Hepatic granulomas: pathogenesis and differential diagnosis

Hepatic granulomas following liver transplantation: A retrospective survey, and analysis of possible microbiological etiology

BACKGROUND

Liver granulomas have always been a diagnostic challenge for pathologists. They have been described in up to 15% of liver biopsies and can also be seen in liver allograft biopsy specimens, but there is a paucity of information regarding the prevalence and associated etiologic factors of granulomas in liver transplanted patients. The aim of this study is to shed light on the etiology of liver granulomas.

METHODS

Liver biopsies from liver transplanted patients, in the period from 01.01.2011 - 01.05.2017, were examined. We registered the histo-morphological characteristics and clinicopathological data of all biopsies and performed next-generation sequencing (NGS) to detect possible pathogens (bacteria, fungi, and parasites) in the biopsies containing granulomas.

RESULTS

We reviewed a total of 400 liver biopsies from 217 liver transplant patients. Of these, 131 liver biopsies (32.8%) from 98 patients (45.2%) revealed granulomas. Most were epithelioid granulomas located parenchymal and were detected in 115 (87.7%) biopsies. We also identified 10 cases (7.6%) with both lobular and portal granulomas and six biopsies (4.5%) with portal granulomas alone. In 54 biopsies (41.2%), granulomas were found in biopsies with acute cellular rejection (ACR). Fifty (51%) patients with granulomas underwent liver transplantation for autoimmune-related end-stage liver disease (AILD). The granulomas were found most frequently in the first six months after transplantation, where patients also more often were biopsied. NGS analysis did not reveal any potential infectious agent, and no significant differences were observed in the microbiological diversity (microbiome) between clinical- and granuloma characteristics concerning bacteria, fungi, and parasites.

CONCLUSION

Our study confirmed that granulomas are frequently seen in liver allograft biopsy specimens, and most often localized in the parenchyma, occurring in the first post-transplant period in patients with AILD, and often seen simultaneously with episodes of ACR. Neither a specific microbiological etiological agent nor a consistent microbiome was detected in any case.

Hepatic focal lesions and constitutional syndrome, is it always cancer?

Hepatic focal lesions are a heterogeneous group of lesions that can be either benign or malignant in nature. They are typically diagnosed through ultrasound in all cases needing to rule out a metastatic nature. We present the case of a 51-year-old male from Morocco diagnosed with hepatic SOLs in the context of abdominal pain and constitutional syndrome.

Hepatic Sarcoid-Like Reaction Mimicking Liver Metastases in a 36-Year-Old Female With Rheumatoid Arthritis

Hepatic and splenic sarcoidosis are still challenging issues for medical imaging, and in many cases, medical images can't exclude the most common mimic of sarcoidosis which is liver metastases; therefore, a liver biopsy is required. A young female patient who had rheumatoid arthritis presented to our hospital with abdominal pain, anorexia, and weight loss for the past three weeks. She was admitted to the acute medical ward and treated with intravenous fluid hydration for hypercalcemia. Her liver function tests were deranged (anicteric cholestasis picture), and her etanercept medication was stopped after being reviewed by the rheumatologist and gastroenterologist. She had a CT and MRI scan of the abdomen, an ultrasound (US) of the abdomen with enhanced contrast, and a positron emission tomography (PET) scan. The radiological findings could not exclude liver metastases, but an ultrasound-guided liver biopsy confirmed the finding of hepatic granulomatous changes of sarcoidosis. Her symptoms and hypercalcemia resolved, and her liver functions gradually normalized.

A surgical resection of hepatic granuloma mimicking intrahepatic cholangiocarcinoma: a case report

Hepatic granuloma is relatively rare, and benign tumor of the liver. Herein, we report an unusual case of hepatic granuloma mimicking intrahepatic cholangiocarcinoma (ICC). An 82-year-old woman with a history of viral hepatitis B was admitted for investigation of liver mass in the left lobe. Dynamic computed tomography revealed a mostly hypo-enhancing main tumor with a peripheral ring enhancement, and positron emission tomography demonstrated localized an abnormal accumulation of fludeoxyglucose. Considering the possibility of malignant disease, extended left hepatectomy was performed. The resected tumor was macroscopically a periductal infiltrating nodular type, 4.5 × 3.6 cm in diameter. The pathological findings showed that granuloma and coagulative necrosis were present, and diagnosis of hepatic granuloma was confirmed. Pathological studies demonstrated that periodic acid-Schiff stain, Grocott-Gomori stain and Ziehl-Neelsen stain were all negative in the lesion.

