases. Extranodal manifestations of this disease are uncommon. Although no specific treatment can guarantee a sustained remission of this disease, surgery for loco-regional lesions can result in long-term symptomatic control and restoration of function. Both patients underwent endoscopic resection of the nasal polypoid lesions and have subsequently been free of recurrence. Loco-regional infiltration of the nasal cavity by Rosai-Dorfman disease is effectively managed by endoscopic resection.

A 57-year-old man presented with a history of nasal obstruction of five to six years duration. 'Nasal polyps' were removed on several occasions. He had previously had an episode of paraplegia which resolved after the removal of a spinal tumour. Histology from both sites was thought to represent a malignant fibrous histiocytoma. On presentation the patient had computed tomographical (CT) evidence of extensive ethmoidal disease, with threatened intracranial extension. He also had evidence of lung and retroperitoneal disease with pancreas and kidney involvement. The ethmoidal disease was considered potentially lethal and therefore a craniofacial resection was performed. Review of all the histology revealed that the diagnosis was extranodal Rosai–Dorfman disease (sinus histiocytosis). The patient's course is described, and the literature on this disease of unknown aetiology is reviewed.

We present a retrospective study of 106 patients with branchial cleft and pouch anomalies who presented to the Hospital for Sick Children between 1948 and 1990. The relevant embryology of the branchial apparatus is summarized and a theoretical description of individual anomalies given.

Second branchial cleft sinuses were the most common anomalies, and the majority were managed simply, with adequate excision and a low recurrence rate. Five cases of first branchial cleft anomalies are presented, emphasizing the delay in diagnosis, the need for complete excision to prevent recurrence, and for a parotidectomy incision to protect the facial nerve from damage. The two third branchial pouch anomalies presented with a cystic neck swelling, one with recurrent infection and discharge, and the other with stridor. In both, the diagnosis was made at operation. The single fourth branchial pouch cyst was an unexpected finding in a patient with stridor.