Miscellaneous conditions of the appendix

Acellular mucin in non-neoplastic inflammatory conditions of lower gastrointestinal tract

PURPOSE

In the context of neoplasia, acellular mucin in lower gastrointestinal (GI) tract implies occult mucin-producing tumor and warrants additional workup. The clinical significance of acellular mucin in benign conditions remains unclear.

METHODS

Lower GI tract surgical specimens with acellular mucin without documented neoplastic conditions (colonic diverticulitis (n = 16), appendicitis (n = 14), and others (n = 8)) were retrieved. Low grade appendiceal mucinous neoplasm (LAMN) (n = 24) and diverticulitis without acellular mucin (n = 28) were used as controls for appendicitis and diverticulitis cases, respectively. Clinical data, histological findings, and additional workups performed due to acellular mucin were collected.

RESULTS

Patients with appendicitis with acellular mucin frequently presented with signs and symptoms of acute appendicitis (p = 0.016) compared to LAMN. 71 % were interval appendectomy, and 57 % had diverticula. In colonic diverticulitis cohort, no differences were found in terms of the duration of symptoms, age, gender and the degree of inflammation between the groups with and without acellular mucin. Seven of 8 patients with other conditions with acellular mucin had a history of abdominal surgery or fistula. Additional workup included levels (n = 7), consults (n = 11), and stains (n = 4).

CONCLUSION

Acellular mucin can be seen in a variety of benign conditions but this phenomenon is probably under-recognized and leads to additional investigations. Acellular mucin is likely translocated from the lumen through diverticulum or mural defect. Considering clinical context is crucial in providing accurate diagnosis while preserving laboratory resources.

Micronodular PEComas of the appendix

AIMS

Perivascular epithelioid cell tumours (PEComas) of the appendix have been reported very rarely. In this study, we describe three cases of a distinctive micronodular proliferation in the appendix consistent with a variant of PEComa. Although known as 'granular degeneration of smooth muscle' in prior reports, we reappraise its clinicopathological, immunohistochemical and ultrastructural features which support a change in classification.

METHODS AND RESULTS

Patients were two females (aged 33 and 41 years) and one male (aged 41). None had a history of tuberous sclerosis. Histologically, each case demonstrated a multifocal nodular proliferation towards the distal tip of the appendix, composed of epithelioid cells with abundant granular eosinophilic to clear cytoplasm. By immunohistochemistry, the lesional cells were positive for muscle markers [smooth muscle actin (SMA) and desmin], melanocytic markers (HMB45, melan A), cathepsin K and the lysosomal marker NKI-C3 in each case. MITF was positive in two of three cases. None expressed S100 protein. Electron microscopy in one case revealed striated electron-dense structures consistent with pre-melanosomes. Follow-up, available in one case, showed no recurrence at 5 years.

CONCLUSIONS

We propose the term 'micronodular PEComa' for this appendiceal lesion to reflect more accurately its histological and immunohistochemical characteristics, which include consistent positivity for both muscle and melanocytic markers. Micronodular PEComa seems to follow an indolent course, consistent with its uniformly low-grade histological features, and appears to be unassociated with tuberous sclerosis.

Peripheral Cytotoxic T Cell Lymphoma of the Appendix Presenting as Acute Appendicitis

Introduction

Lymphoma of the appendix is a rare cause of acute appendicitis; however, acute appendicitis is a common first manifestation of appendiceal lymphomas. Cytotoxic peripheral T cell lymphoma (PTCL) is a type of aggressive non-Hodgkin lymphoma that portends a generally poor outcome. Cytotoxic PTCL of the appendix is extremely rare with few cases reported in the literature. Case Presentation. This is the report of a 23-year-old man who had experienced lower abdominal pain for three months before presenting to the emergency department with severe right lower abdominal pain, nausea, vomiting, and anorexia since the day prior to admission. The patient was diagnosed with acute appendicitis, and the pathology report confirmed cytotoxic PTCL of the appendix.

Conclusion

Patients with appendiceal PTCL commonly present with signs and symptoms of acute appendicitis due to luminal obstruction by the tumor. Therefore, appendiceal tumors such as PTCL should be considered in the differential diagnosis of patients presenting as acute appendicitis. In addition, since there is no standard chemotherapy regimen for cytotoxic PTCL, this and other case reports hopefully help in providing the clinical evidence needed for establishing appropriate treatment guidelines.