[Hepatic granuloma-A diagnostic challenge]

Hepatic granulomas can have various causes and their detection requires a systematic diagnostic evaluation. First, identification of risk factors for granulomatous diseases and the exclusion of extrahepatic organ manifestation are necessary. Laboratory investigations and serological screening for the most common underlying diseases of liver granulomas in Germany, such as primary biliary cholangitis (PBC), sarcoidosis and infectious causes (primarily tuberculosis and hepatitis C infections), are recommended. A liver biopsy is essential for confirming the diagnosis, whereby a minilaparoscopically guided tissue sampling offers many advantages, such as the macroscopic detection of granulomas on the liver surface, on the peritoneum or on the spleen. Whether the detection of hepatic granulomas results in a therapeutic consequence, depends decisively on the underlying primary disease. If hepatic granulomas are present without concomitant liver parenchymal damage or other manifestations that would make treatment necessary, a watch and wait approach under close clinical and laboratory monitoring is sufficient. If liver values increase or in cases of hepatic parenchymal damage, urgent treatment of the underlying disease is indicated.

Focal hepatic intrinsically hyperattenuating lesions at unenhanced CT: Not always calcifications

Due to the growing use of CT, there has been an increase in the frequency of detecting focal liver lesions. Intrinsically hyperattenuating hepatic lesions or pseudolesions are not uncommon at unenhanced CT. Hyperattenuating hepatic lesions can be divided into non-calcified and calcified. Causes of intrinsic hyperattenuation include hemorrhage, thrombosis, and calcifications. Focal liver lesions can show hyperattenuation on unenhanced CT in case of severe liver steatosis. Recognition of etiologies associated with hyperattenuation on unenhanced CT can help the radiologist in characterizing focal liver lesions and pseudolesions. In this paper, we describe the spectrum of intrinsically hyperattenuating focal liver lesions and pseudolesions at unenhanced CT.

Granuloma With an Underlying Lymphoma: A Diagnostic Challenge and a Wider Histologic Spectrum Including Adult T-Cell Leukemia/Lymphoma

Granulomatous reaction is not uncommon in histopathology, with various etiologies in different organs and geographic regions. Lymphoma is one of the underlying causes of granuloma; and sometimes the neoplastic cells may be masked by the granulomatous reaction. In this report, we present our experience with 7 lymphoma cases of various histologic types with coexisting granuloma to show the diagnostic challenges. In all cases, a granulomatous reaction was simultaneously present with the neoplastic cells. The 7 cases included 3 cases of adult T-cell leukemia/lymphoma in the lymph node or skin including one coexisting with mycobacterial infection, 2 cases of classical Hodgkin lymphoma involving the liver, and 1 case each of systemic Epstein-Barr virus-positive peripheral T-cell lymphoma and a hepatic inflammatory pseudotumor-like follicular dendritic cell sarcoma. Three cases were initially misdiagnosed as reactive change or mycobacterial infection instead of lymphoma, and a wrong histologic lymphoma type was diagnosed in 1 case. In this report, we showed that granulomatous reaction might mask lymphomas of various histologic types; and a diagnosis of mycobacterial infection or sarcoidosis could not exclude the possibility of an underlying lymphoma. We emphasized the importance of detailed histologic examination with the aid of ancillary studies to reach a correct diagnosis and to avoid inappropriate management of the patients. Our study also broadened the spectrum of lymphoma types coexisting with granuloma.

Gastrointestinal and Abdominal Tuberculosis

Gastrointestinal (GI) tuberculosis (TB) remains a significant problem worldwide, and may involve the luminal GI tract from oral cavity to perianal area in addition to associated viscera and peritoneum. Although GI TB more commonly affects immunocompromised hosts, it can also occur in immunocompetent people. Diagnosis is difficult because it usually mimics a malignancy or inflammatory bowel disease. A high index of clinical suspicion and appropriate use of combined investigative methods help in early diagnosis, and reduce morbidity and mortality. Anti-TB therapy is the same as for pulmonary disease, and invasive and specialized interventions are reserved for selected complications.

