The highveld mole-rat, Cryptomys hottentotus pretoriae, is a cooperatively breeding rodent that exhibits seasonal breeding and a reproductive division of labour. Body mass, reproductive-tract morphometrics, ovarian histology, and plasma oestrogen and progesterone concentrations were studied for both reproductive and non-reproductive females from 55 colonies, the main objective being to determine the inclination of this species towards seasonal breeding. Offspring are born from July through to November. However, qualitative analysis of ovarian histology revealed that reproductive females retain the potential for ovulation and subsequent production of corpora lutea during the late-summer nonbreeding period (December-March). Seasonal differences were found in ovarian morphometrics and hormone concentrations that are associated with enhanced follicular activation in April and May and subsequent conceptions from July through to November during the breeding period. The nonbreeding period coincides with maximal dispersal opportunities in the summer-rainfall areas inhabited by the highveld mole-rat. Body mass, reproductive-tract morphometrics, testicular histology, and plasma testosterone concentrations were determined for reproductive and non-reproductive males from 37 colonies. Available evidence suggests that there is a gradual increase in testicular mass for reproductive males as the breeding season approaches, but after September the testicular parameters fall. Seminiferous-tubule diameter was significantly greater in reproductive males but exhibited no seasonal variation. Testosterone concentrations were higher in reproductive males. Current data support a lack of gonadal regression in males during the nonbreeding season.Résumé : Le rat-taupe Cryptomys hottentotus pretoriae est un rongeur qui se reproduit de façon coopérative, dont la reproduction est saisonnière et qui pratique la répartition des tâches reliées à la reproduction. Nous avons déterminé la masse du corps, la morphométrie du système reproducteur, l'histologie des ovaires et les concentrations plasmatiques d'oestrogène et de progestérone chez des femelles reproductrices et non reproductrices de 55 colonies, dans le but de vérifier la tendance à une reproduction saisonnière chez cette espèce. Les petits naissent entre le début de juillet et la fin de novembre. Cependant, une analyse qualitative de l'histologie des ovaires démontre que les femelles reproductrices gardent leur potentiel d'ovulation et restent capables de produire ensuite des corps jaunes pendant la saison non reproductive en fin d'été (décembre à mars). Il existe des différences saisonnières dans les mesures morphométriques de l'ovaire et les concentrations hormonales, différences associées à la plus grande activité folliculaire en avril et en mai et aux conceptions subséquentes de juillet à la fin de novembre au cours de la période reproductive. La période non reproductive coïncide avec les probabilités maximales de dispersion dans les régions à pluies estivales habitées par le rat-taupe...

All 3 radiographic techniques, conventional radiography, CT, and magnetic resonance imaging (MRI), have inherent advantages and disadvantages; however, all 3 should be routinely used in the diagnosis of OM. The results of CT and MRI can accurately reveal margins of tumors and greatly aid in diagnosis.

The central calcifying odontogenic cyst (CCOC) is a rare lesion. This paper reports a new case, reviews the clinical, histomorphological and radiographic features reported in the literature and describes the CT and MRI features of this new case. We postulate that, as part of an evolutionary process, cystic COCs originate as unilocular lesions but may later become multilocular. The role of advanced imaging and histology in the diagnostic process are discussed.

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A desmoplastic variant of ameloblastoma with osteoplasia in the stroma is reported. This tumour presented in the canine/premolar region of the left maxilla of a 31-year-old woman. It was treated by partial hemimaxillectomy and immediate reconstruction with a non-vascularised iliac graft. The location of this lesion, its histology and radiological features differ from those of the conventional ameloblastoma. The behaviour and prognosis of the desmoplastic ameloblastoma (DA) cannot at this stage be predicted due to the small number of cases that have been reported and a lack of long-term follow-up. To our knowledge this is the first documentation of the CT and MRI features of desmoplastic ameloblastoma with pathologic correlation.