F ibroadenomas are common benign lesions of the breast that usually present as a single breast mass in young women. They are assumed to be aberrations of normal breast development or the product of hyperplastic processes, rather than true neoplasms. The clinician often faces the dilemma whether to remove the mass or to monitor it by means of periodic follow-up examinations. Although removal of these lesions is a definitive solution, surgery may involve unnecessary excisions of benign lesions and unbecoming cosmesis. Moreover, a policy of conducting surgery on all patients with fibroadenomas would place an enormous burden on health care systems. A balanced and rational approach to the management of a fibroadenoma of the breast needs to address the crucial questions about its association with breast cancer, especially whether or not it is a marker of increased risk of breast malignancy. Another consideration to be weighed is that a substantial percentage of these lesions undergo spontaneous regression. Herein, based on our review of the current data on fibroadenomas of the breast and our experience, we propose practical algorithms for their management. INCIDENCE AND RISK FACTORSThere are no clear-cut data on the incidence of fibroadenomas in the general population. In one study, the rate of occurrence of fibroadenomas in women who were examined in breast clinics was 7% to 13%, 1 while it was 9% in another study of autopsies. 2 Fibroadenomas comprise about 50% of all breast biopsies, and this rate rises to 75% for biopsies in women under the age of 20 years. 3,4 Fibroadenomas are more frequent among women in higher socioeconomic classes 5-7 and in dark-skinned populations. 8 The age of menarche, the age of menopause, and hormonal therapy, including oral contraceptives, were shown not to alter the risk of these lesions. 6,7,9,10 Conversely, body mass index and the number of full-term pregnancies were found to have a negative correlation with the risk of fibroadenomas. [5][6][7]9,11 Moreover, consumption of large quantities of vitamin C and cigarette smoking were found to be associated with reduced risk of a fibroadenoma. 7,12,13 No genetics factors are known to alter the risk of fibroadenoma. However, a family history of breast cancer in firstdegree relatives was reported by some investigators to be related with increased risk of developing these tumors. 14,15 PATHOLOGYFibroadenomas usually form during menarche (15-25 years of age), a time at which lobular structures are added to the ductal system of the breast (Fig. 1). Hyperplastic lobules are common at that time, and may be regarded as a normal phase of breast development. 16 Hyperplastic lobules were shown to be histologically identical with fibroadenomas. 10,17 Analyses of the cellular components of fibroadenomas by means of polymerase chain reaction demonstrated that both the stromal and the epithelial cells are polyclonal, 18 supporting the theory that fibroadenomas are hyperplastic lesions associated with aberration of the normal maturation of the breast, ra...

A review of 561 cases of cecal volvulus that were published between 1959 and 1989 along with 7 new cases, was performed to characterize the clinical and laboratory profile and to evaluate the various surgical options in treating this life-threatening condition. The age and sex distribution of these patients have changed over the years and shifted toward older patients (mean, 53 years) and female predominance (female:male ratio, 1.4:1). The clinical presentation was usually of distal closed-loop small bowel obstruction. Forty-six percent of the plain abdominal radiographs were suspected for cecal volvulus, but only 17 percent were diagnostic. Barium enema had a high rate of accuracy (88 percent) and was associated with minimal complications. True volvulus was 6 times more common than bascule, and gangrenous cecum was found in 20 percent of cases. Detorsion alone and cecopexy had almost similar complications, mortality, and recurrence rates (15, 10, and 13 percent, respectively), whereas, resection, which was performed primarily for gangrenous cecum, had higher rates. However, the highest rates of complications (52 percent), mortality (22 percent), and recurrence (14 percent) were noticed after cecostomy. These data suggest that resection should be reserved for patients with necrotic cecum and that detorsion is sufficient for patients with viable cecum. Cecostomy should be abandoned.

A method is outlined that completely separates intracellular and extracellular information in NMR spectra of perfused cells. The technique uses diffusion weighting to exploit differences in motional properties between intra-and extracellular constituents. This allows monitoring of intracellular metabolism, and oftransport of small drugs and nutrients through the cell membrane, under controlled physiological conditions. As a first example, proton spectra of drug-resistant MCF-7 human breast cancer cells are studied, and uptake of phenylalanine is monitored.To rationally design and test chemotherapeutic drugs, it is important to gain an understanding of basic tumor cell metabolism and transport. Monitoring of prolonged metabolic processes under controlled conditions requires continuous perfusion of a batch of a certain cell type, a procedure currently applied to 31P magnetic resonance (MR) studies of cells embedded in an agarose gel (1, 2). This setup (Fig. 1) provides an ex vivo tumor model with actively metabolizing cells.A major problem encountered in the NMR study of cells and organs is discrimination between intra-and extracellular contributions to the spectrum. This problem is more pronounced when the extracellular fraction increases and therefore depends on cell density. In ex vivo studies, this density may be orders of magnitude lower than in vivo. For instance, for breast cancer cells embedded in agarose gel, the extracellular water volume is about a factor of 100 larger than the total intracellular one. Thus, the NMR signal from a 0.1 mM metabolite in the perfusion medium will be comparable in intensity to 10 mM of this same metabolite in the cell, complicating the interpretation of signal intensity changes in terms of intracellular metabolite concentrations. For proton studies an additional problem arises due to the presence of the intense water resonance. For the typical example above, total intra-and extracellular water has a signal intensity that is a factor of about 106 higher than that for a 10 mM metabolite. As a result, proton spectra of intracellular metabolites in perfused cell cultures have never been reported. However, proton experiments can provide information about many compounds in the free metabolite pool of the cell as well as about most drugs, and it is important to find a solution for these difficulties. Proton spectra of cell suspensions have been reported (3, 4), but separation of intra-and extracellular signals is not straightforward.Here we address the problem using the difference in motional properties ofthese components (5-10). Intracellular species diffuse in the cellular matrix with an effective diffusion constant Di, which depends on several factors-e.g., molecular size, bonding, viscosity, temperature, and possible restrictions due to compartmentation (5-9, 11, 12). When extracellular, these species have a diffusion constant De in neat medium but also flow through the perfusion vial holding cells and their support system (an agarose gel). In this paper we use these di...

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