Sarcoidosis: A Clinical Overview from Symptoms to Diagnosis

Sarcoidosis is a multi-system disease of unknown etiology characterized by the formation of granulomas in various organs. It affects people of all ethnic backgrounds and occurs at any time of life but is more frequent in African Americans and Scandinavians and in adults between 30 and 50 years of age. Sarcoidosis can affect any organ with a frequency varying according to ethnicity, sex and age. Intrathoracic involvement occurs in 90% of patients with symmetrical bilateral hilar adenopathy and/or diffuse lung micronodules, mainly along the lymphatic structures which are the most affected system. Among extrapulmonary manifestations, skin lesions, uveitis, liver or splenic involvement, peripheral and abdominal lymphadenopathy and peripheral arthritis are the most frequent with a prevalence of 25-50%. Finally, cardiac and neurological manifestations which can be the initial manifestation of sarcoidosis, as can be bilateral parotitis, nasosinusal or laryngeal signs, hypercalcemia and renal dysfunction, affect less than 10% of patients. The diagnosis is not standardized but is based on three major criteria: a compatible clinical and/or radiological presentation, the histological evidence of non-necrotizing granulomatous inflammation in one or more tissues and the exclusion of alternative causes of granulomatous disease. Certain clinical features are considered to be highly specific of the disease (e.g., Löfgren's syndrome, lupus pernio, Heerfordt's syndrome) and do not require histological confirmation. New diagnostic guidelines were recently published. Specific clinical criteria have been developed for the diagnosis of cardiac, neurological and ocular sarcoidosis. This article focuses on the clinical presentation and the common differentials that need to be considered when appropriate.

Liver rheumatoid nodules imitating liver malignancy: a rare occurrence

We describe a case of a 61-year-old man with a background of rheumatoid arthritis who presented to the emergency department with a single-reported episode of haemoptysis on the background of an upper respiratory tract infection. A CT scan revealed an incidental 40 mm mass in upper right lobe of the liver abutting the diaphragmatic surface. A subsequent positron emission tomography scan confirmed the mass and raised the possibility of another lesion in the liver raising the suspicion of malignancy. The case was complicated by the inability to perform a fine needle aspiration biopsy due to the mass' proximity to the diaphragm. After discussion with the patient, it was decided to resect the affected liver segment. Histological analysis of the mass revealed localised necrotising granulomatous inflammation suggestive of a rheumatoid nodule, which is seldom reported in the literature.

Iatrogenic hepatic granuloma (suspected liver metastatic lesion on imaging) caused by liver retraction during laparoscopic gastrectomy: A case report

There are no previous reports of hepatic granuloma secondary to intraoperative liver retraction. Using softer hepatic retraction instruments and keeping hepatic retraction time to a minimum are vital in preventing postoperative liver damage.

Hepatic Sarcoidosis: Current Concepts and Treatments

Hepatic sarcoidosis is a relatively common manifestation of extrapulmonary sarcoidosis. It occurs in 20 to 30% of cases and is rarely severe. However, a cluster of patients may develop severe complications such as cirrhosis and portal hypertension. In this review, we describe the current knowledge of clinical, biological, pathological, and radiological features of liver involvement in sarcoidosis and discuss essential clues for management and treatment.

Evaluating the risk to humans from mineral oils in foods: Current state of the evidence

Key issues around the evaluation of risks to humans from mineral oils in food and feedstuffs are discussed. MOHs (MOAH and MOSH) occur in food due to intentional use, contamination from environmental sources and during transport/processing, or through migration from food contact materials. Problems in setting and enforcing human health guidelines for MOH include uncertainty around MOH toxicity and the specialist expertise needed for analysis of complex food matrices. Currently, the method of choice for measuring mineral oils is LC-GC-FID, however some complex food matrices also require additional analytical techniques to differentiate between some naturally occurring hydrocarbons and those from other sources, including of petrogenic origin. This requires the skills of an experienced analyst. Significant toxicological gaps for MOHs prevent robust human health risk assessment and the derivation of guidance values. As food-grade mineral oils are virtually MOAH-free, the key issue explored here is the relevance to humans of liver (micro)granulomas observed in F344 rats following oral intake. Available data suggest that despite the ubiquitous nature of MOH in the human diet, the prevalence of liver lipogranulomas in the population is low. These are not associated with inflammation and based on current evidence are not considered of human health significance.

