Multiple imaging modalities may be necessary to evaluate abnormalities of the nipple-areolar complex.

In two studies performed in Japan, high-resolution MRI with a microscopy coil yielding 0.137-mm in-plane resolution has been used to confirm the presence of abscesses, isolated fistulas and inflammation and to reveal their position in order to guide surgery.

The Xanthogranulomatous Process (XP), also known as Xanthogranulomatous Inflammation is a form of acute and chronic inflammation characterized by an exuberant clustering of foamy macrophages among other inflammatory cells. Localization in the kidney and renal pelvis has been the most frequent and better known occurrence followed by that in the gallbladder but many others have been subsequently recorded. The pathological findings of the process and etiopathogenetic and clinical observations have been reviewed by Cozzutto and Carbone.

The xanthogranulomatous type of inflammation is most-commonly seen in pyelonephritis and cholecystitis, although it has more recently been described in an array of other locations including bronchi, lung, endometrium, vagina, fallopian tubes, ovary, testis, epydidymis, stomach, colon, ileum, pancreas, bone, lymph nodes, bladder, adrenal gland, abdomen and muscle. Telling apart clinically a XP from a tumor condition can be challenging as pointed out by several authors. Cozzutto and Carbone suggested that a wide array of entities characterized by a large content of histiocytes and foamy macrophages could be traced back at least in part to a xanthogranulomatous inflammation. These include such varied disturbances as xanthoma disseminatum, ceroid granuloma of the gallbladder, Whipple's disease, inflammatory pseudotumor of the lung, plasma cell granuloma of the lung, malakoplakia, verruciform xanthoma, foamy histiocytosis of the spleen in thrombocytopenic purpura, isolated xanthoma of the small bowel, xanthofibroma of bone, and gastric xanthelasma.

A pathogenetic model might be suggested as follows:

1. suppuration, hemorrhage and necrosis,

2. granulomatous tissue with granular histiocytes and foamy macrophages,

3. fibrohistiocytoma-like or plasma cell granuloma-like patterns,

4. possible myofibroblast metaplasia.

A reactive fibrohistiocytic lesion simulating fibrous histiocytoma has been reported by Snover et al. Reactive granular cells in sites of trauma have been regarded of histiocytic nature. Sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease) might share several aspects of the XP. Likewise there might be some superimpositions between the XP and the plasma cell granuloma/histiocytoma-inflammatory myofibroblastic tumor complex.> The XP might be an important stage of this complex.

Treatment is problematic unless an underlying endocrine disorder can be successfully diagnosed and treated.

A study by Goepel and Panhke provided indications that the inflammation should be controlled by bromocriptine even in absence of hyperprolactinemia.

Antibiotic treatment is given in case of acute inflammation. However, this alone is rarely effective, and the treatment of a subareaolar abscess is primarily surgical. In case of an acute abscess, incision and drainage are performed, followed by antibiotics treatment. However, in contrast to peripheral breast abscess which often resolves after antibiotics and incision and drainage, subareaolar breast abscess has a tendency to recur, often accompanied by the formation of fistulas leading from inflammation area to the skin surface. In many cases, in particular in patients with recurrent subareolar abscess, the excision of the affected lactiferous ducts is indicated, together with the excision of any chronic abscess or fistula. This can be performed using radial or circumareolar incision.

There is no universal agreement on what should be the standard way of treating the condition. In a recent review article, antibiotics treatment, ultrasound evaluation and, if fluid is present, ultrasound-guided fine needle aspiration of the abscess with an 18 gauge needle, under saline lavage until clear, has been suggested as initial line of treatment for breast abscess in puerperal and non-puerperal cases including central (subareolar) abscess (see breast abscess for details). Elsewhere, it has been stated that treatment of subareolar abscess is unlikely to work if it does not address the ducts as such.

Duct resection has been traditionally used to treat the condition; the original Hadfield procedure has been improved many times but long term success rate remains poor even for radical surgery. Petersen even suggests that damage caused by previous surgery is a frequent cause of subareolar abscesses. Goepel and Pahnke and other authors recommend performing surgeries only with concomitant bromocriptine treatment.