A rare case of right lower quadrant pain

Endometriosis of the appendix is a very rare entity and commonly affects females in childbearing age. Clinical presentation might be confusing varying from asymptomatic to acute abdominal pain and often mimicks acute appendicitis or chronic pelvic pain. Diagnosis is generally made after pathological examination as operative findings are usually non-specific. This condition poses a diagnostic challenge to radiologists and surgeons altogether and we therefore report a case of a middle aged female who presented with both right lower quadrant and right lower back pain. Recent literature is reviewed and radiological findings discussed.

Clinicopathologic findings in gynecologic proliferations of the appendix

Appendiceal endometriosis, endosalpingiosis, and decidual lesions have received little attention in the pathology literature, meaning their clinicopathologic features remain unclear. We identified 72 cases of appendiceal gynecologic proliferations with available slides. Clinical presentation was recorded when available, and histologic findings were correlated with clinical data. Cases included conventional endometriosis (51), endosalpingiosis (14), and decidual lesions (7). The patients with endosalpingiosis were significantly older (median 45 years) than those with endometriosis (median 34 years, P = .0085) or decidual lesions (median 31 years, P = .0088). Most endometriosis patients presented with known/suspected endometriosis (20/51, 39%), while acute appendicitis was the most common presentation for patients with endosalpingiosis (5/14, 36%) or a decidual lesion (5/7, 71%). Few patients presenting with appendicitis were ever diagnosed with extra-appendiceal disease. All 51 endometriosis cases showed both glands and stroma, and 18 (35%) had hemosiderin. One case progressed to endometrioid adenocarcinoma. Endosalpingiosis was an incidental finding in all cases, confined to the serosa in 4 and extending intramurally in 10. Four of the 7 patients with a decidual lesion were pregnant, and 2 others were taking oral contraceptives. The cases included florid decidualized endometriosis (5) and deciduosis (2). Two cases spread transmurally and effectively obliterated the appendix. Conventional appendiceal endometriosis can have several clinical presentations. Patients with it who present with acute appendicitis rarely develop it elsewhere. Appendiceal endosalpingiosis is rare and effectively incidental. Decidualized endometriosis may overtake the entire appendix.

Ilececum: A Comprehensive Review

For gastrointestinal endoscopists, the ileocecum is the finishing line during colonoscopy and it is identified by three endoscopic landmarks: terminal ileum, ileocecal valve, and the appendiceal orifice. Although ileal intubation is recommended during routine screening colonoscopy, it is not required in most cases of screening colonoscopy. Ileal intubation is indicated in certain circumstances such as suspected inflammatory bowel disease and GI bleeding. There is much pathology that can be observed within the ileocecum. Careful and systematic examination should be stressed during GI endoscopic training and practice. In this review, the authors demonstrate its anatomy, endoscopic findings, and pathologies.

Clinicopathological characteristics and prognosis of primary appendiceal stromal tumors

Background

Gastrointestinal stromal tumors (GISTs) account for less than 1% of all gastrointestinal tumors. The biological behaviors of GISTs vary from benign to malignant. GISTs are common in the stomach (55.6%) and small intestine (31.8%), but rarely in the rectum, colon (6%), and other sites (5.5%). Currently, the majority of published reports of primary appendiceal stromal tumors (PASTs) are case reports or case series.

Methods

The PASTs described in this study were identified from a literature review (23 cases) and our center (one case). The relationship between PAST gross types and clinicopathological factors was analyzed and summarized. At the same time, the study also analyzed the related risk factors and survival of PASTs and GISTs.

Results

Twenty-four cases of PASTs were compared with 254 cases of GISTs from our center. The results showed that there was a significant difference between the two groups in tumor size (P < 0.001), histological type (P = 0.013), CD34 expression (P < 0.001), and DOG-1 expression (P < 0.001). Disease-free survival (DFS) analysis of 11 cases of PASTs and 227 cases of GISTs found that a comparison of 3-year and 5-year DFS was not statistically significant (P = 0.894 and P = 0.846, respectively). In the DFS multivariate analysis, tumor mucosal ulceration, tumor size, and NIH risk classification were independent prognostic factors in 3-year and 5-year DFS.

Conclusion

In this study, there was no significance in the survival of patients with appendix and gastric stromal tumors, which we hypothesized to be associated with the low sample size and incomplete follow-up records. Based on this, we conclude that the prognosis of primary appendiceal stromal tumors may be better than gastric tumors, but this needs to be confirmed in further prospective studies.

Comprehensive review of typical and atypical pathology of the appendix on CT: cases with clinical implications

Acute appendicitis is the most common abdominal surgical emergency in the United States with approximately 250,000 cases annually. Computed Tomography (CT) has emerged as the most accurate diagnostic test to triage these patients for emergent surgery. Although the radiology search pattern is prioritized to detect an inflamed appendix, not all appearances equate to a typical surgical appendicitis. There are a select set of atypical pathologies involving the appendix that have subtle differences on CT, but can have catastrophic complications if treated with emergent appendectomy. This paper will review the spectrum of CT appearances and clinical management for typical and atypical appendiceal pathologies.

