Gastric polyposis caused by multifocal histiocytosis X

Isolated Langerhans cell histiocytosis in the stomach of adults: four-case series and literature review

Langerhans cell histiocytosis (LCH) of the stomach is rare. Moreover, it is usually found in pediatric patients with systemic diseases and may be associated with a poor prognosis. Solitary gastric LCH in adults is extremely rare and is often misdiagnosed or missed. The aim of our study was to review cases of gastric LCH and explore the characteristics of the disease further. A retrospective study of all patients admitted with solitary gastric LCH was conducted between 2013 and 2023. Clinical manifestations, endoscopic and pathological features, immunophenotypes, and molecular changes were collected from medical records. We examined four cases (one female, three males) of gastric LCH. The affected patients were between 33 and 70 years of age. Endoscopically, three patients presented with a solitary polyp or elevated lesions, whereas one patient showed no abnormalities. Under a microscope, all cases showed abnormal proliferation of histiocytoid cells infiltrating in a nested or sheet-like fashion. The tumor cells were medium-sized, with a slightly eosinophilic cytoplasm, irregular or renal-shaped nuclei, folded nuclear membranes, visible nuclear grooves, and the infiltration of inflammatory cells in the background. Immunohistochemically, all lesions expressed CD1a, S-100, langerin, and cyclinD1. One case showed diffuse BRAF V600E positivity. Follow-up data were available for all patients from 4 to 36 months, and all patients were alive without recurrence or progress at the time of manuscript preparation. Combined with previously reported data, solitary adult gastric LCH is more common in male patients, most of whom are asymptomatic or exhibit only mild gastrointestinal symptoms, with a good prognosis. Endoscopy often reveals solitary polyps or protruding lesions; rare cases may progress to multifocal/multisystem lesions, necessitating long-term close follow-up.

Incidental Gastric Langerhans Cell Histiocytosis and Synchronous Adenocarcinoma of the Colon: An Interesting Case Report and Literature Review

BACKGROUND/AIM

Langerhans cell histiocytosis (LCH) is an uncommon disorder characterized by an abnormal monoclonal proliferation of pathologic Langerhans cells. The clinical presentation of LCH is very unpredictable, ranging from single-system limited disease to severe multi-organ disease with a high mortality rate. LCH usually affects children and very rarely adults. The most common body parts affected by LCH are the bones, skin, lungs, pituitary glands, and lymph nodes. Gastrointestinal tract involvement by LCH is exceptionally rare, and only a few cases have been reported.

CASE REPORT

We present the case of a 50-year-old woman who was referred to our clinic by her primary care physician for an upper endoscopy and colonoscopy and was diagnosed with H. pylori-related gastritis and a synchronous gastric LCH and primary colonic adenocarcinoma. We describe the histologic characteristics and clinical implications of the LCH diagnosis. A review of the published literature revealed that LCH presenting as a gastric solitary lesion is rare.

CONCLUSION

This case highlights the importance of recognizing this rare condition to ensure proper patient follow-up.

Gastrointestinal lesion in adult-onset Langerhans cell histiocytosis

BACKGROUND

Langerhans cell histiocytosis (LCH) is a rare disease primarily occurring in children, and commonly involves the bone and skin; gastrointestinal tract involvement is notably rare. The incidence and significance of gastrointestinal lesions in adult LCH are unclear; thus, we aimed to investigate adult Japanese cases of LCH and clarify the features of gastrointestinal involvement.

METHODS

We gathered clinical information on 43 Japanese cases of adult LCH and analyzed patient backgrounds, affected organs, features of the gastrointestinal lesions, and the clinical courses.

RESULTS

Thirteen patients underwent endoscopic examinations: an upper gastrointestinal endoscopy alone in 5, lower gastrointestinal endoscopy alone in 3, and both in 5 patients. A gastric lesion (one case), colonic lesion (one case), and both gastric and rectal lesions (one case) were detected. The three cases of gastrointestinal involvement also exhibited nongastrointestinal multisystem LCH lesions and showed no gastrointestinal symptoms or increased uptake on positron emission tomography. Endoscopy revealed small erosions without specific features; histological examinations were required for diagnosis. These three cases were treated with chemotherapy, comprising vinblastine/prednisolone, methotrexate, and daily 6-mercaptopurine, for 36 weeks; in two cases, the clinical condition remained stable for several years post-treatment. One case showed recurrence 1 year 7 months after treatment, and chemotherapy was re-administered. No case with single-system disease exhibited gastrointestinal involvement.