As of 2011 five cases had been reported, involving rib, tibial epiphysis, ulna, distal tibia and femur. Young individuals are prevalently affected but one case involved a 50-year-old woman. Pain, swelling of possibly long duration, fever and increased ESR are some of the main clinical findings. X-ray examination shows lytic foci with sclerotic margins. A neoplastic process can be suspected.

In someone suspected of having cholecystitis, blood tests are performed for markers of inflammation (e.g. complete blood count, C-reactive protein), as well as bilirubin levels in order to assess for bile duct blockage. Complete blood count typically shows an increased white blood count (12,000–15,000/mcL). C-reactive protein is usually elevated although not commonly measured in the United States. Bilirubin levels are often mildly elevated (1–4 mg/dL). If bilirubin levels are more significantly elevated, alternate or additional diagnoses should be considered such as gallstone blocking the common bile duct (common bile duct stone). Less commonly, blood aminotransferases are elevated. The degree of elevation of these laboratory values may depend on the degree of inflammation of the gallbladder.

The granulomas of tuberculosis tend to contain necrosis ("caseating tubercules"), but non-necrotizing granulomas may also be present. Multinucleated giant cells with nuclei arranged like a horseshoe (Langhans giant cell) and foreign body giant cells are often present, but are not specific for tuberculosis. A definitive diagnosis of tuberculosis requires identification of the causative organism by microbiologic cultures.

Aspiration pneumonia is typically caused by aspiration of bacteria from the oral cavity into the lungs, and does not result in the formation of granulomas. However, granulomas may form when food particles or other particulate substances like pill fragments are aspirated into the lungs. Patients typically aspirate food because they have esophageal, gastric or neurologic problems. Intake of drugs that depress neurologic function may also lead to aspiration. The resultant granulomas are typically found around the airways (bronchioles) and are often accompanied by foreign-body-type multinucleated giant cells, acute inflammation or organizing pneumonia. The finding of food particles in lung biopsies is diagnostic.

Right upper quadrant abdominal ultrasound is most commonly used to diagnose cholecystitis. Ultrasound findings suggestive of acute cholecystitis include gallstones, fluid surrounding the gallbladder, gallbladder wall thickening (wall thickness over 3 mm), dilation of the bile duct, and sonographic Murphy's sign. Given its higher sensitivity, hepatic iminodiacetic acid (HIDA) scan can be used if ultrasound is not diagnostic. CT scan may also be used if complications such as perforation or gangrene are suspected.

The best imaging modality for idiopathic orbital inflammatory disease is contrast-enhanced thin section magnetic resonance with fat suppression. The best diagnostic clue is a poorly marginated, mass-like enhancing soft tissue involving any area of the orbit.

Overall, radiographic features for idiopathic orbital inflammatory syndrome vary widely. They include inflammation of the extraocular muscles (myositis) with tendinous involvement, orbital fat stranding, lacrimal gland inflammation and enlargement (dacryoadenitis), involvement of the optic sheath complex, uvea, and sclera, a focal intraorbital mass or even diffuse orbital involvement. Bone destruction and intracranial extension is rare, but has been reported. Depending on the area of involvement, IOI may be categorized as:

- Myositic

- Lacrimal

- Anterior – Involvement of the globe, retrobulbar orbit

- Diffuse – Multifocal intraconal involvement with or without an extraconal component

- Apical – Involving the orbital apex and with intracranial involvement

Tolosa–Hunt syndrome is a variant of orbital pseudotumor in which there is extension into the cavernous sinus through the superior orbital fissure. Another disease variant is Sclerosing pseudotumor, which more often presents bilaterally and may extend into the sinuses.

CT findings

In non-enhanced CT one may observe a lacrimal, extra-ocular muscle, or other orbital mass. It may be focal or infiltrative and will have poorly circumscribed soft tissue. In contrast-enhanced CT there is moderate diffuse irregularity and enhancement of the involved structures. A dynamic CT will show an attenuation increase in the late phase, contrary to lymphoma where there is an attenuation decrease. Bone CT will rarely show bone remodeling or erosion, as mentioned above.

