1)positive tuberclin test

2)chest radiograph

3)CT scan

4)cytology/biopsy (FNAC)

5)AFB staining

6)mycobacterial culture

Incision drainage with proper evacuation of the fluid followed by anti-tubercular medication.

Testing for miliary tuberculosis is conducted in a similar manner as for other forms of tuberculosis, although a number of tests must be conducted on a patient to confirm diagnosis. Tests include chest x-ray, sputum culture, bronchoscopy, open lung biopsy, head CT/MRI, blood cultures, fundoscopy, and electrocardiography. The tuberculosis (TB) blood test, also called an Interferon Gamma Release Assay or IGRA, is a way to diagnose latent TB.

A variety of neurological complications have been noted in miliary tuberculosis patients—tuberculous meningitis and cerebral tuberculomas being the most frequent. However, a majority of patients improve following antituberculous treatment. Rarely lymphangitic spread of lung cancer could mimic miliary pattern of tuberculosis on regular chest X-ray.

The tuberculin skin test, commonly used for detection of other forms of tuberculosis, is not useful in the detection of miliary tuberculosis. The tuberculin skin test fails due to the high numbers of false negatives. These false negatives may occur because of higher rates of tuberculin anergy compared to other forms of tuberculosis.

lymphadenopathy is a common biopsy finding, and may often be confused with malignant lymphoma. It may be separated into major morphologic patterns, each with its own differential diagnosis with certain types of lymphoma. Most cases of reactive follicular hyperplasia are easy to diagnose, but some cases may be confused with follicular lymphoma. There are seven distinct patterns of benign lymphadenopathy:

- Follicular hyperplasia: This is the most common type of reactive lymphadenopathy.

- Paracortical hyperplasia/Interfollicular hyperplasia: It is seen in viral infections, skin diseases, and nonspecific reactions.

- Sinus histiocytosis: It is seen in lymph nodes draining limbs, inflammatory lesions, and malignancies.

- Nodal extensive necrosis

- Nodal granulomatous inflammation

- Nodal extensive fibrosis (Connective tissue framework)

- Nodal deposition of interstitial substance

These morphological patterns are never pure. Thus, reactive follicular hyperplasia can have a component of paracortical hyperplasia. However, this distinction is important for the differential diagnosis of the cause.

Diagnosis can be achieved through blood cultures, or cultures of other bodily fluids such as sputum. Bone marrow culture can often yield an earlier diagnosis, but is usually avoided as an initial diagnostic step because of its invasiveness.

Many people will have anemia and neutropenia if bone marrow is involved. MAC bacteria should always be considered in a person with HIV infection presenting with diarrhea.

The diagnosis requires consistent symptoms with two additional signs:

- Chest X-ray or CT scan showing evidence of right middle lobe (or left lingular lobe) lung infection

- Sputum culture or bronchoalveolar lavage culture demonstrating the infection is caused by MAC

Disseminated MAC is most readily diagnosed by one positive blood culture. Blood cultures should be performed in patients with symptoms, signs, or laboratory abnormalities compatible with mycobacterium infection. Blood cultures are not routinely recommended for asymptomatic persons, even for those who have CD4+ T-lymphocyte counts less than 100 cells/uL.

The differential diagnosis of Rosai–Dorfman disease includes both malignant and nonmalignant diseases, such as granulomatosis with polyangiitis, Langerhans cell histiocytosis, Langerhans cell sarcoma, lymphoma, sarcoidosis, and tuberculosis. The disease is diagnosed by biopsy of affected tissues. Microscopic examination of stained specimens will show histiocytes with lymphocytes and possibly other types of cells trapped within them, a phenomenon known as emperipolesis. Upon immunohistochemical staining, the histiocytes will be positive for S100, CD68, and CD163 but negative for CD1a.

