Large-cell neuroendocrine tumor of the prostate: a case report and review of the literature.

BACKGROUND: Primitive neuroendocrine prostate neoplasms are rarely reported. This entity comprises carcinoïd tumors and poorly differentiated neuroendocrine tumors, mainly those of the small-cell type. Large-cell-type primitive tumors are exceptional, and only nine cases are reported in the literature. Similar to neuroendocrine tumors of the prostate, large-cell-type primitive tumors may be observed in the context of conventional adenocarcinoma during androgen deprivation therapy or as prostatic metastasis of a distant neuroendocrine tumor, mainly pulmonary neoplasms. CASE PRESENTATION: We report a Caucasian case of a mixed prostatic carcinoma, with the largest component being the large-cell neuroendocine carcinoma, in a patient who underwent a total prostatectomy for a localized cancer. Diagnostic, histological, therapeutic and evolutive aspects are reported and discussed. CONCLUSIONS: Large-cell primitive prostate neuroendocrine carcinoma is a rare but aggressive histological entity, which can be associated or not with an adenocarcinomatous component. Mixed forms have a better outcome, mainly when diagnosed at an early stage.

99mTc-MIBI brain SPECT as an indicator of the chemotherapy response of recurrent, primary brain tumors.

BACKGROUND: Malignant brain tumors carry a pejorative prognosis and necessitate aggressive therapy. Chemotherapy can be used in cases of tumor recurrence. With limited response rate and potential toxicity to chemotherapeutic treatment in patients with recurrent glioma, reliable response assessment is essential. AIM: To define the place of 99mTc hexakis 2-methoxyisobutylisonitrile (99mTc-MIBI) Single Positron Emission Computed Tomography (SPECT) in monitoring chemotherapy response in recurrent primary brain tumors. METHODS: In a retrospective analysis, thirty patients were investigated with MIBI SPECT. Imaging was performed 1h after the intravenous injection of 555 MBq of 99mTc-MIBI using a dedicated SPECT system. A MIBI uptake index (UI) was computed as the ratio of counts in the lesion to those in contralateral region. For all patients, we compared changes over time in UI with MRI and clinical data. RESULTS: The changes in UI agreed well with the clinical and MRI-based assessments in 97% of cases. In 44% of these cases, the scintigraphic response appeared before the MRI response. In instances of treatment failure or rebound, the concordance between scintigraphy and MRI was 52%, and the scintigraphic response appeared before the MRI response in 48% of cases. CONCLUSION: This study confirms our previous results obtained on a short series of patients with recurrent glioma, concerning the usefulness of MIBI SPECT in prediction of chemotherapy response. Moreover, in cases of tumor progression, we show that MIBI SPECT is an earlier indicator of escape from chemotherapy, an average 4 months before MRI changes.