PTGC is usually characterized by localized lymphadenopathy and is otherwise typically asymptomatic.

Dermatopathic lymphadenopathy is diagnosed by a lymph node biopsy. It has a characteristic pattern of histomorphology and immunohistochemical staining:

- Paracortical histiocytosis

- Melanin-laden macrophages

- Eosinophils

- Plasma cells (medulla of lymph node)

Patients with this disease usually present at an advanced stage and show systemic involvement. The clinical findings typically include a pruritic skin rash and possibly edema, ascites, pleural effusions, and arthritis.

Lymphadenopathy of the axillary lymph nodes can be defined as solid nodes measuring more than 15 mm without fatty hilum. Axillary lymph nodes may be normal up to 30 mm if consisting largely of fat.

.Letterer-Siwe is characterized by skin lesions, ear drainage, lymphadenopathy, osteolytic lesions, and hepatosplenomegaly. The skin lesions are scaly and may involve the scalp, ear canals, and abdomen.

The histiocytosis of Rosai–Dorfman disease can occur in lymph nodes, causing lymphadenopathy, or can occur outside lymph nodes in extranodal disease.

Lymphadenopathy can occur in one or more groups of lymph nodes. Among 358 cases of Rosai–Dorfman disease that Rosai collected in a disease registry for which the location of lymphadenopathy was specified, 87.3% had cervical lymphadenopathy. Axillary, inguinal, and mediastinal lymphadenopathy are also found in Rosai–Dorfman disease.

PTGC is diagnosed by surgical excision of the affected lymph node(s), and examination by a pathologist. The differential diagnosis includes non-neoplastic causes of lymphadenopathy (e.g. cat-scratch fever, Kikuchi disease) and malignancy, i.e. cancer.

Lymphadenopathy or adenopathy is disease of the lymph nodes, in which they are abnormal in size, number, or consistency. Lymphadenopathy of an inflammatory type (the most common type) is lymphadenitis, producing swollen or enlarged lymph nodes. In clinical practice, the distinction between lymphadenopathy and lymphadenitis is rarely made and the words are usually treated as synonymous. Inflammation of the lymphatic vessels is known as lymphangitis. Infectious lymphadenitides affecting lymph nodes in the neck are often called scrofula.

The term comes from the word lymph and a combination of the Greek words , "adenas" ("gland") and , "patheia" ("act of suffering" or "disease").

Lymphadenopathy is a common and nonspecific sign. Common causes include infections (from minor ones such as the common cold to dangerous ones such as HIV/AIDS), autoimmune diseases, and cancers. Lymphadenopathy is also frequently idiopathic and self-limiting.

In pathology, dermatopathic lymphadenopathy, also dermatopathic lymphadenitis, is lymph node pathology due to skin disease.

Atypical infections are the key clinical manifestation of SGD. Within the first few years of life, patients will experience repeated pyogenic infections by species such as "Staphylococcus aureus", "Pseudomonas aeruginosa" or other Enterobacteriaceae, and "Candida albicans". Cutaneous ulcers or abscesses and pneumonia and chronic lung disease are common. Patients may also develop sepsis, mastoiditis, otitis media, and lymphadenopathy. Infants may present with vomiting, diarrhea, and failure to thrive.

Diagnosis can be made based upon CEBPE gene mutation or a pathognomonic finding of a blood smear showing lack of specific granules. Neutrophils and eosinophils will contain hyposegmented nuclei (a pseudo-Pelger–Huet anomaly).

Due to the systemic nature of this disease, neoplastic cells can be found in lymph nodes, liver, spleen, skin, and bone marrow.

The disease is often rapidly fatal, with a five year survival rate of 50%. The development of thrombocytopenia is a poor prognostic sign.

Bilateral hilar lymphadenopathy is a bilateral enlargement of the lymph nodes of pulmonary hila. It is a radiographic term that describes the enlargement of mediastinal lymph nodes and is most commonly identified by a chest x-ray.

