Systemic mastocytosis and bone involvement in a cohort of 75 patients.

OBJECTIVES: To investigate bone involvement in a large cohort of systemic mastocytosis (SM) patients, and evaluate the efficacy of bisphosphonate therapy. PATIENTS AND METHODS: From 2000 to 2004, 75 patients with SM according to WHO criteria underwent skeletal x-rays and bone mineral density (BMD) assessment. Sequential BMD assessments were performed in nine patients treated with bisphosphonate (mean follow-up 65 months). RESULTS: 37 patients (49%) had bone involvement according to both x-rays and BMD evaluations: osteoporosis (23 patients, 31%, mean lumbar spine T score: -3 SD), with vertebral fracture (13 patients, 17%), axial skeleton osteosclerosis (six patients, 8%), mixed patterns (three patients), osteopenia with pre-existing fractures (four patients) and focal osteolytic lesion (one patient). Blood count abnormalities were associated with osteosclerosis (p=0.005). In nine patients with osteoporosis and bisphosphonate therapy, mean lumbar spine BMD increased from 0.83 to 0.92 g/cm(2) (+11.1%; ie, +2.05% per year) without recurrence of vertebral fracture. CONCLUSION: Half of adult patients with SM have bone involvement. Osteoporosis is the most prevalent bone manifestation in SM (31%). Bisphosphonate therapy seems efficient to improve lumbar spine BMD during SM-related osteoporosis. Spine x-ray and BMD should be performed in all SM patients to detect those who may benefit from anti-osteoporotic therapy.

[Continued complete remission of Merkel cell carcinoma with in-transit metastasis after treatment with isolated limb perfusion regional chemotherapy]. / Rémission complète persistante d'une tumeur de Merkel avec métastases satellites après traitement par chimiothérapie locorégionale de type membre perfusé isolé.

BACKGROUND: Primitive cutaneous neuroendocrine carcinoma or Merkel cell carcinoma is a rare tumor. It may be large since diagnosis is frequently delayed. The usual treatment is extensive surgical removal and radiotherapy. PATIENTS AND METHODS: A 69-year-old woman presented with a large Merkel cell carcinoma of the right leg. MRI showed a tumor invading the deep layers together with several satellite lesions. There was no regional nodal or visceral metastasis. Regional chemotherapy involving isolated limb perfusion with melphalan was performed in order to avoid amputation. Complete response was achieved a few months later and continues 5 and a half years later with minor sequelae comprising cutaneous sclerosis, pigmentation and mild ankle stiffness. DISCUSSION: Only five cases of Merkel cell carcinoma treated with isolated limb perfusion are reported in the literature: four of these involved local relapse and one was a primary tumor with regional lymph node involvement. Only one patient was still in complete remission 18 months after treatment. Isolated limb perfusion chemotherapy could thus be indicated in the treatment of advanced Merkel cell carcinoma of a limb in the absence of bone or regional lymph node involvement.