Mimicry of Appendicitis Symptomatology in Congenital Anomalies and Diseases of the Genitourinary System and Pregnancy

INTRODUCTION

Appendicitis is a prevailing cause of acute abdomen, but is often difficult to diagnose due to its wide range of symptoms, anatomical variations, and developmental abnormalities. Urological disorders of the genitourinary tract may be closely related to appendicitis due to the close proximity of the appendix to the genitourinary tract. This review provides a summary of the urological complications and simulations of appendicitis. Both typical and urological symptoms of appendicitis are discussed, as well as recommended diagnostic and treatment methods.

METHODS

Medline searches were conducted via PubMed in order to incorporate data from the recent and early literature.

RESULTS

Urological manifestations of appendicitis affect the adrenal glands, kidney, retroperitoneum, ureter, bladder, prostate, scrotum, and penis. Appendicitis in pregnancy is difficult to diagnose due to variations in appendiceal position and trimester-specific symptoms. Ultrasound, CT, and MRI are used in diagnosis of appendicitis and its complications. Treatment of appendicitis may be done via open appendectomy or laparoscopic appendectomy. In some cases, other surgeries are required to treat urological complications, though surgery may be avoided completely in other cases.

CONCLUSION

Clinical presentation and complications of appendicitis vary among patients, especially when the genitourinary tract is involved. Appendicitis may mimic urological disorders and vice versa. Awareness of differential diagnosis and proper diagnostic techniques is important in preventing delayed diagnosis and possible complications. MRI is recommended for diagnosis of pregnant patients. Ultrasound is preferred in patients exhibiting typical symptoms.

Duplicate appendix with acute ruptured appendicitis: a case report

Duplication of the appendix is a rare congenital anomaly that, in adults, is most often found incidentally during surgery for other reasons. Appendicitis in the duplicated appendix is very rare and has been reported less than 10 times in the medical literature. We describe a 33-year-old woman with worsening periumbilical pain, nausea, vomiting, and fever. Physical examination showed localized peritonitis in the right lower quadrant. She had an elevated white blood cell count with neutrophilia. Computed tomography showed acute ruptured appendicitis. Diagnostic laparoscopy showed 2 appendices attached via separate bases to a single cecum with no other concurrent anomalies. Both appendices were removed laparoscopically. Histopathology confirmed normal appendiceal tissue in one and severe acute transmural appendicitis in the other. Awareness of appendiceal duplication and a thorough intraoperative inspection are critical to assess the presence of significant associated anomalies and avoid life-threatening complications.

Beyond appendicitis; radiologic review of unusual and rare pathology of the appendix

Appendicitis is a very common cause of acute abdominal pathology, however, many other pathologic conditions of the appendix can be diagnosed utilizing CT. Examples of these conditions include primary appendiceal neoplasms, secondary inflammation of the appendix, stump appendicitis, endometriosis, appendicitis within a hernia, appendiceal diverticulosis and intussusception and intraluminal foreign bodies. The purpose of this article is to review appendiceal pathology outside of acute appendicitis, describe corresponding imaging findings on CT, and to illustrate various CT findings of appendiceal disease with representative cases.

Acute Appendicitis and Pneumatosis in a Duplicated Appendix With Schistosoma Remnants

Appendiceal pneumatosis is rare, reported either in the context of acute appendicitis or enterocolitis. Here, we report the case of an elderly adult in whom the acute appendicitis was associated with pneumatosis and occurred in the context of a malformed appendix with pathogenic organism remnants. A 72-year-old man presented with abdominal pain 3 weeks after posttraumatic dorsolumbar surgery. The computed tomography scan showed acute appendicitis and 2 diverticula. On microscopy, the appendix showed acute appendicitis along with a Cave-Wallbridge type A duplication. In addition, several optically clear spaces were observed in the entire appendiceal wall consistent with pneumatosis of the appendix. Focally, calcified structures suggesting pathogenic organisms such as Schistosoma were noted as well. In conclusion, we report a case of appendiceal pneumatosis occurring in the context of acute appendicitis in a duplicated appendix, with presence of calcified structures suggestive of pathogenic organisms.