Hepatic Silicone Granulomas Secondary to Ruptured Breast Implants: A Report of Two Cases

The differential diagnosis of hepatic granulomas is vast and includes infections, drugs, immunologic diseases, foreign material exposure, and neoplasia. Silicone, whether directly injected into tissues or used as a filler in breast implants, is known to cause localized granulomatous reactions. It can also migrate to other anatomic locations resulting in granulomatous inflammation at a distance. We report two cases of unsuspected hepatic silicone granulomas in patients undergoing liver biopsy for isolated elevated alkaline phosphatase levels, both with a history of ruptured breast implants. These cases highlight the need for awareness of hepatic silicone granulomas as an etiology of elevated liver enzymes in patients with a history of surgical interventions utilizing silica, such as cosmetic surgery.

Kratom-Induced Cholestatic Liver Injury Mimicking Anti-Mitochondrial Antibody-Negative Primary Biliary Cholangitis: A Case Report and Review of Literature

Kratom is an herbal supplement used to relieve chronic pain or opioid withdrawal symptoms. Recent news articles covering adverse effects associated with kratom use have brought attention to its organ toxicities. Reports of kratom-induced hepatic toxicity are limited and only three case reports of kratom-induced liver injury with histopathologic examination of the liver biopsies are available. A 40-year-old female presented with symptoms of mixed cholestatic and hepatocellular liver injury without clear etiology. The laboratory and imaging workup suggested possibilities of autoimmune hepatitis, autoimmune hepatitis-primary biliary cholangitis (PBC) overlap syndrome, or drug-induced liver injury. Autoantibodies including anti-mitochondrial antibody (AMA) were negative. Liver biopsy showed granulomatous hepatitis with prominent duct injury, suggestive of AMA-negative PBC. She subsequently was referred to a hepatologist and a history of recent kratom use was finally revealed. Kratom was discontinued and the symptoms improved. Kratom-induced hepatic toxicity may manifest with variable biochemical and clinical abnormalities. Histologically, it may mimic AMA-negative PBC. Our case highlights the importance of thorough history taking, interdisciplinary approach and communication for optimal patient care.

Epicardial anthracosis in a patient undergoing coronary artery bypass graft surgery

Anthracosis is an occupational disease which is caused by long-term inhalation of coal and rock dust. We present a case of epicardial anthracosis in a patient who underwent coronary artery bypass graft surgery for coronary artery disease. This is the first case of anthracosis related to the heart in the literature to the best of our knowledge. This case report emphasizes the systemic dissemination of inorganic particles such as carbon in the human body.

Granulomas in the Liver, with a Focus on Infectious Causes

Hepatic granulomas are encountered in approximately 2% to 10% of liver biopsies. There are many potential infectious and noninfectious causes; granulomas can be generally classified by their morphology, which may be helpful in refining the differential diagnosis. This article provides a review of hepatic granulomas with an emphasis on infectious causes.

Hepatic granulomas: a 17-year single tertiary centre experience

AIMS

Hepatic granulomas have an estimated prevalence of 5% in liver biopsies, with a wide range of aetiologies globally. Our aim was to assess the clinical relevance, presenting features and underlying aetiology in a non-transplant, tertiary referral centre from a western country.

METHODS AND RESULTS

This was a retrospective, single-centre review of clinical, laboratory and histological data including all adult patients for whom a liver biopsy was performed from January 1998 to December 2014. A total of 297 cases with hepatic granulomas were found in 9374 biopsies, but 57 were excluded from analysis either because they were lipogranulomas or the biopsy/aetiological work-up had not been performed at our institution. Overall, the most common aetiology was tuberculosis (35.8%), followed by primary biliary cholangitis (PBC) - 15.0%. In 30 patients (12.5%) granulomas were classified as idiopathic. From 1998 to June 2006 there were 147 granulomas in 5304 biopsies (2.8%), a frequency that did not change significantly compared to the period from July 2006 to December 2014 (93 granulomas in 4070 biopsies, 2.3%, P > 0.05). However, for the majority of cases (61.9%) there was a shift in granuloma aetiology during the former time-period that infectious diseases were responsible, whereas in the latter, autoimmune liver diseases (43%) were the main aetiology. In addition, while three cases of drug-induced granulomas were found from 1998 to June 2006, we report two cases in the second time-period.

CONCLUSIONS

Hepatic granulomas can result from various infectious and non-infectious diseases. During recent years, an epidemiological shift regarding granuloma aetiology was observed, from systemic infectious diseases to non-infectious, mainly immune-mediated primary liver disorders. With an appropriate work-up the aetiology can be identified in the vast majority of cases (~90%), rendering its histological identification and characterisation essential, as disease-specific therapies are becoming available.

