Differences in PET/CT standardized uptake values involvement and survival compared to histologic subtypes of lung adenocarcinoma.

PURPOSE: Lung adenocarcinoma is histologically diverse but has distinct histologic growth patterns. There is no consensus on the clinical benefit of this histologic model. We aimed to evaluate the differences in the distribution of the preoperative primary tumor positron emission tomography (PET)/computed tomography (CT) standardized uptake values (SUVs) and survival in the lung adenocarcinoma subtypes. METHODS: We retrospectively evaluated the data of 107 patients with resected lung adenocarcinoma who had preoperative PET/CT between 2005 and 2017 in a single center. Patients had lepidic, acinar, papillary, micropapillary, and solid histologic subtypes. We compared fluorodeoxyglucose SUVs and survival data of histologic subtypes. RESULTS: The median age of the patients was 62 years (40-75), 76.4% were male, the median SUVmax was 9.4 (1-36.7), and the median follow-up time was 29 months (3-135 months). The median overall survival (OS) was 71 months and the median progression-free survival (PFS) was 33 months. SUVmax was significantly different in histologic subtypes: values for papillary, micropapillary, solid, acinar, and lepidic subtypes were 9.7, 8, 12, 9.1, and 3.9, respectively (p = 0.000). Solid predominant adenocarcinoma had significantly higher SUVmax than the other subtypes (p = 0.001). Lepidic predominant adenocarcinoma had significantly lower SUVmax than the other subtypes (p = 0.000). There was no significant difference in OS between histologic subtypes (p = 0.66), but PFS was significantly different between the groups (p = 0.017), and the solid subtype had a shorter PFS than the other histologic subtypes. CONCLUSION: Lung adenocarcinoma consists of a diverse group of diseases. Different SUVmax values are seen in different histologic subtypes of nonmetastatic lung adenocarcinoma. Solid predominant types have high SUVmax values while lepidic predominant types have lower SUVmax values. The solid subtype had a shorter PFS than the other histologic subtypes.

A rare case of primary rectal choriocarcinoma and review of the literature.

INTRODUCTION: Primary choriocarcinoma of the colon is an extremely rare neoplasm which has a poor prognosis. Only 18 cases have been previously reported in English medical literature. Here we present a case of primary rectal choriocarcinoma with a good response to chemotherapy and review the literature on this uncommon tumor. CASE REPORT: A 36-year-old woman presented with abdominal pain and vaginal bleeding. Abdominal magnetic resonance imaging revealed 6.9 × 5.3 × 6.4 cm hypervascular mass posterior to uterus very close to rectum. Beta-human chorionic gonadotropin (ß-hCG) level was markedly elevated. Low anterior resection of the rectum with lymph node dissection and total abdominal hysterectomy with bilateral salpingo-oophorectomy were performed. Pathologic diagnosis was reported as colonic choriocarcinoma with a focal component of adenocarcinoma. Post-operative magnetic resonance imaging detected multiple metastatic lesions throughout the liver. The patient was treated with systemic chemotherapy using bleomycin, etoposide and cisplatin (BEP protocol). After three cycles, ß-hCG level decreased to normal and magnetic resonance imaging showed regression of liver metastasis. However, the patient died of respiratory failure due to bleomycin toxicity and pneumonia accompanied by rapid disease progression. DISCUSSION: This is an extremely rare case of primary rectal choriocarcinoma. Due to poor prognosis of the disease, it seems very important to start prompt treatment to improve patient's survival.