[Merkel cell carcinoma of the skin: two case reports located at the hand, with a review of litterature]. / Le carcinome cutané de Merkel: revue de la littérature à propos de deux localisations à la main.

The Merkel cell carcinoma of the skin are rare neuroendocrine tumours, with a dermal location. Their severity and metastatic potential are higher than cutaneous melanomas'. Two cases are reported at the hand. A review of literature displays the pejorative prognosis of these tumours. Hand surgeons must be aware of them, in order to fasten the diagnosis and include the patient among a multidisciplinary medical team.

Langerhans' cell histiocytosis of the labyrinth in adults.

OBJECTIVE: To describe and analyze three unusual cases of Langerhans' cell histiocytosis of the temporal bone in adults. STUDY DESIGN: Retrospective case review. SETTING: A tertiary referral center. PATIENTS: Three adult patients with progressive sensorineural or mixed hearing loss, vertigo, and tinnitus as presenting symptoms of Langerhans' cell histiocytosis of the temporal bone. INTERVENTION: Patients were evaluated by means of computed tomography and magnetic resonance imaging. All patients underwent complete surgical excision of the lesion via a transmastoid approach, extended to a translabyrinthine approach in one case. One patient with a multifocal disease underwent excision of a mandibular lesion 1 year later, followed-up by chemotherapy. RESULTS: The Langerhans' cell histiocytosis was located adjacent to or within the area of the endolymphatic sac region in all cases. The middle ear was spared. Hearing function was preserved in the two patients who had serviceable hearing preoperatively. No complication occurred. CONCLUSION: Langerhans' cell histiocytosis of the temporal bone is centered on or adjacent to the endolymphatic sac. The fact that the endolymphatic sac plays an immunologic role in the inner ear suggests that the infiltration of the Langerhans' cell may derive from it.