Pedicle stress fracture: an unusual complication of pycnodysostosis

Pycnodysostosis is a rare dysplasia characterised by high bone density and susceptibility to long bone fractures caused by cathepsin K deficiency. Spinal abnormalities have rarely been described in this uncommon inherited bone dysplasia. A 28-year-old female, with a past history of pycnodysostosis and spontaneous leg fractures was hospitalized for a 2-month history of spontaneous low back pain. Physical examination revealed the typical facial and hand features of pycnodysostosis and local lumbar stiffness. No abnormalities were found in laboratory tests, particularly with regard to bone turnover markers. Fracture of the left pedicle of the third lumbar vertebra was suspected on lumbar radiographs and later confirmed by a computed tomography (CT) scan. A dramatic improvement in symptoms was achieved, thanks to a course of injectable calcitonin therapy and rest. To our knowledge, it is the first-ever reported case of pedicle stress fracture in a patient with pycnodysostosis, suggesting that spontaneous fractures resulting from this bone dysplasia do not only affect diaphysis of brittle long bones but could also affect the lumbar spine. Furthermore, the present case confirms previous observations in such patients of frequent spondylolysis, which could lead to abnormal lumbar pedicle stress. The dramatic improvement achieved by calcitonin therapy might be related to osteoclastic dysfunction in pycnodysostosis caused by a deficiency of cathepsin K, a cystein protease involved in bone matrix remodelling.

[Pseudo-myasthenic myopathy in a woman with anorexia nervosa]

Skeletal myopathy, although foreseeable in severe malnutrition, has been rarely reported in patients with anorexia nervosa. We report a case of oculo-oropharyngeal myopathy mimicking myasthenia in a 42-year-old woman with an history of anorexia nervosa, completely reversible after refeeding with carbohydrate diet, mainly chocolate. Nutritional myopathies are not well known and therefore rarely looked for in patients with anorexia nervosa. Classical presentation is a myogenic syndrome with severe type 2 fibre atrophy and biochemical characteristics similar to Mac Ardle's disease. A clinical form mimicking myasthenia gravis has never been reported. Refeeding programme leads to total recovery within a few days.

Molluscum contagiosum profus au cours d’une dermatite atopique traitée par tacrolimus : intérêt du cidofovir

BACKGROUND

Tacrolimus applied locally is a non-steroid anti-inflammatory drug with proven efficacy in atopic dermatitis. Skin infections can occur, especially viral infections.

CASE-REPORT

A 35-year-old male patient had been treated for extensive atopic dermatitis for several months with tacrolimus (Protopic). After six months of treatment, he presented a large eruption of molluscum contagiosum, in particular on the zones that had received a substantial amount of tacrolimus. The treatment was discontinued and application of a preparation containing cidofovir led to the patient's quick complete recovery, without recurrence in the ensuing months.

DISCUSSION

Viral skin infections, in particular poxvirus infections, are prompted by topical immunosuppressant treatments such as tacrolimus, usually in dose-dependent fashion. Paradoxically, they provide protection against bacterial infections by restoring the integrity of the cutaneous barrier. Application of cidofovir successfully treated a severe form of molluscum contagiosum rapidly without any noticeable adverse effects. This confirms several observations about the efficacy and the good safety of this drug in the treatment of infections by DNA viruses. It provides an additional therapeutic prospect for immunodepressed patients who often present extensive and resistant forms of infections that are usually common.

[Hypercalcemia of double origin: association of multiple myeloma and ectopic parathyroidal adenoma]

INTRODUCTION

Multiple myeloma and primary hyperparathyroidism are two causes of hypercalcemia. This association has already been described to be not casual, despite their link is still unknown.

OBSERVATION

We describe a 68 years old woman, without notable background, was admitted for low back pain. Biology showed an IgG Kappa multiple myeloma (stade 3) and an hypercalcemia without renal failure. Hypercalcemia was difficult to control with bisphosphonate and calcitonin. At first, there was also an hypophosphoremia and a high parathormone level (287 pg/ml). Imaging showed spread myeloma impairment and a right paramediastinal tissular mass. Biopsy diagnosed an ectopic parathyroidal adenoma.

DISCUSSION

Multiple myeloma and primary hyperparathyroidism can be associated. They are often revealed by an hypercalcemia difficult to control or refractory to the treatment. Hypophosphoremia can suggest the diagnosis of hyperparathyroidism. Both this observation and litterature (about twenty case reports) suggest that this double diagnosis should be systematicly evoked and explored by an assay of parathormone and a seric proteins electrophoresis in all hypercalcemia.

CONCLUSION

Multiple myeloma and parathyroidal adenoma should be both explored in all hypercalcemia, because they can be associated.

[Medullar cancer of the thyroid associated with dermal mucinosis]

INTRODUCTION

Dermal mucinosis can be associated with numerous pathologies, in particular involving the thyroid, but has never been described in the case of a medullar cancer of the thyroid (MCT).

CASE-REPORT

A 69-year-old man consulted for a facial erythrosis, which had been developing for a few weeks without any identified triggering factor. The skin biopsy showed dermal mucinosis and tests revealed a sporadic medullar cancer of the thyroid with secondary bone, ganglion and medullar localizations.

DISCUSSION

The association between medullar cancer of the thyroid and dermal mucinosis has never been described. Several hypotheses may explain this: the thyroid pathology itself, whatever its nature, the capacity of the MCT to synthesize mucin and the medullar metastatic overgrowth.