Sarcomatous transformation of the royal tumor in a Togolese patient with Recklinghaussen’s disease at Lomé (Togo)

Introduction: malignant tumors including soft tissue sarcomas can occur during neurofibromatosis type 1. We report a case of sarcomatous degeneration of a plexiform neurofibroma with multivisceral metastases in a Togolese patient with neurofibromatosis type 1. Observation: A 33-year-old female patient with neurofribromatosis type 1 presented with an altered general condition, pain and changes in the appearance of the plexiform tumour of her neurofibromatosis, which had been evolving for one month. Physical examination revealed multiple coffee-white spots (greater than 10), with tumours of soft consistency and variable size, scattered over the body. There was also a larger tumour (approx. 9cmx6 cm), located on the inside of the left ankle, fixed, firm and painful to palpation. The abdomen was enlarged and tender, with no tenderness or contracture. Examination of lymph nodes was normal. Anatomopathological examination of the biopsy-exeresis of this tumour revealed a proliferation of clusters of small, rounded, undifferentiated cells with reduced cytoplasm and hyperchromatic nuclei, with clear anisokaryosis and numerous atypical mitotic figures. There were also a few vascular emboli. We therefore concluded that this plexiform neurofibroma was malignant, and the extension work-up revealed pulmonary, pancreatic and adrenal metastases. The patient died 3 weeks after diagnosis in respiratory distress. Conclusion: Malignant degeneration of plexiform neurofibromas is possible in patients with neurofibromatosis type 1. It is therefore important to monitor these patients for early detection in order to limit the risk of metastasis and death.