Disseminated granulomatous hepatitis: A case

Disseminated granulomatous hepatitis is a form of multifocal, disseminated epithelioid granulomatous hepatitis. Granulomatous hepatitis is mostly caused by infection and rarely observed in non-infectious diseases. At present, there have been very few reports of disseminated granulomatous hepatitis in China. Here we report a case of disseminated granuloma hepatitis and analyze its clinical and pathological characteristics and etiology, with an aim to enhance the awareness of this condition.

Hepatic Granulomas: A Review With Emphasis on Infectious Causes

CONTEXT

Many diseases that cause granulomas or granulomatous inflammation involve the liver. Some of these disease processes are intrinsic hepatic diseases, whereas others are disseminated systemic diseases that involve the liver as well as other organs.

OBJECTIVE

To review the evaluation of granulomas in the liver with an emphasis on infectious causes, as well as the use of special stains, serologic studies, and molecular diagnostic techniques. Pertinent noninfectious causes of hepatic granulomas that are in the differential diagnosis are also discussed.

DATA SOURCES

Literature review and cases acquired during years of practice.

CONCLUSIONS

A wide variety of infectious and noninfectious entities cause hepatic granulomas.

An unusual cause of febrile hepatitis

We describe the case of a 51-year-old man with recently diagnosed ulcerative colitis who developed fever and elevated liver enzymes as well as cholestasis a few weeks after starting treatment with mesalazine. As no obvious cause was found and fever persisted, liver biopsy was performed and revealed granulomatous hepatitis. The patient recovered completely after cessation of mesalazine, so that a drug-induced granulomatous hepatitis after exclusion of other differential diagnoses in an extensive work up was assumed. The present case demonstrates that even though drug-induced liver injury due to mesalazine is rare, it should be considered in unclear cases and lead to prompt discontinuation of mesalazine.

A case of typhoid Fever with hepatic granulomas and enteritis

The common histopathologic hepatic manifestations in patients infected with Salmonella include cloudy swelling and balloon degeneration with vacuolation of the hepatocytes and steatosis. Hepatic granulomas are a very rare finding, so far reported in very few cases. We report a 64-year-old patient with Salmonella enteritis who was found to have multiple 1.4 to 1.6 cm hypoechoic liver masses on ultrasound of the abdomen which on biopsy revealed hepatic granulomas. This case highlights the importance of keeping the differential diagnosis of Salmonella typhi (S. typhi) in mind in a patient with hepatic granulomas.

Co-occurrence of idiopathic granulomatous hepatitis and primary biliary cirrhosis

BACKGROUND

PBC is an autoimmune disease affecting the bile ducts. Granulomas can be found in portal triads in 45 % of patients with PBC. Idiopathic granulomatous hepatitis is a rare disease of unknown cause which is characterized by recurrent fevers, sweats, elevated levels of liver enzyme tests, particularly the serum alkaline phosphatase, and granulomas in the portal and lobular regions of the liver. Previous literature suggests that a diagnosis of idiopathic granulomatous hepatitis can be made only if PBC has been excluded.

STUDY

We reviewed instances in which PBC and idiopathic granulomatous hepatitis occurred in the same patient.

RESULTS

We report three patients in whom both diseases occurred: 1) A patient with PBC who was diagnosed 15 years later with idiopathic granulomatous hepatitis; 2) A patient with idiopathic granulomatous hepatitis who developed PBC 12 years later; and 3) A patient who had features of both idiopathic granulomatous hepatitis and PBC at the time of initial diagnosis.

CONCLUSIONS

Our experience with these patients suggests that idiopathic granulomatous hepatitis and PBC can occur in the same individual. Knowing this association is important, as clinical deterioration in a patient with either disease could suggest the presence of the other and should be treated accordingly.