If left untreated, miliary tuberculosis is almost always fatal. Although most cases of miliary tuberculosis are treatable, the mortality rate among children with miliary tuberculosis remains 15 to 20% and for adults 25 to 30%. One of the main causes for these high mortality rates includes late detection of disease caused by non-specific symptoms. Non-specific symptoms include: coughing, weight loss, or organ dysfunction. These symptoms may be implicated in numerous disorders, thus delaying diagnosis. Misdiagnosis with tuberculosis meningitis is also a common occurrence when patients are tested for tuberculosis, since the two forms of tuberculosis have high rates of co-occurrence.

The diagnosis is confirmed by a skin biopsy and a positive culture for acid-fast bacilli. A PPD test may also result positive.

This is a group of tests that use polymerase chain reaction (PCR) to detect mycobacterial nucleic acid. These test vary in which nucleic acid sequence they detect and vary in their accuracy. The two most common commercially available tests are the amplified mycobacterium tuberculosis direct test (MTD, Gen-Probe) and Amplicor. In 2007, review concluded that for diagnosing tuberculous meningitis "Individually, the AMTD test appears to perform the best (sensitivity 74% and specificity 98%)", they found the pooled prevalence of TB meningitis to be 29%.

MAC in patients with HIV disease is theorized to represent recent acquisition rather than latent infection reactivating (which is the case in many other opportunistic infections in immunocompromised patients).

The risk of MAC is inversely related to the patient's CD4 count, and increases significantly when the CD4 count decreases below 50 cells/mm³. Other risk factors for acquisition of MAC infection include using an indoor swimming pool, consumption of raw or partially cooked fish or shellfish, bronchoscopy and treatment with granulocyte stimulating factor.

Disseminated disease was previously the common presentation prior to the advent of highly active antiretroviral therapy (HAART). Today, in regions where HAART is the standard of care, localized disease presentation is more likely. This generally includes a focal lymphadenopathy/lymphadenitis.

Lymph node enlargement is recognized as a common sign of infectious, autoimmune, or malignant disease. Examples may include:

- Reactive: acute infection ("e.g.," bacterial, or viral), or chronic infections (tuberculous lymphadenitis, cat-scratch disease).

- The most distinctive sign of bubonic plague is extreme swelling of one or more lymph nodes that bulge out of the skin as "buboes." The buboes often become necrotic and may even rupture.

- Infectious mononucleosis is an acute viral infection caused by Epstein-Barr virus and may be characterized by a marked enlargement of the cervical lymph nodes.

- It is also a sign of cutaneous anthrax and Human African trypanosomiasis

- Toxoplasmosis, a parasitic disease, gives a generalized lymphadenopathy ("Piringer-Kuchinka lymphadenopathy").

- Plasma cell variant of Castleman's disease - associated with HHV-8 infection and HIV infection

- Mesenteric lymphadenitis after viral systemic infection (particularly in the GALT in the appendix) can commonly present like appendicitis.

Less common infectious causes of lymphadenopathy may include bacterial infections such as cat scratch disease, tularemia, brucellosis, or prevotella.

- Tumoral:

- Primary: Hodgkin lymphoma and non-Hodgkin lymphoma give lymphadenopathy in all or a few lymph nodes.

- Secondary: metastasis, Virchow's Node, neuroblastoma, and chronic lymphocytic leukemia.

- Autoimmune: systemic lupus erythematosus and rheumatoid arthritis may have a generalized lymphadenopathy.

- Immunocompromised: AIDS. Generalized lymphadenopathy is an early sign of infection with human immunodeficiency virus (HIV), the virus that causes acquired immunodeficiency syndrome (AIDS). "Lymphadenopathy syndrome" has been used to describe the first symptomatic stage of HIV progression, preceding a diagnosis of AIDS.