MR findings

On MR examination there is hypointensity in T1 weighted imaging (WI), particularly in sclerosing disease. T1WI with contrast will show moderate to marked diffuse irregularity and enhancement of involved structures. T2 weighted imaging with fat suppression will show iso- or slight hyperintensity compared to muscle. There is also decreased signal intensity compared to most orbital lesions due to cellular infiltrate and fibrosis. In chronic disease or sclerosing variant, T2WI with FS will show hypointensity (due to fibrosis). Findings on STIR (Short T1 Inversion Recovery) are similar to those on T2WI FS. In Tolosa–Hunt syndrome, findings include enhancement and fullness of the anterior cavernous sinus and superior orbital fissure in T1WI with contrast, while MRA may show narrowing of cavernous sinus internal carotid artery (ICA).

Ultrasonographic findings

On grayscale ultrasound there is reduced reflectivity, regular internal echoes, and weak attenuation, in a way, similar to lymphoproliferative lesions.

Xanthogranulomatous pyelonephritis is an unusual form of chronic pyelonephritis characterized by granulomatous abscess formation, severe kidney destruction, and a clinical picture that may resemble renal cell carcinoma and other inflammatory kidney parenchymal diseases. Most affected individuals present with recurrent fevers and urosepsis, anemia, and a painful kidney mass. Other common manifestations include kidney stones and loss of function of the affected kidney. Bacterial cultures of kidney tissue are almost always positive. Microscopically, there are granulomas and lipid-laden macrophages (hence the term "xantho"-, which means yellow in ancient Greek). It is found in roughly 20% of specimens from surgically managed cases of pyelonephritis.

If a kidney stone is suspected (e.g. on the basis of characteristic colicky pain or the presence of a disproportionate amount of blood in the urine), a kidneys, ureters, and bladder x-ray (KUB film) may assist in identifying radioopaque stones. Where available, a noncontrast helical CT scan with 5 millimeter sections is the diagnostic modality of choice in the radiographic evaluation of suspected nephrolithiasis. All stones are detectable on CT scans except very rare stones composed of certain drug residues in the urine. In patients with recurrent ascending urinary tract infections, it may be necessary to exclude an anatomical abnormality, such as vesicoureteral reflux or polycystic kidney disease. Investigations used in this setting include kidney ultrasonography or voiding cystourethrography. CT scan or kidney ultrasonography is useful in the diagnosis of xanthogranulomatous pyelonephritis; serial imaging may be useful for differentiating this condition from kidney cancer.

Ultrasound findings that indicate pyelonephritis are enlargement of the kidney, edema in the renal sinus or parenchyma, bleeding, loss of corticomedullary differentiation, abscess formation, or an areas of poor blood flow on doppler ultrasound. However, ultrasound findings are seen in only 20% to 24% of people with pyelonephritis.

A DMSA scan is a radionuclide scan that uses dimercaptosuccinic acid in assessing the kidney morphology. It is now the most reliable test for the diagnosis of acute pyelonephritis.

Xanthogranulomatous osteomyelitis (XO) is a peculiar aspect of osteomyelitis characterized by prevalent histiocytic infiltrate and foamy macrophage clustering.

"Duct ectasia" in the literal sense (literally: duct widening) is a very common and thus rather unspecific finding, increasing with age. However, in the way in which the term is mostly used, duct ectasia is an inflammatory condition of the larger-order lactiferous ducts. It considered likely that the condition is associated with aseptic (chemical) inflammation related to the rupture of ducts or cysts. It is controversial whether duct dilation occurs first and leads to secretory stasis and subsequent periductal inflammation or whether inflammation occurs first and leads to an inflammatory weakening of the duct walls and then stasis. When the inflammation is complicated by necrosis and secondary bacterial infection, breast abscesses may form. Subareolar abscess, also called Zuska's disease (only nonpuerperal case), is a frequently aseptic inflammation and has been associated with squamous metaplasia of the lactiferous ducts.

The duct ectasia—periductal mastitis complex affects two groups of women: young women (in their late teens and early 20s) and perimenopausal women. Women in the younger group mostly have inverted nipples due to squamous metaplasia that lines the ducts more extensively compared to other women and produces keratin plugs which in turn lead to duct obstruction and then duct dilation, secretory stasis, inflammation, infection and abscess. This is not typically the case for women in the older group; in this group, there is likely a multifactorial etiology involving the balance in estrogen, progesterone and prolactin.