Cat-scratch disease presenting as multiple hepatic lesions: case report and literature review

Although infectious diseases are the most prevalent cause of fevers of unknown origin (FUO), this diagnosis remains challenging in some pediatric patients. Imaging exams, such as computed tomography (CT) are frequently required during the diagnostic processes. The presence of multiple hypoattenuating scattered images throughout the liver associated with the history of cohabitation with cats should raise the suspicion of the diagnosis of cat-scratch disease (CSD), although the main etiologic agent of liver abscesses in childhood is Staphylococcus aureus. Differential diagnosis by clinical and epidemiological data with Bartonella henselae is often advisable. The authors report the case of a boy aged 2 years and 9 months with 16-day history of daily fever accompanied by intermittent abdominal pain. Physical examination was unremarkable. Abdominal ultrasound performed in the initial work up was unrevealing, but an abdominal CT that was performed afterwards disclosed multiple hypoattenuating hepatic images compatible with the diagnosis of micro abscesses. Initial antibiotic regimen included cefotaxime, metronidazole, and oxacillin. Due to the epidemiology of close contact with kittens, diagnosis of CSD was considered and confirmed by serologic tests. Therefore, the initial antibiotics were replaced by clarithromycin orally for 14 days followed by fever defervescence and clinical improvement. The authors call attention to this uncommon diagnosis in a child presenting with FUO and multiple hepatic images suggestive of micro abscesses.

Hepatic Sarcoidosis

Sarcoidosis is a multisystem disease characterized by the presence of non-caseating granulomas in affected organs. Pulmonary involvement is the most common site of disease activity. However, hepatic involvement is also common in sarcoidosis, occurring in up to 70% of patients. Most patients with liver involvement are asymptomatic. Therefore, the majority of cases are discovered incidentally, frequently by the finding of elevated liver enzymes. Pain in the right upper quadrant of the abdomen, fatigue, pruritus, and jaundice may be associated with liver involvement. Portal hypertension and cirrhosis are complications linked to long-standing hepatic sarcoidosis. Liver biopsy is usually required to confirm the diagnosis. It is important to differentiate hepatic sarcoidosis from other autoimmune and granulomatous liver diseases. Not all cases of hepatic sarcoidosis require treatment. For symptomatic patients, the first line treatment includes corticosteroids or ursodeoxycholic acid. Various immunosuppressant agents can be used as second line agents. Rarely, severe cases require liver transplantation.

Hepatic involvement in paediatric patients with paracoccidioidomycosis: a histological study

AIM

Paracoccidioidomycosis is a systemic mycosis that is endemic to certain countries in Latin America. This study aimed to describe the histological features of liver involvement in patients with paracoccidioidomycosis aged <16 years of age who were treated between 1980 and 2010, with a diagnosis that was confirmed by detection of the fungus by pathological examination.

METHODS AND RESULTS

Liver tissue was obtained from one necropsy and 12 biopsies. Throughout 2007, biopsies were taken from patients with persistent jaundice or portal hypertension, after which biopsies became indicated due to elevated aminotransferase and low albumin levels. Using haematoxylin and eosin (H&E), Masson's trichrome and immunohistochemical (CK7 and CK19) staining, we noted degenerative alterations in bile duct cells and inflammatory injury to the bile ducts in 10 biopsies. Using immunohistochemistry for CK7 and CK19, we observed ductal proliferation in all 12 samples.

CONCLUSIONS

Bile duct injuries by inflammatory cells might explain the predominant increase in canalicular enzymes; immunohistochemistry is more sensitive in demonstrating ductular reactions and might show changes that are not apparent on H&E staining.

Atypical mycobacterial infection mimicking metastatic cholangiocarcinoma

Mycobacterial infections are rare in developed countries. Isolated involvement of the liver and biliary tree by mycobacterial infection is extremely rare. We report a case of a 45-year-old Caucasian female presenting with obstructive jaundice with a common bile duct stricture and multiple hypodense liver lesions raising suspicion of a metastatic cholangiocarcinoma. Percutaneous core biopsies of the liver lesions however suggested granulomatous process and histology at surgical excision confirmed this finding. Atypical mycobacteria (M. abcessus) sensitive to Amikacin were cultured from the surgical specimen proving the diagnosis. With the resurgence of tubercular and atypical mycobacterial infections in the developed world, it is important not to overlook these in differential diagnosis of various malignancies.

Detection of microorganisms in granulomas that have been formalin-fixed: review of the literature regarding use of molecular methods

Granuloma is an organized aggregate of immune cells that under the microscope appear as epithelioid macrophages. A granuloma can only be diagnosed when a pathologist observes this type of inflammation under the microscope. If a foreign body or a parasite is not observed inside the granuloma, stains for acid-fast bacilli and fungi are ordered since mycobacteria and fungi are frequently the cause of this type of inflammation. It is calculated that 12 to 36% of granulomas do not have a specific etiology and many have wondered if with new molecular methods we could reduce this number. This paper will summarize the frequently known causes of granulomas and will present the recent literature regarding the use of molecular techniques on tissue specimens and how these have helped in defining causative agents. We will also briefly describe new research regarding formation and function of granulomas and how this impacts our ability to find an etiologic agent.

