Beyond hematoxylin and eosin: the importance of immunohistochemical techniques for evaluating surgically resected constipated patients

The effect of the area proportion of the metastatic lesion within the central metastatic lymph node on response to therapy in papillary thyroid carcinoma

Lymph node (LN) metastasis has been strongly associated with locoregional recurrence and decreased survival time of patients with papillary thyroid carcinoma (PTC). Although the characteristics of the metastatic LNs (mLN) have been determined, including size, number, micro-metastasis and extra-nodal extension (ENE), further analysis is warranted. The present study introduced a new parameter known as the area proportion of the metastatic lesion within the central mLNs (APmCLN). The objective was to evaluate the impact of the APmCLN on response to therapy in patients with PTC. In total, 355 patients with PTC treated with total thyroidectomy and neck dissection, post-operative radioactive iodine and thyroid-stimulating hormone suppression were retrospectively studied. The patients were classified into two groups: Group A (APmCLN ≤75%) and group B (APmCLN >75%). The association of various clinicopathological characteristics between these two groups was investigated. Univariate and multivariate analyses were used to evaluate risk factors associated with a non-Excellent response to therapy and recurrence-free survival (RFS). The analysis showed that APmCLN >75% was significantly associated with extra-thyroidal extension, clinically apparent nodes (cN1), pathological N1b (pN1b), ENE, greater number and larger size of central mLN and larger size of the central LN metastatic lesion. Furthermore, it was reported that chronic lymphocytic thyroiditis, larger central mLN size and APmCLN >75% were independent risk factors for a non-excellent response to therapy. Finally, it was determined that the rate of excellent response to therapy was significantly higher in pathological N1 (pN1) patients with APmCLN ≤75% (108/144, 75.0%) compared with patients with APmCLN >75% (27/47, 57.4%) (P=0.022). However, there was no significant difference (P=0.247) between patients with APmCLN ≤75% and pN0 (132/164, 80.5%). RFS was 89.4% in patients with pN1-APmCLN >75%, whereas those with pN1-APmCLN ≤75% and pN0 did not experience a relapse. Patients with PTC with APmCLN >75% should be regarded as high-risk and may require more aggressive treatment and careful follow-up.

The enteric nervous system in patients with calculous and acalculous gallbladder

BACKGROUND

It is generally thought that gallbladder motility plays a more or less important role in the pathogenesis of gallstones. Some studies have shown that some abnormalities of its intrinsic innervations, but these studies were usually limited to one cell component.

AIMS

We investigated the main cell components of gallbladder intrinsic innervation in patients with and without gallstones.

METHODS

Archival gallbladder specimens from 39 patients, 27 with gallstones (age range 45-69 yrs) and 12 patients without gallstones (age range 39-71 yrs) were obtained. Full thickness sections were obtained from the gallbladder neck and immunohistochemistry was carried out for enteric neurons (neuron-specific enolase and calretinin), enteric glia (S100) and interstitial cells of Cajal (CD117 and CD34); tryptase staining was also done to distinguish the latter from mast cells.

RESULTS

Apart from calretinin-positive neurons, patients with gallstones featured a significant decrease of neurons, enteric glial cells (EGC) and mast cells compared to those without gallstones; interstitial cells of Cajal were extremely few and only found in two patients, one for each group.

CONCLUSIONS

The intrinsic innervations of the gallbladder is abnormal in gallstone patients, and this may contribute to gallstone formation in these subjects.

The PNEI holistic approach in coloproctology

The psycho-neuroendocrine-immune approach relies on the concept of considering diseases from a holistic point of view: the various components (psyche, nervous system, endocrine system, and immune system) control the diseased organ/apparatus and in turn are influenced by a feedback mechanism. In this article, we will consider the psycho-neuroendocrine-immune approach to coloproctological disorders, by providing clinical cases and discussing them in light of this approach.

Histological Findings in Resected Bowel of Motility-disordered Patients

Gastrointestinal (GI) motility disorders are prevalent conditions associated with pain and bowel dysfunction. Some motility-disordered patients with intractable symptoms have undergone bowel resection aimed at palliating their symptoms. Our objective was to describe a population of motility-disordered patients with histopathological abnormalities identified in full-thickness surgical biopsies. A retrospective cohort study using prospectively collected clinical data and pathology reports was conducted. All adult patients referred to a tertiary motility clinic from 1996 to 2011 who had bowel resection for motility disorder were consecutively sampled. Fisher's exact test was used. Ninety-seven patients were referred for motility disorder during this time and pathology reports were available for 62 patients (63.9%). Hypertrophy or hyperplasia of the myenteric plexus was reported in 13 patients (21.0%). These patients were predominantly females with constipation-dominant symptoms. They were more likely to have objective evidence of colonic inertia ( P = 0.01) than patients without myenteric plexus hypertrophy/hyperplasia. Consistent histopathologic abnormalities of myenteric plexus hypertrophy/hyperplasia were described in 21 per cent of patients with refractory GI motility disorders referred for surgical management. Our findings contrast with the hypoganglionosis reported in the slow transit constipation literature. Future studies are needed to systematically investigate these novel histologic findings through a follow-up immunohistochemical study of stored bowel specimens.