CONCLUSIONS

Although gastrointestinal LCH lesions are rare, they were more common than expected in our cases of multisystem LCH. However, these lesions were relatively small and did not affect the patients' clinical courses.

Upper Gastrointestinal Langerhans Cell Histiocytosis: A Report of 2 Adult Cases and a Literature Review

Langerhans cell histiocytosis (LCH) with primary involvement of the upper gastrointestinal (GI) tract is rare. We report 2 adult cases of localized LCH in the upper-GI tract, including the second reported adult case of esophageal LCH and review 11 previously reported cases. Case 1 involved the esophagus of a 61-year-old man; histiocytosis was detected when endoscopy was performed for an examination of epigastric pain. Case 2 involved the stomach of a 56-year-old woman wherein the lesion was detected during a follow-up endoscopy after Helicobacter pylori infection. Both biopsy specimens exhibited diffuse proliferation of mononuclear cells with nuclear convolution and a background of eosinophilic infiltrate. The cells were immunohistochemically positive for CD1a and langerin, and BRAF V600E mutation was detected in Case 2. Follow-up endoscopy for both cases revealed that the lesions disappeared without any treatment. It is important to avoid misdiagnosing LCH of the upper-GI tract as a malignant neoplasm.

Merkel cell polyomavirus and Langerhans cell neoplasm

BACKGROUND

The relationship between various external agents such as pollen, food, and infectious agents and human sensitivity exists and is variable depending upon individual's health conditions. For example, we believe that the pathogenetic potential of the Merkel cell polyomavirus (MCPyV), the resident virus in skin, is variable and depends from the degree of individual's reactivity. MCPyV as well as Epstein-Barr virus, which are normally connected with humans under the form of subclinical infection, are thought to be involved at various degrees in several neoplastic and inflammatory diseases. In this review, we cover two types of Langerhans cell neoplasms, the Langerhans cell sarcoma (LCS) and Langerhans cell histiocytosis (LCH), represented as either neoplastic or inflammatory diseases caused by MCPyV.

METHODS

We meta-analyzed both our previous analyses, composed of quantitative PCR for MCPyV-DNA, proteomics, immunohistochemistry which construct IL-17 endocrine model and interleukin-1 (IL-1) activation loop model, and other groups' data.

RESULTS

We have shown that there were subgroups associated with the MCPyV as a causal agent in these two different neoplasms. Comparatively, LCS, distinct from the LCH, is a neoplastic lesion (or sarcoma) without presence of inflammatory granuloma frequently observed in the elderly. LCH is a proliferative disease of Langerhans-like abnormal cells which carry mutations of genes involved in the RAS/MAPK signaling pathway. We found that MCPyV may be involved in the development of LCH.

CONCLUSION

We hypothesized that a subgroup of LCS developed according the same mechanism involved in Merkel cell carcinoma pathogenesis. We proposed LCH developed from an inflammatory process that was sustained due to gene mutations. We hypothesized that MCPyV infection triggered an IL-1 activation loop that lies beneath the pathogenesis of LCH and propose a new triple-factor model.

Interleukin-1 loop model for pathogenesis of Langerhans cell histiocytosis

We propose Langerhans cell histiocytosis (LCH) is an inflammatory process that is prolonged by mutations. We hypothesize that Merkel cell polyomavirus (MCPyV) infection triggers an interleukin-1 (IL-1) activation loop that underlies the pathogenesis of LCH. Langerhans cells (LCs) are antigen presenting cells in the skin. When LCs encounter exogenous antigens, they migrate from the epidermis into draining lymphoid tissues to initiate T-cell activity. It has been proposed that LC migration-related factors, including E-cadherin, matrix metalloproteinase, and Notch ligand induce LCH activity. We found that the tyrosine phosphatase SHP-1, which binds IL-1 receptor-associated kinase 1, is expressed at a significantly higher level in LCH affecting multiple organ systems (MS-LCH) than in LCH affecting a single organ system (SS-LCH). IL-1 stimulates T helper 17 cells and their signature cytokine IL-17 had been a matter of controversy. We detected higher levels of IL-17A receptor expression in MS-LCH than in SS-LCH and proposed an IL-17 endocrine model that could settle the controversy. IL-1 is the first cytokine secreted in response to sensitizers and promotes LC migration from sentinel tissues. Myeloid differentiation primary response 88 (MyD88), downstream of the IL-1 receptor, has functions in both RAS signaling and inflammation, leading to human cell transformation. In 2010, an activating mutation in the B-rapidly accelerated fibrosarcoma gene (BRAF) V600E was found in LCH. This BRAF mutation induces phosphorylation of the extracellular signal-regulated kinase (ERK) that may play an important role with MyD88 in LCH pathogenesis. However, phosphorylated ERK (pERK) is rapidly dephosphorylated by dual specificity phosphatase 6 (DUSP6), and limited proliferation is predicted in BRAF mutant cells. MyD88 binds pERK via its D-domain, thereby preventing pERK–DUSP6 interaction and maintaining ERK in an active, phosphorylated state. We detected MCPyV-DNA in the peripheral blood cells of two out of three patients with LCH in high-risk organs but not in those of patients with LCH in non–high-risk organs (0/12; P = .029). MCPyV infection can trigger precursor LCH cells with BRAF mutation to produce IL-1; the IL-1 loop is amplified in all LCH subclasses. Our model indicates both BRAF mutation and IL-1 loop regulation as potential therapeutic targets.