Hepatocellular adenomas associated with hepatic granulomas: experience in five cases

We present five cases in whom two rare entities were simultaneously found within the liver, i.e. hepatocellular adenomas (HCAs) and granulomas. Coexistence of both entities confuses diagnosis. Our aim is to disclose the association between HCA and hepatic granulomas. Five patients presented with HCA for which they underwent resection. During laparotomy or at pathological examination, granulomas were found in tumorous and non-tumorous tissue. No specific cause for the granulomas was found. Immunohistochemistry showed overexpression of C-reactive protein and serum amyloid A in 4/5 patients, classifying these lesions as inflammatory HCA. HCA and especially the inflammatory subtype may cause formation of granulomas in (peri-)tumorous tissue as a local response to persistent inflammation and/or the presence of a tumor. Both HCA and hepatic granulomas have also been associated with oral contraceptive use. In conclusion, HCAs associated with hepatic granulomas derive from a local response to (inflammatory) HCA or neoplasm, chronic use of oral contraceptives, or a combination of these factors.

The immunopathology of liver granulomas in primary biliary cirrhosis

Liver granulomas and elevated serum IgM are commonly observed in patients with primary biliary cirrhosis (PBC) but their pathogenetic significance remains largely unknown. To address this issue we performed an extensive immunostaining and colocalization study of markers associated with dendritic cells and IgM in a large cohort of tissue samples from PBC and control livers as well as from non-hepatic granulomatous diseases. First, the classical dendritic cell CD11c marker is highly expressed and more sensitive than classical hematoxylin-eosin staining in detecting granulomas associated with PBC and other conditions. Second, PBC cases with CD11c-positive granulomas have significantly higher serum IgM levels and earlier disease stages. Third, granulomas from PBC and other diseases demonstrate markers of dendritic cell immaturity, i.e. CD11b, reduced MHC II, IL-23, CCR7 and CD83 expression, and elevated C1q expression. Lastly, B cells and IgM-positive plasma cells are largely represented around PBC granulomas along with macrophages. In conclusion, our comprehensive immunohistochemical study suggests that dendritic cells are key to the pathogenesis of granulomas, regardless of their origin. More specifically, PBC liver granulomas may result from the interaction between immature dendritic cells and IgM.

Sarcoidosis in a young child with Alagille syndrome: a case report

We report a now 6-year-old African-American male with both Alagille syndrome and pediatric sarcoidosis. With a prior JAG1 mutation positive diagnosis of Alagille syndrome, he presented to the hospital with a subacute, predominantly respiratory febrile condition, eventually diagnosed as sarcoidosis. A liver biopsy revealed paucity of bile ducts and scattered epithelioid granulomas, while a skin biopsy showed granulomatous angiitis, a manifestation of sarcoidosis not yet reported in a pediatric patient. He has subsequently been treated with corticosteroids, mycophenolate mofetil, and infliximab with clinical response. Alagille syndrome and sarcoidosis have not yet been reported in the medical literature in the same patient to the best of our knowledge. We briefly review these two seemingly unrelated conditions and propose a possible common pathogenic mechanism.

Disseminated sarcoidosis presenting as granulomatous gastritis: a clinical review of the gastrointestinal and hepatic manifestations of sarcoidosis

Commonly considered a pulmonary disease, sarcoidosis is actually a multisystemic granulomatous disorder of unclear etiology. There is a wide range of organ system involvement, with gastrointestinal being among the rarest. We describe the diagnostic challenge of a patient presenting with gastritis without pulmonary complaints who was later found to have extrathoracic disseminated sarcoidosis. This case highlighted both the variability in the presentation of the disease and difficulties in its diagnosis. We performed a literature review to identify studies published on gastrointestinal and hepatic sarcoidosis to better understand the characteristics of this disease and help in the differentiation between other commonly encountered disorders that may be mimicked in presentation. We have also created a diagnostic approach that can be applied when endoscopic or hepatic biopsies reveal granulomas. We anticipate that this review may be useful for clinicians who face these diagnostic dilemmas and management decisions for this complex and variable condition.