Leydig cell tumor of the testis with azoospermia and elevated delta4 androstenedione: case report

BACKGROUND: Secreting interstitial cell (Leydig cell) tumors are rare. In adults, the clinical picture and steroid levels are variable. CASE PRESENTATION: This paper presents a case of left testicular tumor, showing azoospermia with normal serum level of total testosterone, collapsed FSH and LH, and high delta4 androstenedione. Histopathological investigation revealed a Leydig cell tumor. TESE allowed spermatozoa extraction and freezing. Testicular histology found hypospermatogenesis and germ-cell aplasia with interstitial fibrosis. Surgical resection of the tumor resulted in normalization of gonadotropins and fall in serum delta4 androstenedione to subnormal levels in the postoperative period confirming that the tumor was secreting delta4 androstenedione. It was hypothesized that high delta4 androstenedione resulted in intra tumoral 17 β-HSD overtaken by delta4 androstenedione or that 17 β-HSD activity in the tumor was different from that of normal Leydig cells. Three months after surgery sperm analysis found a complete recovery of spermatogenesis. A spontaneous pregnancy occurred 3 months after surgery and a girl was born. CONCLUSIONS: In this case, the diagnosis of testicular Leydig cell tumor secreting delta4 androstenedione was made in a context of azoospermia

The Palaeoproterozoic perturbation of the Global Carbon Cycle : the Lomagundi-Jatuli Isotopic Event

On Earth, carbon cycles through the land, ocean, atmosphere, living and dead biomass and the planet’s interior. The global carbon cycle can be divided into the tectonically driven geological cycle and the biological/physicochemical cycles. The former operates over millions of years, whereas the latter operate over much shorter time scales (days to thousands of years). Within the geological cycle, atmospheric carbon dioxide concentration is controlled by the balance between weathering, biological drawdown, size of sedimentary reservoir, subduction, metamorphism and volcanism over time periods of hundreds of millions of year