Treatment of mastitis and/or abscess in nonlactating women largely the same as that of lactational mastitis, generally involving antibiotics treatment, possibly surgical intervention by means of fine-needle aspiration and/or incision and drainage and/or interventions on the lactiferous ducts (for details, "see also" the articles on treatment of mastitis, of breast abscess and of subareolar abscess). Additionally, an investigation for possible malignancy is needed, normally by means of mammography, and a pathological investigation such as a biopsy may be necessary to exclude malignant mastitis. Although no "causal" relation with breast cancer has been established, there appears to be an increased statistical risk of breast cancer, warranting a long-term surveillance of patients diagnosed with non-puerperal mastitis.

Nonpuerperal breast abscesses have a higher rate of recurrence compared to puerperal breast abscesses. There is a high statistical correlation of nonpuerperal breast abscess with diabetes mellitus (DM). On this basis, it has recently been suggested that diabetes screening should be performed on patients with such abscess.

The diagnosis of DPB requires analysis of the lungs and bronchiolar tissues, which can require a lung biopsy, or the more preferred high resolution computed tomography (HRCT) scan of the lungs. The diagnostic criteria include severe inflammation in all layers of the respiratory bronchioles and lung tissue lesions that appear as nodules within the terminal and respiratory bronchioles in both lungs. The nodules in DPB appear as opaque lumps when viewed on X-rays of the lung, and can cause airway obstruction, which is evaluated by a pulmonary function test, or PFT. Lung X-rays can also reveal dilation of the bronchiolar passages, another sign of DBP. HRCT scans often show blockages of some bronchiolar passages with mucus, which is referred to as the "tree-in-bud" pattern. Hypoxemia, another sign of breathing difficulty, is revealed by measuring the oxygen and carbon dioxide content of the blood, using a blood test called arterial blood gas. Other findings observed with DPB include the proliferation of lymphocytes (white blood cells that fight infection), neutrophils, and foamy histiocytes (tissue macrophages) in the lung lining. Bacteria such as "H. influenzae" and "P. aeruginosa" are also detectable, with the latter becoming more prominent as the disease progresses. The white blood, bacterial and other cellular content of the blood can be measured by taking a complete blood count (CBC). Elevated levels of IgG and IgA (classes of immunoglobulins) may be seen, as well as the presence of rheumatoid factor (an indicator of autoimmunity). Hemagglutination, a clumping of red blood cells in response to the presence of antibodies in the blood, may also occur. Neutrophils, beta-defensins, leukotrienes, and chemokines can also be detected in bronchoalveolar lavage fluid injected then removed from the bronchiolar airways of individuals with DPB, for evaluation.

IOI or orbital pseudotumor is the second most common cause of exophthalmos following Grave’s orbitopathy and the third most common orbital disorder following thyroid orbitopathy and lymphoproliferative disease accounting for 5–17.6% of orbital disorders, There is no age, sex, or race predilection, but it is most frequently seen in middle-aged individuals. Pediatric cases account for about 17% of all cases of IOI.

FDG positron emission tomography (PET) may be useful to detect the condition early. Other imaging studies including MRI, CT scans, and X-rays may reveal inflammation and/or damaged cartilage facilitating diagnosis.

Atherosclerosis, formerly considered a bland lipid storage disease, actually involves an ongoing inflammatory response. Recent advances in basic science have established a fundamental role for inflammation in mediating all stages of this disease from initiation through progression and, ultimately, the thrombotic complications of atherosclerosis. These new findings provide important links between risk factors and the mechanisms of atherogenesis. Clinical studies have shown that this emerging biology of inflammation in atherosclerosis applies directly to human patients. Elevation in markers of inflammation predicts outcomes of patients with acute coronary syndromes, independently of myocardial damage. In addition, low-grade chronic inflammation, as indicated by levels of the inflammatory marker C-reactive protein, prospectively defines risk of atherosclerotic complications, thus adding to prognostic information provided by traditional risk factors. Moreover, certain treatments that reduce coronary risk also limit inflammation. In the case of lipid lowering with statins, this anti-inflammatory effect does not appear to correlate with reduction in low-density lipoprotein levels. These new insights into inflammation in atherosclerosis not only increase our understanding of this disease but also have practical clinical applications in risk stratification and targeting of therapy for this scourge of growing worldwide importance.

A prospective study in 1994 noted that body mass index remains the strongest predictor of symptomatic gallstones among young women. Other risk factors are having over four pregnancies, weight gain, and cigarette smoking. Alcohol was shown to have an inverse relationship between use and gallbladder disease.

