RESUMEN
Testicular tumors are one of the most commonly observed malignancies among men. An aggressive and rare subtype of the disease, testicular choriocarcinoma, has a worse prognosis due to the tendency of early hematogenous spread to multiple organs and advanced symptoms at presentation time. Characteristic features of choriocarcinoma include elevated beta human chorionic gonadotropin (ß-hCG) in a young male with testicular mass. However, when the primary testicular tumor overutilizes its blood supply and spontaneously regresses, it is presumed to have been "burnt out" with remnants evident by metastatic retroperitoneal lymphadenopathy, scarred tissue, and calcifications. Treatment of advanced testicular cancer may be complicated by a rare entity known as choriocarcinoma syndrome, distinguished by rapid and fatal hemorrhaging of metastatic tumor sites. Prior described cases of choriocarcinoma syndrome involve pulmonary and gastrointestinal hemorrhages. We present an uncommon case of a 34-year-old male with a "burnt out" metastatic mixed testicular cancer who presented with choriocarcinoma syndrome (CS) treated with chemotherapy but developed deadly hemorrhaging of brain metastases. In addition, with the assistance of ChatGPT, we report our experience with this OpenAI tool and its potential uses in medical literature writing.
RESUMEN
Skin sympathetic nerve activity (SSNA) controls skin blood flow and sweat release, and acute noxious stimulation of skin has been shown to cause a decrease in SSNA in the anaesthetised or spinal cat. In awake human subjects, acute muscle pain causes a transient rise in SSNA, but the impact of long-lasting (tonic) stimulation of muscle nociceptors on skin sympathetic outflow, blood flow and sweat release is unknown. We tested the hypothesis that tonic stimulation of muscle nociceptors causes a sustained increase in sympathetic outflow to the skin. SSNA was recorded from the common peroneal nerve of 10 awake human subjects. Tonic muscle pain was induced by infusing hypertonic saline (7 %) into the tibialis anterior muscle over ~40 min, titrated to achieve a constant level of muscle pain. SSNA initially increased following the onset of the infusion, reaching a peak of 164 % of baseline within 5 min, but then showed a prolonged and sustained decrease, reaching a nadir of 77 % in 20 min. Conversely, skin blood flow (and vascular conductance) initially decreased, followed by a progressive increase; there were no consistent changes in sweat release. In 9 of 10 subjects, SSNA and skin blood flow were inversely related. We conclude that sympathetic outflow to the skin exhibits a biphasic response to long-lasting stimulation of muscle nociceptors: an initial increase presumably related to the 'arousal' or 'alerting' component of pain, characterised by increased SSNA and decreased skin blood flow, followed by a prolonged decrease in SSNA and increased skin blood flow. The latter may be a purposeful response that contributes to wound healing.