IPMs present as painless lymphadenopathy. They usually are found in the inguinal region and grow slowly.

The signs and symptoms are non-specific, i.e. it is not possible to diagnose an IPM from the symptoms and manner in which they present.

The main (clinical) differential diagnosis of IPM is metastatic cancer, e.g. squamous cell carcinoma, malignant melanoma, adenocarcinoma.

Follicular hyperplasia (or "reactive follicular hyperplasia" or "lymphoid nodular hyperplasia") is a type of lymphoid hyperplasia. It is caused by a stimulation of the B cell compartment. It is caused by an abnormal proliferation of secondary follicles and occurs principally in the cortex without broaching the lymph node capsule. The follicles are cytologically polymorphous, are often polarized, and vary in size and shape. Follicular hyperplasia is distinguished from follicular lymphoma in its polyclonality and lack of bcl-2 protein expression, whereas follicular lymphoma is monoclonal, and does express bcl-2).

Acute megakaryoblastic leukemia (AMKL) is a form of leukemia where a majority of the blasts are megakaryoblastic.

It is classified under AML-M7 category of the French-American-British classification.

The latest WHO classification (2008, Lyon), classifies Acute Myeloid Leukemia into distinct subtypes, based on clinico-pathological and molecular features. Acute megakaryoblastic leukemia is placed under the AML-Not Otherwise Specified subcategory.

Diagnosis requires more than 20% Blasts in the marrow/ peripheral blood with more than 50% demonstrating megakaryocytic derivation by morphology, immunophenotypic or electron microscopic studies.

Neutrophil-specific granule deficiency (SGD, previously known as lactoferrin deficiency) is a rare congenital immunodeficiency characterized by an increased risk for pyogenic infections due to defective production of specific granules and gelatinase granules in patient neutrophils.

Patients usually present with constitutional symptoms (malaise, weight loss, fatigue), and hepatosplenomegaly is commonly found on physical exam. Lymphadenopathy is also found to a lesser extent. Due to the aggressive nature of the disease, patients may initially present at a more advanced stage, with coagulopathies, hemophagocytic syndrome, and multi-organ failure.

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.

Intranodal palisaded myofibroblastoma, abbreviated IPM, is a rare primary tumour of lymph nodes, that classically presents as an inguinal mass.

It afflicts predominantly males of middle age.

The hallmark clinical and laboratory features include high fever, hepatosplenomegaly, lymphadenopathy, pancytopenia, liver dysfunction, disseminated intravascular coagulation, hypofibrinogenemia, hyperferritinemia, and hypertriglyceridemia. Despite marked systemic inflammation, the erythrocyte sedimentation rate (ESR) is paradoxically depressed, caused by low fibrinogen levels. The low ESR helps to distinguish the disorder from a flare of the underlying rheumatic disorder, in which case the ESR is usually elevated. A bone marrow biopsy or aspirate usually shows hemophagocytosis.

Some specific reactive lymphadenopathies with a predominantly follicular pattern:

- Rheumatoid arthritis

- Sjogren syndrome

- IgG4-related disease (IgG4-related lymphadenopathy)

- Kimura disease

- Toxoplasmosis

- Syphilis

- Castleman disease

- HIV-associated lymphadenopathy

- Progressive transformation of germinal centers (PTGC)

Mediastinal lymphadenopathy or mediastinal adenopathy is an enlargement of the Mediastinal lymph nodes

The following are causes of BHL:

- Sarcoidosis

- Infection

- Tuberculosis

- Fungal infection

- Mycoplasma

- Intestinal Lipodystrophy (Whipple's disease)

- Malignancy

- Lymphoma

- Carcinoma

- Mediastinal tumors

- Inorganic dust disease

- Silicosis

- Berylliosis

- Extrinsic allergic alveolitis

- Such as bird fancier's lung

- Less common causes also exist:

- Eosinophilic granulomatosis with polyangiitis

- Human immunodeficiency virus

- Extrinsic allergic alveolitis

- Adult-onset Still's disease