A rare case of langerhans cell histiocytosis of the gastrointestinal tract

Langerhans cell histiocytosis (LCH) is a group of idiopathic disorders characterized by the proliferation of specialized, bone marrow-derived langerhans cells and mature eosinophils. The clinical spectrum ranges from an acute, fulminant, disseminated disease called Letterer-Siwe disease to solitary or few, indolent and chronic lesions of the bone or other organs called eosinophilic granuloma. Involvement of the gastrointestinal tract is very rare in LCH. We present the case of a 53-year-old woman referred by her primary care physician for a screening colonoscopy. A single sessile polyp, measuring 4 mm in size, was found in the rectum. Histopathological examination revealed that the lesion was relatively well circumscribed and comprised mainly a mixture of polygonal cells with moderate-to-abundant pink slightly granular cytoplasm. The nuclei within these cells had frequent grooves and were occasionally folded. Immunohistochemical staining was positive for CD-1a which confirmed the diagnosis of LCH. On further workup, there was no evidence of involvement of any other organ. On follow up colonoscopy one year later, there was no evidence of disease recurrence. Review of the published literature revealed that LCH presenting as solitary colonic polyp is rare. However, with the increasing rates of screening colonoscopy, more colonic polyps may be identified as LCH on histopathology. This underscores the importance of recognizing this rare condition and ensuring proper follow-up to rule out systemic disease.

Gastrointestinal polyposis in childhood: clinicopathologic and genetic features

Gastrointestinal polyps and certain extraintestinal lesions in children may herald a hereditary polyposis syndrome, with an increased risk of neoplasia and other health problems for both children and their relatives. The availability of molecular/genetic screening tests has increased early diagnosis of younger members of known polyposis families. This article reviews the gross and microscopic features of polyposis syndromes of childhood and summarizes the molecular/genetic advances in this field. Clinical management is also briefly discussed.

Langerhans cell histiocytosis of the stomach with atypical morphological features

We report the unique case of a 52-year-old patient with atypical morphological features of gastric Langerhans cell histiocytosis. The man was admitted because of increasing upper abdominal pain and weight loss. The upper gastrointestinal endoscopy showed a submucous, hemispherical tumor of the stomach wall along the lesser curvature. The tumor was completely removed and the patient was discharged 11 days later. Two months later, he died at home. The cause of death is unknown, because the autopsy was denied by the relatives. Macroscopically, the stomach showed a 4.5 x 2.5 cm large, spherical tumor of the lesser curvature of the corpus, which infiltrated the perigastric omenta and lymph nodes, the distal pancreas and the glissonian liver capsule. The vast majority of neoplastic cells were intensely positive for S-100 and CD1a. Typical Birbeck granules could be identified in almost all cells. Cell nuclei analyzed by flow cytometry showed an aneuploid peak, a feature typically associated with malignant disease.

CD68+ reactive histiocytosis complicating early gastric cancer

A peculiar form of reactive, non-granulomatous proliferation of CD68+ histiocytes was demonstrated, for the first time, in the submucosal layer just beneath the IIa-type early gastric adenocarcinoma that focally invaded submucosal lymphatics. The histiocytic cells possessed plump eosinophilic and often foamy cytoplasm and eccentric small nuclei with apparent nucleoli. They contained periodic acid-Schiff-reactive granules, and were further immunoreactive for lysozyme and alpha 1-antitrypsin. The infiltration was ill-defined, and partly involved the tunica muscularis mucosae and the proper muscle layer. Markers of epithelial cells, Langerhans' histiocytes, smooth muscle cells and myofibroblasts were all negative.