Gastric fundic gland polyps: a morphological study including mucin histochemistry, stereometry, and MIB-1 immunohistochemistry

Fundic gland polyps are benign lesions, composed of a disorderly arrangement of normal gastric corpus cell types, that occur in a large proportion of patients with familial adenomatous polyposis (FAP) but also develop sporadically in non-FAP patients as well. In this study, the authors evaluated and compared the endoscopic, histological, mucin histochemical, and microscopic stereologic features of 77 fundic gland polyps (FGPs) (15 FAP; 62 non-FAP) to determine if FAP-associated and sporadic lesions are histologically distinct. The authors also analyzed the distribution of mitotically active cells and smooth muscle cells in these lesions using MIB-1 and smooth muscle alpha-actin immunohistochemistry in an effort to determine the pathogenesis of these lesions. The results show that, compared with non-FAP cases, FAP patients with FGPs have a lower male-to-female ratio, a younger mean age at diagnosis, and a higher proportion of cases with multiple polyps. However, no differences were detected between FAP and non-FAP-associated FGPs with respect to any endoscopic, morphological, mucin histochemical, or stereometric features. Eighty-six percent of FGPs showed an increase in smooth muscle content, often in a pericystic distribution. MIB-1-positive proliferative cells were observed not only in the foveolar stem cell region, as expected, but also in the epithelium lining the microcysts and in the gland buds located directly adjacent to the microcysts. The authors conclude that FAP and non-FAP-associated FGPs are histologically identical, and propose that proliferation and subsequent differentiation of aberrantly located proliferative cells in these lesions may explain the histogenesis of FGPs.

Endometriosis of the appendix with decidual polyp formation: a rare cause of acute appendicitis during pregnancy

We report a case of a 28-year-old female, Grava 2, Para I, Ab. 0, who presented acute abdominal pain on the 21st week of her gestation. A diagnosis of acute appendicitis was entertained and an appendectomy performed. The pathologic specimen revealed an inflamed appendix with endometriosis and a marked decidual reaction. A decidual polyp, which occluded most of the appendiceal lumen, is proposed as a rare cause of acute appendicitis during pregnancy.

Pathology of androgen deprivation therapy in prostate carcinoma. A comparative study of 173 patients

BACKGROUND

Leuprolide, an agonist of luteinizing hormone-releasing hormone (LH-RH), and flutamide, an antiandrogen, increasingly are being used in the treatment of clinically localized prostate cancer. Only two small series (of 23 and 12 patients) have been published on the distinctive pathologic changes induced in the prostate by androgen deprivation therapy with discrepancies on the presence of squamous metaplasia, necrosis, and possible tumor destruction by combined androgen deprivation therapy.

METHODS

One hundred and thirteen radical prostatectomy specimens obtained after at least 3 months of leuprolide-flutamide androgen inhibition therapy and 60 nonhormonally treated prostates in randomly selected clinical Stage T2 prostate adenocarcinoma patients were entirely sectioned. Distinctive histologic findings were tabulated and their statistical value determined.

RESULTS

Resection margins of excision were involved by tumor in 43% of untreated and in 19% of androgen-deprived patients. Characteristic changes in androgen-inhibited nontumor glands included atrophy, basal cell prominence, vacuolated luminal cell layer, and squamous and transitional cell metaplasia. Prostatic intraepithelial neoplasia (PIN) was observed in 35% of treated patients. The presence of small tumor glands separated by stroma was the most frequently noted effect of androgen deprivation on prostate adenocarcinoma; pyknosis and branching empty spaces were less frequent. Large clear tumor cells within an inflammatory response was a third histologic pattern. Apparently unaltered tumor areas were observed in 43% of prostates exposed to androgen deprivation therapy.

CONCLUSIONS

Androgen deprivation therapy results in histologically distinctive changes that can be recognized in both nonneoplastic and neoplastic prostate tissue. Residual tumor was present in all 113 treated radical prostatectomy specimens. In addition to glandular shrinkage, therapy was associated with statistically significant reductions in the frequency of high grade PIN and extension of cancer to prostate specimen margins of excisions.

Pulmonary dirofilariasis: first reported case in Puerto Rico

The first case of human pulmonary dirofilariasis in our country is reported. The etiopathogenesis and pathological findings of the zoonosis are discussed.