Beyond acute appendicitis: imaging of additional pathologies of the pediatric appendix

Primary acute appendicitis is by far the most common pathological condition affecting the appendix. There are differential diagnoses, however, when an abnormal appendix is found by imaging. The purpose of this paper is to highlight the imaging and clinical manifestations of less common appendiceal abnormalities in children. Familiarity with these alternative diagnoses might be particularly helpful in guiding management of the child whose clinical presentation is not typical for primary acute appendicitis.

The surgical management of a stage III Wilms tumor presenting with perforated appendicitis

The majority of the cases of nephroblastoma do not present with abdominal pain. We present a patient with an acute surgical abdomen due to perforated appendicitis and an incidental abdominal mass. He underwent an urgent appendectomy after which tumor specific therapy was successfully initiated.

Significance of acquired diverticular disease of the vermiform appendix: a marker of regional neoplasms?

AIM

To assess the prevalence of acquired diverticulum of the appendix (DA), including incipient forms and its possible significance as a marker of local/regional neoplasms.

MATERIALS AND METHODS

The pathology database at Hvidovre Hospital was searched for appendix specimens, received between 2001 and 2010, coded for DA or for a space-occupying lesion. Slides were reviewed to determine DA status and the nature of lesions possibly causing DA.

RESULT

Among 4413 appendix specimens, DA were identified in 39 (0.9%, CI 0.6% to 1.2%) cases, 17 (43.6%, 28.0% to 59.2%) of which additionally harboured an appendiceal neoplasm/neoplastic precursor, whereas this figure was 1.2% (CI 0.9% to 1.6%) for non-DA specimens (p<0.0001). Six of the 39 DA specimens comprised incipient DA, three of which coexisted with appendiceal neoplasms. In addition, local/regional non-neoplastic lesions (six cases) and colorectal carcinomas (four cases) coexisted with DA.

CONCLUSION

DA has significance as a putative marker of local/regional neoplasms. Therefore, a DA specimen proved significantly more likely to harbour a neoplastic growth than a non-DA counterpart. Submission for microscopy of the entire DA specimen, whether transmural or only incipient, and a comment in the pathology report on the occasional concurrence of local/regional neoplasms in this setting seem appropriate. The observation of DA may thus provide a valuable contribution in the diagnostic process.

Appendiceal wall thickening at CT in asymptomatic patients with extraintestinal malignancy may mimic appendicitis

The purpose of this study was to describe the CT appearance and determine the prevalence of thick-walled appendices in patients with an extraintestinal primary malignancy. This potential mimic of appendicitis may occur in up to 2% of cancer patients. Awareness of this pitfall is important to avoid unnecessary laparotomy in this patient population.

Gastrointestinal involvement in polyarteritis nodosa

Polyarteritis nodosa (PAN) is a necrotizing, focal segmental vasculitis that affects predominantly medium-sized arteries in many different organ systems. It is associated with hepatitis B virus (HBV) in about 7% of cases, a decline from about 30% before the mandatory testing of blood products and the widespread vaccination programs. HBV PAN is an early postinfectious process. The hepatitis is silent in most cases, with mild transaminase level increases in 50% of patients. Gastrointestinal involvement occurs in 14% to 65% of patients with PAN. Postprandial abdominal pain from ischemia is the most common symptom. When transmural ischemia develops, there may be necrosis of the bowel wall with perforation, associated with a poor prognosis. Liver involvement occurs in 16% to 56% of patients, although clinical manifestations related to liver disease are quite rare. Acalculous gangrenous cholecystitis may develop owing to arteritis involving the wall of the gallbladder. Microaneurysms on arteriography or computed tomography angiography are characteristic of PAN, but are seen in other conditions. Tissue biopsy may confirm the diagnosis, although involvement is segmental. Corticosteroids are used for non-HBV PAN with cyclophosphamide added for severe disease. For PAN related to HBV, a 2-week course of corticosteroids is begun, with plasma exchanges and an antiviral agent. Corticosteroids and cyclophosphamide have improved patient outcome so that the 1-year survival rate is now about 85%.

Diverticular disease of the vermiform appendix: a diagnostic clue to underlying appendiceal neoplasm