- Bites from certain venomous snakes such as the pit viper

- Unknown: Kikuchi disease, progressive transformation of germinal centers, sarcoidosis, hyaline-vascular variant of Castleman's disease, Rosai-Dorfman disease, Kawasaki disease, Kimura disease

X-rays can be used to examine the lung tissue, however it can not be used to positively diagnose geotrichosis. X-rays may show cavitation that is located the walls of the lungs tissues. The lung tissue resemble the early signs of tuberculosis. The results of an x-ray examination of pulmonary geotrichosis presents smooth, dense patchy infiltrations and some cavities. Bronchial geotrichosis shows peribronchial thickening with fine mottling may be present on middle or basilar pulmonary fields. Bronchial geotrichosis usually present itself as non-specific diffuse peribronchical infiltration.

Diagnosis of TB meningitis is made by analysing cerebrospinal fluid collected by lumbar puncture. When collecting CSF for suspected TB meningitis, a minimum of 1ml of fluid should be taken (preferably 5 to 10ml). The CSF usually has a high protein, low glucose and a raised number of lymphocytes. Acid-fast bacilli are sometimes seen on a CSF smear, but more commonly, "M. tuberculosis" is grown in culture. A spiderweb clot in the collected CSF is characteristic of TB meningitis, but is a rare finding. ELISPOT testing is not useful for the diagnosis of acute TB meningitis and is often false negative, but may paradoxically become positive after treatment has started, which helps to confirm the diagnosis.

Some patients have no symptoms, spontaneous remission, or a relapsing/remitting course, making it difficult to decide whether therapy is needed. In 2002, authors from Sapienza University of Rome stated on the basis of a comprehensive literature review that "clinical observation without treatment is advisable when possible."

Therapeutic options include surgery, radiation therapy, and chemotherapy. Surgery is used to remove single lymph nodes, central nervous system lesions, or localized cutaneous disease. In 2014, Dalia and colleagues wrote that for patients with extensive or systemic Rosai–Dorfman disease, "a standard of care has not been established" concerning radiotherapy and chemotherapy.

The diagnosis of the condition is made on the basis of histological and bacteriological studies. Tuberculosis dactylitis may be confused with conditions like osteomyelitis, gout, sarcoidosis and tumors.

A CT scan provides a computer-generated picture of the lungs that can show pockets of fluid. It also may show signs of pneumonia, a lung abscess, or a tumor.

The diagnoses of geotrichosis cannot be determined without using culture or microscopic measurements. The laboratory diagnosis of geotrichosis involves collected fungi samples areas of infections without contamination. Scraping of the mouth lesions and the ulcers can provide a sample of "G. candidum." Samples can also be collected from pus and mucus can be obtained from the feces. Sputum can be searched for the mucoid-like white flakes for further examination. Culturing the cylindrical barrel-shaped or elliptical fungi in considerable numbers in oral lesions is an indicator that a patient may have geotrichosis. Under the microscope the fungi appears yeast-like and septate branching hyphae that can be broken down into chains or individual arthrospores. Arthrospores appear rectangular with flat or rounded ends. Under the microscope the arthroconidia size range from 6-12μm x 3-6μm. Arthroconidia and coarse true hyphae can be observed can be observed under the microscope. Another identification method for "G. candidum" is selective isolation method. A selection isolation method based on the fungi tolerance to novobiocin and carbon dioxide can determine if "G. candidum" is the cause of illness.

Diagnosis of mycetoma is usually established clinically in endemic areas.

X rays and ultrasonography may be employed in evaluating the extent of the disease. X rays findings are extremely variable. The disease is most often observed at an advanced stage that exhibits extensive destruction of all bones of the foot. Rarely, a single lesion may be seen in the tibia where the picture is identical with chronic osteomyelitis. Cytology of fine needle aspirate or pus from the lesion, and tissue biopsy may be undertaken sometimes. Some publications have claimed a "dot in a circle sign" as a characteristic MRI feature for this condition (this feature has also been described on ultrasound).

In arterial blood-gas sampling, a small amount of blood is taken from an artery, usually in the wrist. The blood is then checked for oxygen and carbon-dioxide levels. This test shows how well the lungs are taking in oxygen.