Adult paratesticular tumors: report of two cases

Paratesticular tumors are uncommon tumors, most being found incidentally at autopsy. The most common benign paratesticular tumor is the adenomatoid tumor. A somewhat less frequent benign paratesticular tumor, papillary cystadenoma, accounts for approximately 33 percent of all the primary epididymal tumors and is frequently seen in patients with Von Hippel-Lindau disease. Malignant tumors are rare. Of these, rhabdomyosarcoma is the most frequent. Seen almost exclusively in the pediatric population, paratesticular rhabdomyosarcomas account for 7 percent of childhood rhabdomyosarcomas. We describe two cases of paratesticular tumors in adults: a papillary cystadenoma of the epididymis in a 72-year old male, and an incidental rhabdomyosarcoma in a 49-year old male.

Fundic gland polyps: prevalence and clinicopathologic features

We evaluated prospectively all gastroscopic examinations performed at two institutions for a period of 24 months with the aim of studying fundic gland polyps in our patient population. Forty-four patients with fundic gland polyps of the stomach were identified among 5554 patients who underwent endoscopy, for a prevalence of 0.8% in our patient population. Twelve additional patients with fundic gland polyps were identified through our surgical pathology referral practice. The patients' ages ranged from 27 to 82 yr, with an average age of 53 +/- 13 yr. The vast majority of the patients were female, with a female-to-male ratio of approximately 5:1. The polyps averaged 2.3 +/- 1.2 mm in size. An average of four polyps per patient were seen, with a range of one to 11.

Colorectal carcinoma: a pathologic and immunopathologic study

Lewis-related blood group antigens are carbohydrate determinants carried on surface glycoproteins and glycolipids of erythrocytes and some epithelial cells. Their expressions in colorectal mucosa has been considered either as a marker of differentiation antigens or of tumor associated antigens. We prospectively studied Lewis-related blood group antigens in patients undergoing colectomy for colonic adenocarcinoma. Immunohematological studies were performed on preoperative blood samples and ABO and Lewis blood groups were determined. Tissue samples were obtained from the adenocarcinoma and from the adjacent non-neoplastic mucosa. The degree of tumor differentiation (grade of the tumor) was analyzed on hematoxylin and eosin stained slides. Immunoperoxidase staining was performed using antibodies against A, B, Le(a), Le(b), Le(x), and Le(y) antigens. The staining results of the colonic carcinoma were compared with those of the non-neoplastic mucosa and with the patient's red blood cell Lewis phenotype. A total of 22 patients were studied, 12 males and 10 females, with an average age of 64 +/- 12 years. There were 12 modified Dukes B and 10 modified Dukes C carcinomas. Le(a), a marker of differentiation antigens, was expressed in the non-neoplastic mucosa of 82% of the specimens. Le(y), a marker of tumor associated antigens, was detected in 77% of the carcinomas while expressed only in 18% of the adjacent non-neoplastic mucosa. Le(x), supposedly a marker for tumor aggressiveness, was found in 55% of the carcinomas. However, it was virtually absent in the five carcinomas which did not invade the pericolic tissues.

Pathology of pulmonary hypertension and schistosomiasis mansoni

We report a case of a 33-year-old woman with grade IV pulmonary hypertension and end stage cor pulmonale secondary to chronic schistosomiasis (bilharziasis). The pathophysiology and morphologic features are discussed. Schistosomiasis is an important etiology to consider in the differential diagnosis of pulmonary hypertension.

Gastric campylobacter-like organisms and active antral gastritis in Puerto Rico

We attempted to verify if the reported association of gastric campylobacter like organisms (GCLO) with active antral gastritis holds true in our population. All patients undergoing elective upper endoscopy were eligible for the study unless they had a history of gastric cancer or previous antrectomy. Biopsy specimens from 100 consecutive patients were examined blindly for the presence of inflammatory activity and/or intestinal metaplasia. The presence of GCLO was determined by the acridine orange fluorescence technique. A total of 131 antral biopsies examined were classified as either normal, active gastritis, chronic gastritis with activity and chronic gastritis without activity. GCLO were identified in 84% of the biopsies with inflammatory activity (active gastritis and chronic gastritis with activity). However, GCLO were found only in 11% of those biopsies with chronic gastritis without activity. It is therefore our conclusion that the previously reported association of GCLO with active gastritis holds true for our population.

Serum cholesterol levels in Puerto Rican volunteer blood donors

The blood samples of four hundred and fifty eight healthy volunteer blood donors were analyzed to determine their serum lipid profile. Based on these lipoprotein analyses, it was concluded that approximately 12% of the sampled population was in a high risk group for coronary heart disease.