Acquired diverticula of the vermiform appendix are rare and arise as a result of different pathogenetic mechanisms. One of the etiologies includes proximally located, often unsuspected small neoplasms. Although the association of appendiceal diverticulosis and neoplasia is known, it remains underemphasized in the teaching and practice of surgical pathology. To investigate the frequency of appendiceal neoplasms with acquired diverticulosis, we conducted a retrospective analysis of all appendectomy specimens received in our institution for a 55-month period (January 2002-July 2006). A total of 1361 appendectomy specimens were identified. Diverticulosis was diagnosed in 23 (1.7%) of all cases. Eleven (48%) appendectomy specimens with diverticulosis also harbored an appendiceal neoplasm. The association of appendiceal neoplasms with diverticulosis was statistically significant (P < .0001, 2-sided Fisher exact test). Neoplastic processes included 5 well-differentiated neuroendocrine tumors (carcinoids), 3 mucinous adenomas, 1 tubular adenoma, and 2 adenocarcinomas. In one case, routine representative sections sampled only a small focus of carcinoma, which originally went undiagnosed. We stress the need for meticulous gross assessment with histologic examination of the entire appendectomy specimen in cases of appendiceal diverticulosis. Thorough examination is required to rule out an underlying neoplasm as a cause of diverticulosis. As acquired diverticula represent a rare finding, examination of the entire appendix in this setting does not create a significant impact on the workload within the pathologic laboratory.

Primary gastrointestinal lymphoma: spectrum of imaging findings with pathologic correlation

Gastrointestinal lymphoma is an uncommon disease but is the most frequently occurring extranodal lymphoma and is almost exclusively of non-Hodgkin type. Primary gastrointestinal lymphoma most commonly involves the stomach but can involve any part of the gastrointestinal tract from the esophagus to the rectum. Risk factors for the development of gastrointestinal lymphoma include Helicobacter pylori infection, immunosuppression after solid organ transplantation, celiac disease, inflammatory bowel disease, and human immunodeficiency virus infection. Although gastrointestinal lymphoma has a wide variety of imaging appearances and definitive diagnosis relies on histopathologic analysis, certain findings (eg, a bulky mass or diffuse infiltration with preservation of fat planes and no obstruction, multiple site involvement, associated bulky lymphadenopathy) can strongly suggest the diagnosis. Imaging also plays an important role in the detection of complications such as perforation, obstruction, and fistulization. The most commonly used imaging modalities are barium examination and computed tomography (CT). These modalities are complementary, although CT provides a better overall assessment of the disease stage.

Gastrointestinal stromal tumor of appendix incidentally diagnosed by appendiceal hemorrhage

Gastrointestinal stromal tumor is rare, which arises from the mesenchymal tissues in the gastrointestinal tract, and it is extremely rare in the appendix. Only a few cases have been found in this location to date. Although the annual incidence of lower gastrointestinal bleeding has been increasing, bleeding related to the appendix is quite rare. We herein present a very rare case of gastrointestinal stromal tumor incidentally found by appendiceal hemorrhage.

Pathology of the appendix in children: an institutional experience and review of the literature

BACKGROUND

The appendix can be affected by a variety of congenital and acquired diseases, but acute appendicitis is the most common pathology found in the pediatric population.

OBJECTIVE

This is a retrospective review of all appendectomies performed during a 2-year period at a major children's hospital with a review of the literature regarding the most common pathologic findings.

MATERIALS AND METHODS

The pathology database was reviewed for appendectomy specimens, and patient medical records were evaluated to determine the age, gender, race and operative diagnosis. All slides were reviewed and the histologic findings were recorded.

RESULTS

A total of 392 appendectomies were performed, including 68 incidental appendectomies and 324 performed for clinical suspicion of acute appendicitis. In 247 of the latter, acute appendicitis was confirmed histologically, and of the remainder 14 were interval appendectomies, 2 had findings suspicious for Crohn disease, 1 confirmed diverticulitis and 60 were histologically negative for appendicitis.

CONCLUSION

Acute appendicitis is the most common pathologic cause of appendectomy, but various other pathologic entities are found in children. Examination of the appendix is warranted even when it appears normal on exploration.

Management of an unexpected appendiceal neoplasm

BACKGROUND

Appendiceal neoplasms are rare and most present unexpectedly as acute appendicitis. The classification and management are confusing, and there are few substantial reports in the literature.

METHODS

A systematic literature review was performed to access relevant publications on the presentation, pathology and management of appendiceal tumours.

RESULTS

Appendiceal tumours account for 0.4 to 1 per cent of all gastrointestinal tract malignancies and are found in 0.7 to 1.7 per cent of appendicectomy specimens. Carcinoid tumours are most common. Most are cured by simple appendicectomy if the tumour is less than 2 cm in size and does not involve the resection margin or mesoappendix. Epithelial tumours may present with, or in time develop, pseudomyxoma peritonei, the optimal management of which involves complete tumour resection and intraperitoneal chemotherapy, usually available only in specialized centres.

CONCLUSION

Suggested algorithms for the management of unexpected appendiceal tumours are provided. Recommendations are made for follow-up of patients with a perforated appendiceal epithelial tumour.