Inflammation (from Latin "") is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants, and is a protective response involving immune cells, blood vessels, and molecular mediators. The function of inflammation is to eliminate the initial cause of cell injury, clear out necrotic cells and tissues damaged from the original insult and the inflammatory process, and initiate tissue repair.

The classical signs of inflammation are heat, pain, redness, swelling, and loss of function. Inflammation is a generic response, and therefore it is considered as a mechanism of innate immunity, as compared to adaptive immunity, which is specific for each pathogen. Too little inflammation could lead to progressive tissue destruction by the harmful stimulus (e.g. bacteria) and compromise the survival of the organism. In contrast, chronic inflammation may lead to a host of diseases, such as hay fever, periodontitis, atherosclerosis, rheumatoid arthritis, and even cancer (e.g., gallbladder carcinoma). Inflammation is therefore normally closely regulated by the body.

Inflammation can be classified as either "acute" or "chronic". "Acute inflammation" is the initial response of the body to harmful stimuli and is achieved by the increased movement of plasma and leukocytes (especially granulocytes) from the blood into the injured tissues. A series of biochemical events propagates and matures the inflammatory response, involving the local vascular system, the immune system, and various cells within the injured tissue. Prolonged inflammation, known as "chronic inflammation", leads to a progressive shift in the type of cells present at the site of inflammation, such as mononuclear cells, and is characterized by simultaneous destruction and healing of the tissue from the inflammatory process.

Inflammation is not a synonym for infection. Infection describes the interaction between the action of microbial invasion and the reaction of the body's inflammatory response — the two components are considered together when discussing an infection, and the word is used to imply a microbial invasive cause for the observed inflammatory reaction. Inflammation on the other hand describes purely the body's immunovascular response, whatever the cause may be. But because of how often the two are correlated, words ending in the suffix "" (which refers to inflammation) are sometimes informally described as referring to infection. For example, the word "urethritis" strictly means only "urethral inflammation", but clinical health care providers usually discuss urethritis as a urethral infection because urethral microbial invasion is the most common cause of urethritis.

It is useful to differentiate inflammation and infection as there are many pathological situations where inflammation is not driven by microbial invasion – for example, atherosclerosis, type III hypersensitivity, trauma, ischaemia. There are also pathological situations where microbial invasion does not result in classic inflammatory response—for example, parasitosis, eosinophilia.

Biopsy of the cartilage tissue (for example, ear) may show tissue inflammation and destruction, and may help with the diagnosis. The Biopsy of cartilage in patients with relapsing polychondritis may demonstrate chondrolysis, chondritis, and perichondritis.

Adenitis is a general term for an inflammation of a gland. Often it is used to refer to lymphadenitis which is the inflammation of a lymph node.

The term nonpuerperal mastitis describes inflammatory lesions of the breast (mastitis) that occur unrelated to pregnancy and breastfeeding.

It is sometimes equated with duct ectasia, but other forms can be described.

Histologically, ECD differs from Langerhans cell histiocytosis (LCH) in a number of ways. Unlike LCH, ECD does not stain positive for S-100 proteins or Group 1 CD1a glycoproteins, and electron microscopy of cell cytoplasm does not disclose Birbeck granules. Tissue samples show xanthomatous or xanthogranulomatous infiltration by lipid-laden or foamy histiocytes, and are usually surrounded by fibrosis. Bone biopsy is said to offer the greatest likelihood of reaching a diagnosis. In some, there is histiocyte proliferation, and on staining, the section is CD68+ and CD1a-.

Radiologic osteosclerosis and histology are the main diagnostic features. Diagnosis can often be difficult because of the rareness of ECD as well as the need to differentiate it from LCH. A diagnosis from neurological imaging may not be definitive. The presence of symmetrical cerebellar and pontine signal changes on T2-weighted images seem to be typical of ECD, however, multiple sclerosis and metabolic diseases must also be considered in the differential diagnosis. ECD is not a common cause of exophthalmos but can be diagnosed by biopsy. However, like all biopsies, this may be inconclusive. Video-assisted thoracoscopic surgery may be used for diagnostic confirmation and also for therapeutic relief of recurrent pericardial fluid drainage.