Case report of primary dural lymphoma mimicking a cerebellar meningioma and brief review of literature.

Primary dural lymphoma (PDL) is an extremely rare subtype of primary central nervous system lymphoma arising from the dura mater in absence of systemic disease. The most common histological type is the low-grade marginal zone lymphoma, whereas high-grade lymphomas are unusual. We present a case of primary diffuse large B-cell lymphoma, presenting as PDL in the posterior fossa, originating from the dura mater of the petrous bone covering the surface of the left cerebellum, a location not previously described. A 65-year-old woman presented with sudden onset of severe dizziness was admitted in otolaryngology department then transferred to neurosurgery ward. CT scan revealed a large lesion involving left cerebellum, subsequent MRI of the brain demonstrated an enhancing mass suggestive for petrous bone meningioma. The tumor was excised, and the histopathological examination unexpectedly revealed a diffuse large B-cell lymphoma. The patient received postoperative chemoradiotherapy. 20 months after surgery a good outcome was registered. Due to the rarity of primary dural lymphomas no standard treatment is available, however, gross total or subtotal resection followed by adjuvant therapy seems to be a good choice to manage the pathology.

Calcitriol pulse therapy and histology of parathyroid glands in hemodialysis patients.

BACKGROUND: Calcitriol pulse therapy (CPT) is considered the most appropriate treatment of secondary hyperparathyroidism (sHPTH). This treatment inhibits parathyroid hormone (PTH) synthesis and secretion, suppresses parathyroid cell proliferation and controls parathyroid gland growth. However, not much is known about the effect of such therapy on parathyroid morphology. METHODS: To investigate this, we studied all first parathyroidectomies (PTx, either total or subtotal) effected in 30 hemodialysis (HD) patients referred to our surgery department by five regional dialysis units in 2000-2001. Six patients were excluded from the study because of either the persistence or the precocious relapse (in the 1st 6 months post-operation) of sHPTH. Twenty-four HD patients were considered eligible as four parathyroid glands were ablated in each patient; 96 glands were then examined histologically. The cohort consisted of 16 males and 8 females with a mean age of 54 +/- 13 SD yrs (range 20-73) and a dialysis duration of 142 +/- 71 months (range 14-289). Data concerning calcitriol treatment (doses, administration route and treatment duration) were collected for each patient. The patients were subdivided into two groups according to the treatment effected in the months preceding PTx: group A (n=13), treated by either intravenous (i.v.) (n=12) or per os (n=1) CPT, and group B (n=11), not treated at all with calcitriol or vitamin D sterols. Parathyroid gland morphology and the parenchymal cell distribution of the parathyroid glands were evaluated by a semiquantitative assessment. Serum intact PTH (iPTH), alkaline phosphatase (AP), calcium (Ca) and phosphate (P) levels were studied pre- and post-PTx. RESULTS: Chief cells (CC) were found in all glands, either alone or associated with oxyphil cells (OC). OC were present in 13 of 24 patients (54%); however, it must be underlined that they were present 12 times in group A parathyroid glands (92%), and only once in group B (9%) (p<0.01). Nodular hyperplasia was found in 71% (17/24) of patients: 92% (12/13) in group A, and 45% (5/11) in group B (p<0.05). There were no significant differences in age, gender, dialysis duration, serum levels of iPTH, AP, Ca and P levels between the two groups. CONCLUSIONS: There was a strong association between OC presence in parathyroid glands and CPT. Furthermore, nodular hyperplasia appeared to be associated significantly with CPT. There is still speculation regarding the meaning of these CPT effects on parathyroid gland histology and consequently on sHPTH pathophysiology.