Biliary tract disease due to Fasciola hepatica: report of a case

We report a case of a 23 year old woman who presented with symptoms of biliary tract disease to our University Hospital in Bayamón, Puerto Rico. A diagnosis of chronic cholelithiasis was made and the patient was taken to surgery. An adult Fasciola hepatica was recovered from the common bile duct. We review the pathobiology of this uncommon zoonosis.

Cholecystitis due to Schistosoma mansoni, fact or fancy

A case of a 50-year-old female with schistosomiasis of the gallbladder is reported. The clinical and pathological findings are presented.

Structural features of the apical and tubulovesicular membranes of rodent small intestinal tuft cells

Tuft cells are present in most columnar epithelia derived from endoderm including the small intestine. They are characterized by long, wide apical microvilli and an extensively developed cytoplasmic tubulovesicular system. We examined in detail the structural features of the apical plasma membrane of small intestinal tuft cells from adult guinea pigs, rats, and adult and suckling mice with freeze-fracture and conventional transmission electron microscopy methods and utilized cationized ferritin and horseradish peroxidase as tracers to determine whether tuft cells endocytose macromolecules. The microvillus membrane of intestinal tuft cells has few P-face intramembrane particles, displays little alkaline phosphatase activity, and is highly enriched in cholesterol. Tuft cell tight junctions resemble those of absorptive cells in strand count and strand-to-strand crosslinks but, unlike those of absorptive cells, they display many abluminal free-ending strands. Tuft cells of adult and suckling mouse intestine show no evidence of internalization of cationized ferritin or, in suckling mice, uptake of horseradish peroxidase. We conclude that the microvillus membrane of small intestinal tuft cells is protein-poor but cholesterol-rich and that small intestinal tuft cells do not endocytose macromolecules in bulk from the intestinal lumen.

Analysis of absorptive cell occluding junction structure-function relationships in a state of enhanced junctional permeability

Junctional strand count, the number of individual junctional strands which intersect a perpendicular, has been widely used as a morphological estimate of the ability of an occluding junction to resist passive transjunctional molecular flow. Such junctional analysis, which requires the study of freeze fracture replicas, has been useful in studies of occluding junction structure function relationships in unperturbed epithelia and in intestinal epithelia under conditions which lead to increases in junctional resistance. It is unclear if the above junctional structure-function correlates also exist in intestinal or in other epithelia under conditions which result in a state of enhanced junctional permeability. To gain further insight into occluding junction structure-function relationships under such conditions, we utilized an in vivo hypertonic perfusion model previously shown to result in the transfer of luminal macromolecules into the paracellular space of small intestinal villus epithelium. After a 1-hour perfusion with either 600 mOsmoles or 750 mOsmoles mannitol solutions, the macromolecule horseradish peroxidase diffusely filled the paracellular spaces of the upper half of villi. However, analysis of thin sections showed that only junctions at the tip of villi were leaking this tracer. Freeze fracture analysis revealed occluding junction structural abnormalities most marked at the villus tip thus corresponding to the site of transjunctional horseradish peroxidase leak. The most frequent abnormality noted was loss of strand-strand crosslinking and dilation of the interstrand compartments. At such sites, wide unobstructed channels could be traced through much of the junction. However, the apical junctional strand was never noted to display unequivocal discontinuities. Subsequent in vitro studies of perfused tissues revealed that dose dependent decreases in transepithelial resistance and junctional charge selectivity were induced by hypertonic mannitol perfusions. These studies indicate that: paracellular localization of a luminally applied tracer may result from a transjunctional leak at a distant site with subsequent lateral diffusion of the marker; traditional junctional strand count-function relationships may not hold in states which lead to the rearrangement of junctional architecture; and, at least the apical junctional strand may become permeable to macromolecules without the introduction of morphologically detectable strand discontinuities as assessed by routine freeze fracture techniques.(ABSTRACT TRUNCATED AT 400 WORDS)

Intrahepatic biliary cystadenoma. Clinical, radiological, and pathological findings

A 24-year-old white woman presented with abdominal discomfort associated with a firm, nonpulsatile hepatic mass. Radiological examination, which included radionuclide liver scan, abdominal ultrasonography, computed tomography, and hepatic angiography, demonstrated a large, globular, multilocular cyst arising from the left lobe of the liver. A left hepatic lobectomy was performed, and gross examination of the specimen confirmed the cystic nature of the lesion. Histologically, the multiple locules were lined by a single layer of tall cuboidal to columnar cells, which were comparable to those of native biliary tract epithelium. There was little evidence of cellular pleomorphism, and invasion into the underlying mesenchymal stroma was not present. A diagnosis of intrahepatic biliary cystadenoma was made. The clinical, radiological, and pathological findings of this neoplasm are presented and its differential diagnosis discussed.

