Benign metastasizing leiomyomas are a rare cause of pulmonary nodules. They likely represent a clonal spread of uterine leiomyomas to the lungs. Management includes pathologic diagnosis with long-term surveillance with or without hormonal manipulation.

The primary factors in feeding premature infants are dependent on the development and maturation of digestion and absorption. The maturation of digestive and absorptive functions of carbohydrates, proteins, fats, minerals, and vitamins in the young premature infant were determined in relation to availability of hydrolytic enzymes, such as lipases, proteases, amylases, glucosidases, and lactase. The feeding is dependent on the ability of the premature infant to secrete salivary enzymes, gastric acid, pepsin, pancreatic exocrine enzymes, the presence of enterohepatic circulation, and the hydrolytic and absorptive capacity of the entercocyte. To evaluate the complexity of the gut maturation process, we proposed a unified concept where the ontogeny of the gastrointestinal system is the result of the following four major determinants: genetic endowment, intrinsic developmental and biological clock, endogenous regulatory mechanisms, and environmental influences. The developmental clock represents a predetermined temporal sequence of happenings in ontogeny that is inherently controlled. By 20 weeks of gestation, the anatomic differentiation of the fetal gut has progressed to the extent that it resembles that of a newborn. Secretory and absorptive functions, however, develop at different rates; the intestinal absorptive process is only partially available before 26 weeks of gestation, whereas gastric and pancreatic secretion is only basal and can be stimulated only partially even in the full-term newborn period. Regulatory mechanisms control the expression of the genetic endowment at various stages in gastrointestinal development. Neural-hormonal factors play major roles in the ontogeny of the gut. Adrenalectomy, hypophysectomy, and thyroidectomy delay the development of the gut. Administration of glucocorticoids or thyroxine at the critical stage in maturation causes early appearance of enzymes within the intestine. Other hormones that are potentially important in regulating gastrointestinal development include cholecystokinin, gastrin, secretin, which have trophic effects on the gastrointestinal tract, and insulin, insulin-like growth factors, and epidermial growth factor. The development of gastrointestinal secretory function, particularly in response to hormonal stimulation, has received considerable attention. The degree of response of the target cell is determined not only by the amount of effective hormone reaching it but also by the number and affinity of receptors on its surface. Human newborns have high levels of gastrin in their sera, yet have low acid output. Exogenous gastrin is an ineffective stimulant despite the presence of seemingly "anatomically developed" parietal cells. It seems that neither endogenous nor exogenous gastrin has an effect on the target cell. If one accepts the role of circulating gastrin levels in the regulation of its own receptor, one can hypothesize the absence of a regulatory effect of gastrin in the newborn period. It was shown that hormonal regulation of migrating activity by mot...

Primary high-grade neuroendocrine carcinoma of the esophagus (HNCE) is rare and poorly understood. In this study, we aimed at delineating the clinicopathologic and immunohistochemical characteristics of HNCE diagnosed on the basis of the World Health Organization criteria for pulmonary neuroendocrine carcinomas. We identified 42 (3.8%) consecutive resection cases of HNCE among 1105 esophageal cancers over a 7-year period. Patients' mean age was 62 years (range, 47 to 79 y) with a male to female ratio of 3.7. Dysphagia was present in 79% of patients and tobacco abuse in 50%. Most tumors were centered in the middle (52%) or lower (36%) esophagus; 48% were ulcerated and 31% exophytic. All tumors were sharply demarcated with a pushing border in either solid sheet (83%) or nodular (17%) growth patterns. Pure HNCE was found in 57%, and the remainder also exhibited small components of squamous cell carcinoma (SqCC) or glandular, signet ring cell differentiations. SqCC in situ was present in 50%. Most tumors (88%) were the small cell type with pure oat-like cells in 52%, and the larger spindled, anaplastic, and giant cells were common. Tumor crush artifact (98%) and the Azzopardi effect (88%) were widespread. Extensive lymphovascular (50%) and perineural (33%) invasion and metastasis to regional (48%) and abdominal celiac lymph nodes (29%) were observed. Neoplastic cells were immunoreactive to synaptophysin (100%), CD56 (93%), chromogranin A (67%), p63 (55%), TTF-1 (71%), CK8/18 (90%), CD117 (86%), HER2 (16%), and p16 (84%) antibodies. The 5-year survival rate was 25%, similar to that of SqCC. Lymphovascular and perineural invasion was associated with a worse prognosis.