Rare thoracic cancer

Rare thoracic cancers share the same difficulties of other rare cancers for diagnosis and treatment. They have in addition the characteristic of being treated in medical and research units where tobacco related lung carcinoma are largely overrepresented, and gathered recently a large part of the attention of research groups and of the public, because of major therapeutic advances, which are not necessarily shared by the rare thoracic tumours.

Rare thoracic tumours correspond to more than 100 different histological, clinical, radiological, and prognostic entities.
Some rare thoracic tumours are unique to the thorax, whereas others, rarely occurring within the thorax, correspond to tumours more frequent in other organs: for example, sarcomas, NET, lymphomas may develop primarily in the lung. As for all rare tumours, rare thoracic tumours suffer from a limited number of experts and limited therapeutic options.

Rare thoracic tumours share histological complexity and require expert pathological diagnosis. Treatment strategies for rare pulmonary tumours usually rely on surgery, but some such as lymphoma require to apply strategies developed for more frequent disease location. Mesothelioma are diagnosed with extensive disease in a majority of patients, and treatment relies on chemotherapy, possibly with immunotherapy in refractory disease. Thymic malignancies are usually eligible for surgical resection, but may be associated with autoimmune disorders that complexifies the management of patients. Due to the rarity and the complexity of those diseases, each case should be evaluated in an expert multidisciplinary team, consisting of surgeons, thoracic oncologists, radiologist, radiation oncologist, and pathologists.

Desmoplastic small round cell tumour (DSRCT) is a rare and aggressive peritoneal tumour affecting children, adolescents and young adults with an estimated incidence between 0.2 and 0.5 new cases per million per year (48). DSRCT usually presents with a massive tumour burden spread throughout the abdomen and beyond. Recent studies showed that a multimodality approach based on complete CRS in association with HIPEC and postoperative whole abdominal radiation is an effective local control therapy.

Diffuse peritoneal leiomyomatosis (DPL) is a rare disease which is characterised by the dissemination of multiple benign smooth muscle cell-containing nodules throughout the peritoneum, the omentum and the pelvic structures. DPL manifests during adulthood and is predominantly found in women. Malignant transformation is rare and only seen in a few cases. Depending on the extent of the disease, first-line treatment for DPL is surgical excision or CRS.