Cryptosporidium: cellular localization, structural analysis of absorptive cell-parasite membrane-membrane interactions in guinea pigs, and suggestion of protozoan transport by M cells

In ilea of spontaneously infested guinea pigs, we examined the interface between the plasma membranes of cryptosporidia and absorptive cells using thin section and freeze fracture techniques. Initially, cryptosporidia invaginate microvilli, and the resulting redundant folds of membrane envelop the protozoan, thereby internalizing it in a membrane sac of host cell origin. Subsequently, a pentalaminar membrane fusion site develops at the base of the protozoan between the parasite's outer plasma membrane and the internalized host membrane. The membrane domains isolated by this fusion site are then modified: the host membrane disintegrates, and the isolated parasite membrane, which now directly contacts absorptive cell cytoplasm, becomes amplified. While cryptosporidia are restricted to the apex of absorptive cells, they may be found deep within the cytoplasm of M cells overlying Peyer's patches. Moreover, both intact and partially digested cryptosporidial organisms associate with macrophages subjacent to such M cells. These findings define the intracellular localization of cryptosporidia and suggest that cryptosporidial antigens may be sampled by intestinal lymphoid cells at sites underlying M cells.

Partitioning of paracellular conductance along the ileal crypt-villus axis: a hypothesis based on structural analysis with detailed consideration of tight junction structure-function relationships

Current models of intestinal transport suggest cells which absorb ions are located on the villus while secretory cells are located in the crypt and putatively have paracellular pathways which are highly conductive to Na+. One approach to assess possible variation in small intestinal paracellular conductance along the crypt-villus axis is to morphometrically analyze the structural aspects of crypt and villus tight junctions (TJs) which relate to paracellular resistance. Such detailed analysis of junctional structure in this heterogeneous epithelium would permit one to compare intestinal TJ structure-function relationships with those in a structurally simpler epithelium such as that of toad urinary bladder. This comparison would also be of considerable interest since previous similar comparisons have failed to consider in detail the geometric dissimilarity between these two epithelia. We applied light, electron microscopic, and freeze-fracture morphometric techniques to guinea pig ileal mucosa to quantitatively assess, for both crypts and villi, linear TJ density, relative surface contributions, and TJ strand counts. Mean linear TJ densities were 76.8 m/cm2 for crypt cells and 21.8 m/cm2 for villus absorptive cells. Mean TJ strand counts were 4.45 for undifferentiated crypt cell TJs and 6.03 for villus absorptive cell TJs. The villus constituted 87% and the crypt 13% of total surface. We utilized these data to predict paracellular conductance of crypts vs. villi based on equations derived from those of Claude (P. Claude, J. Membrane Biol. 39:219-232, 1978). Such analysis predicts that 73% of ileal paracellular conductance is attributable to the crypt. Furthermore, we obtained literature values for paracellular resistance in mammalian ileum and toad urinary bladder and for toad bladder TJ structure and linear density and constructed a relationship which would allow us to more accurately compare TJ structure-function correlates between these two epithelia. Such a comparison, which considers both surface amplification and TJ structure and distribution in these epithelia, shows that one would predict in vitro measured values for paracellular resistance should be approximately two orders of magnitude less in mammalian ileum than in toad urinary bladder. This predicted discrepancy (115-fold) correlates well with the observed difference (100-fold).(ABSTRACT TRUNCATED AT 400 WORDS)

Ampullary somatostatinoma: psammomatous variant of gastrointestinal carcinoid tumor--an immunohistochemical and ultrastructural study. Report of a case and review of the literature

A 28-year-old man presented with epigastric pain and obstructive jaundice associated with a histologically and immunologically unusual variant of carcinoid tumor involving the ampulla of Vater. The tumor contained abundant psammoma bodies and exhibited immunoreactivity only for somatostatin. Immunoperoxidase studies for insulin, glucagon, vasoactive intestinal peptide, calcitonin, serotonin, and ACTH had negative results. In contrast to most somatostatinomas of pancreatic origin, clinically this ampullary somatostatinoma was not accompanied by features of the somatostatinoma syndrome. A literature review of the clinical and hormonal features in reported cases of gastrointestinal and pancreatic somatostatinomas is presented.