Background: Malignant melanoma arising from different body compartments may be associated with differing aetiological factors and clinical behaviour, and may manifest diverse molecular genetic profiles. Although many studies have focused on cutaneous melanoma, little is known of mucosal and other types of melanoma. In particular, malignant melanoma of soft parts is different from other melanomas in many respects, yet manifests a common melanocytic differentiation. Mutation of BRAF is now known to be common in cutaneous melanomas, and raises possible new therapeutic options of anti-RAF treatment for these patients. Few data are available for non-cutaneous melanomas. Aims: To study the incidence of BRAF and NRAS mutations in melanomas arising in diverse internal organs. Methods: Fifty one melanomas from various internal organs were investigated for BRAF and NRAS mutation by direct DNA sequencing. Results: BRAF and NRAS mutations were found in two and five mucosal melanomas arising from the aerodigestive and female genital tracts (n = 36). Their occurrence is mutually exclusive, giving a combined mutation incidence rate of 19.4% in mucosal melanomas. Both BRAF and NRAS mutations were absent in malignant melanoma of soft parts (n = 7). BRAF mutation was also absent in uveal melanoma (n = 6), but was seen in two of five cutaneous melanomas. The incidence of BRAF or combined BRAF/NRAS mutations in all non-cutaneous groups was significantly lower than published rates for cutaneous melanomas. Conclusion: Each melanoma subtype may have a unique oncogenetic pathway of tumour development, and only a small fraction of non-cutaneous melanomas may benefit from anti-RAF treatment.

Aims. We report on the unusual case of a 43-year-old man who developed recurrent meningeal hemangiopericytoma and presented with hypoglycemia 6 years after excision of the tumor. Methods and Results. We utilized computed tomography to assure multiple tumor metastasis and cranial recurrence of previous meningeal hemangiopericytoma and clinical laboratory tests and immunohistochemical staining to characterize this case. Magnetic resonance imaging and computed tomography showed the recurrent tumor at original torcular site was increased in size. Abnormal low levels of growth hormone, insulin, and insulin-like growth factor-I except insulin-like growth factor-II were detected in the serum. By immunohistochemistry, the neoplastic cells characteristically express diffusely CD99, bcl2, and variable CD34. After radio- and chemotherapy, serum glucose level of the patient returned to normal. Conclusions. Comparing other brain tumors, meningeal hemangiopericytoma has a higher recurrent and metastatic rate, but this tumor with hypoglycemia is very rare.

N-cadherin is differentially expressed in pulmonary tumours and is predominantly observed in neuroendocrine lung lesions with high expression in typical and atypical pulmonary carcinoids. The level of expression of N-cadherin between types of lung tumours does not appear to indicate malignant potential or aggressive behaviour.