Diagnosis is often made by visualization of yeast cells in tissue, or superficial scrapings. Radiography of the chest reveals interstitial infiltrates in the majority of cases.

Once a pleural effusion is diagnosed, its cause must be determined. Pleural fluid is drawn out of the pleural space in a process called thoracentesis, and it should be done in almost all patients who have pleural fluid that is at least 10 mm in thickness on CT, ultrasonography, or lateral decubitus X-ray and that is new or of uncertain etiology. In general, the only patients who do not require thoracentesis are those who have heart failure with symmetric pleural effusions and no chest pain or fever; in these patients, diuresis can be tried, and thoracentesis is avoided unless effusions persist for more than 3 days. In a thoracentesis, a needle is inserted through the back of the chest wall in the sixth, seventh, or eighth intercostal space on the midaxillary line, into the pleural space. The use of ultrasound to guide the procedure is now standard of care as it increases accuracy and decreases complications. After removal, the fluid may then be evaluated for:

1. Chemical composition including protein, lactate dehydrogenase (LDH), albumin, amylase, pH, and glucose

2. Gram stain and culture to identify possible bacterial infections

3. White and red blood cell counts and differential white blood cell counts

4. Cytopathology to identify cancer cells, but may also identify some infective organisms

5. Other tests as suggested by the clinical situation – lipids, fungal culture, viral culture, tuberculosis cultures, lupus cell prep, specific immunoglobulins

Tuberculous gumma (also known as a "metastatic tuberculous abscess" and "metastatic tuberculous ulcer") is a cutaneous condition characterized histologically by massive necrosis. Restated, this is a skin condition that results from hematogenous dissemination of mycobacteria from a primary focus, resulting in firm, nontender erythematous nodules that soften, ulcerate, and form sinuses.

A study conducted on 452 patients revealed that the genotype responsible for higher IL-10 expression makes HIV infected people more susceptible to tuberculosis infection. Another study on HIV-TB co-infected patients also concluded that higher level of IL-10 and IL-22 makes TB patient more susceptible to Immune reconstitution inflammatory syndrome (IRIS). It is also seen that HIV co-infection with tuberculosis also reduces concentration of immunopathogenic matrix metalloproteinase (MMPs) leading to reduced inflammatory immunopathology.

The following clinical conditions may be considered before diagnosing a patient with mycetoma:

1. Tuberculous ulcer

2. Kaposi's sarcoma, a vascular tumour of skin usually seen in AIDS.

3. Leprosy

4. Syphilis

5. Malignant neoplasm

6. Tropical ulcer

7. Botryomycosis, a skin infection usually caused by the bacteria Staphylococcus aureus.

A pleural effusion appears as an area of whiteness on a standard posteroanterior chest X-ray. Normally, the space between the visceral pleura and the parietal pleura cannot be seen. A pleural effusion infiltrates the space between these layers. Because the pleural effusion has a density similar to water, it can be seen on radiographs. Since the effusion has greater density than the rest of the lung, it gravitates towards the lower portions of the pleural cavity. The pleural effusion behaves according to basic fluid dynamics, conforming to the shape of pleural space, which is determined by the lung and chest wall. If the pleural space contains both air and fluid, then an air-fluid level that is horizontal will be present, instead of conforming to the lung space. Chest radiographs in the lateral decubitus position (with the patient lying on the side of the pleural effusion) are more sensitive and can detect as little as 50 mL of fluid. At least 300 mL of fluid must be present before upright chest X-rays can detect a pleural effusion (e.g., blunted costophrenic angles).

Chest computed tomography is more accurate for diagnosis and may be obtained to better characterize the presence, size, and characteristics of a pleural effusion. Lung ultrasound, nearly as accurate as CT and more accurate than chest X-ray, is increasingly being used at the point of care to diagnose pleural effusions, with the advantage that it is a safe, dynamic, and repeatable imaging modality. To increase diagnostic accuracy of detection of pleural effusion sonographically, markers such as boomerang and VIP signs can be utilized.