Understanding and treating refractory constipation

Chronic constipation is a frequently encountered disorder in clinical practice. Most constipated patients benefit from standard medical approaches. However, current therapies may fail in a proportion of patients. These patients deserve better evaluation and thorough investigations before their labeling as refractory to treatment. Indeed, several cases of apparent refractoriness are actually due to misconceptions about constipation, poor basal evaluation (inability to recognize secondary causes of constipation, use of constipating drugs) or inadequate therapeutic regimens. After a careful re-evaluation that takes into account the above factors, a certain percentage of patients can be defined as being actually resistant to first-line medical treatments. These subjects should firstly undergo specific diagnostic examination to ascertain the subtype of constipation. The subsequent therapeutic approach should be then tailored according to their underlying dysfunction. Slow transit patients could benefit from a more robust medical treatment, based on stimulant laxatives (or their combination with osmotic laxatives, particularly over the short-term), enterokinetics (such as prucalopride) or secretagogues (such as lubiprostone or linaclotide). Patients complaining of obstructed defecation are less likely to show a response to medical treatment and might benefit from biofeedback, when available. When all medical treatments prove to be unsatisfactory, other approaches may be attempted in selected patients (sacral neuromodulation, local injection of botulinum toxin, anterograde continence enemas), although with largely unpredictable outcomes. A further although irreversible step is surgery (subtotal colectomy with ileorectal anastomosis or stapled transanal rectal resection), which may confer some benefit to a few patients with refractoriness to medical treatments.

Cellular and molecular basis of chronic constipation: Taking the functional/idiopathic label out

In recent years, the improvement of technology and the increase in knowledge have shifted several strongly held paradigms. This is particularly true in gastroenterology, and specifically in the field of the so-called “functional” or “idiopathic” disease, where conditions thought for decades to be based mainly on alterations of visceral perception or aberrant psychosomatic mechanisms have, in fact, be reconducted to an organic basis (or, at the very least, have shown one or more demonstrable abnormalities). This is particularly true, for instance, for irritable bowel syndrome, the prototype entity of “functional” gastrointestinal disorders, where low-grade inflammation of both mucosa and myenteric plexus has been repeatedly demonstrated. Thus, researchers have also investigated other functional/idiopathic gastrointestinal disorders, and found that some organic ground is present, such as abnormal neurotransmission and myenteric plexitis in esophageal achalasia and mucosal immune activation and mild eosinophilia in functional dyspepsia. Here we show evidence, based on our own and other authors’ work, that chronic constipation has several abnormalities reconductable to alterations in the enteric nervous system, abnormalities mainly characterized by a constant decrease of enteric glial cells and interstitial cells of Cajal (and, sometimes, of enteric neurons). Thus, we feel that (at least some forms of) chronic constipation should no more be considered as a functional/idiopathic gastrointestinal disorder, but instead as a true enteric neuropathic abnormality.

Altered expression pattern of molecular factors involved in colonic smooth muscle functions: an immunohistochemical study in patients with diverticular disease

Background

The pathogenesis of diverticular disease (DD) is thought to result from complex interactions among dietary habits, genetic factors and coexistence of other bowel abnormalities. These conditions lead to alterations in colonic pressure and motility, facilitating the formation of diverticula. Although electrophysiological studies on smooth muscle cells (SMCs) have investigated colonic motor dysfunctions, scarce attention has been paid to their molecular abnormalities, and data on SMCs in DD are lacking. Accordingly, the main purpose of this study was to evaluate the expression patterns of molecular factors involved in the contractile functions of SMCs in the tunica muscularis of colonic specimens from patients with DD.

Methods and Findings

By means of immunohistochemistry and image analysis, we examined the expression of Cx26 and Cx43, which are prominent components of gap junctions in human colonic SMCs, as well as pS368-Cx43, PKCps, RhoA and αSMA, all known to regulate the functions of gap junctions and the contractile activity of SMCs.

The immunohistochemical analysis revealed significant abnormalities in DD samples, concerning both the expression and distribution patterns of most of the investigated molecular factors.

Conclusion

This study demonstrates, for the first time, that an altered pattern of factors involved in SMC contractility is present at level of the tunica muscularis of DD patients. Moreover, considering that our analysis was conducted on colonic tissues not directly affected by diverticular lesions or inflammatory reactions, it is conceivable that these molecular alterations may precede and predispose to the formation of diverticula, rather than being mere consequences of the disease.

Colonic diverticular disease: abnormalities of neuromuscular function

Although diverticular disease of the colon (diverticulosis) is a frequent finding in Western countries, its pathophysiologic grounds are still only partially understood. Traditionally considered as an age-related condition, colonic diverticulosis is probably the final result of several factors concurring together to determine the anatomo-functional abnormalities eventually causing outpouching of the viscus' mucosa. Among these factors, a relevant role seems to be played by an abnormal neuromuscular function of the large bowel, as shown by abnormal myoelectrical and motor function repeatedly described in these patients, as well as by altered visceral perception. These anomalies might be related to the recent demonstration of derangement of enteric innervation (especially involving interstitial cells of Cajal and enteric glial cells), mucosal neuropeptides, and mucosal inflammation. The latter may have a role of paramount importance in the development of visceral hypersensitivity, responsible for abdominal pain in a subset of patients.