Anaplastic large cell lymphoma overview

# Overview
Anaplastic large cell lymphoma is an aggressive (fast-growing) type of non-Hodgkin lymphoma that is usually of the T-cell type. ALK negative ALCL T-cells express CD30 but do not express the ALK (Anaplastic Lymphoma Kinase) chimeric protein. Anaplastic lymphoma kinase positive large B-cell lymphoma (ALK+ LBCL) was first described in 1997 by Delsol. In 2008, the World Health Organization (WHO) added anaplastic lymphoma kinase (ALK) negative anaplastic large cell lymphoma and anaplastic lymphoma kinase positive large B-cell lymphoma as provisional entities in the peripheral T-cell lymphoma classification. Anaplastic large cell lymphoma may be classified into several sub-types based on immunophenotype.

# Historical Perspective
Anaplastic lymphoma kinase positive large B-cell lymphoma (ALK+ LBCL) was first described in 1997 by Delsol. In 2008, the World Health Organization (WHO) added anaplastic lymphoma kinase (ALK) negative anaplastic large cell lymphoma and anaplastic lymphoma kinase positive large B-cell lymphoma as provisional entities in the peripheral T-cell lymphoma classification.

# Classification
Anaplastic large cell lymphoma may be classified into several sub-types based on immunophenotype, clinical presentation, and histology.

# Pathophysiology
The ALK gene is involved in the pathogenesis of ALK positive anaplastic large cell lymphoma. The DUSP22  gene is involved in the pathogenesis of ALK negative anaplastic large cell lymphoma. On microscopic histopathological analysis, medium-sized cells, abundant cytoplasm, kidney shaped nuclei, and paranuclear eosinophilic region are characteristic findings of anaplastic large cell lymphoma.

# Causes
There are no established causes for anaplastic large cell lymphoma.

# Differential Diagnosis
Anaplastic large cell lymphoma must be differentiated from other diseases such as metastatic carcinoma, B cell lymphoma, primary cutaneous T-cell lymphoma, rhabdomyosarcoma, peripheral T-cell lymphoma-not otherwise specified, classical Hodgkin's lymphoma, and diffuse large B cell lymphoma.

# Epidemiology and Demographics
Anaplastic large cell lymphoma is a common disease that tends to affect children or young adults. Males are more commonly affected with anaplastic large cell lymphoma than females.

# Risk Factors
There are no established risk factors for anaplastic large cell lymphoma.

# Screening
According to the the U.S. Preventive Service Task Force (USPSTF), there is insufficient evidence to recommend routine screening for anaplastic large cell lymphoma.

# Prognosis
The ALK-positive anaplastic large cell lymphoma is associated with the most favorable prognosis. ALK-positive anaplastic large cell lymphoma is associated with a 5 year survival rate of 70-80%. ALK-positive anaplastic large cell lymphoma is associated with a 5 year survival rate of 30-40%.

# Diagnosis

## Staging
According to the Lugano classification, there are four stages of anaplastic large cell lymphoma based on the number of nodes and extranodal involvement.

## Symptoms
The most common symptoms of anaplastic cell lymphoma include fever, weight loss, skin rash, night sweats, chest pain, abdominal pain, bone pain, and painless swelling in the neck, axilla, groin, thorax, and abdomen.

## Physical examination
Common physical examination findings of mantle cell lymphoma include fever, rash, ulcer, splenomegaly, hepatomegaly, chest tenderness, abdomen tenderness, bone tenderness, peripheral lymphadenopathy, and central lymphadenopathy.

## Laboratory tests
Laboratory tests for anaplastic large cell lymphoma include complete blood count (CBC), blood chemistry studies, flow cytometry, FISH, immunohistochemistry, and immunophenotyping.

## Chest X ray
Chest X ray may be helpful in the diagnosis of anaplastic large cell lymphoma. Findings on chest X ray, suggestive of anaplastic large cell lymphoma include pulmonary nodules and pleural effusion.

## CT Scan
Thorax CT scans may be helpful in the diagnosis of anaplastic large cell lymphoma. Findings on CT scans suggestive of anaplastic large cell lymphoma include mediastinal lymphadenopathy and bilateral pleural effusion.

## MRI Scan
Thorax MRI scans may be helpful in the diagnosis of anaplastic large cell lymphoma. Findings on MRI scans suggestive of anaplastic large cell lymphoma include large heterogenous, lobulated mass, and lymphadenopathy.

## Biopsy
Lymph node or extranodal tissue biopsy is diagnostic of anaplastic large cell lymphoma.

## Ultrasound
Abdomen and shoulder ultrasound may be helpful in the diagnosis of anaplastic large cell lymphoma.

## Other Imaging Studies
PET scans may be helpful in the diagnosis of anaplastic large cell lymphoma.

## Other Diagnostic Studies
Other diagnostic studies for anaplastic large cell lymphoma include laparoscopy, laparotomy, bone marrow aspiration, and bone marrow biopsy.

# Treatment

## Medical Therapy
The predominant therapy for anaplastic lymphoma is chemotherapy. Adjunctive radiotherapy, stem cell transplantation, and surgery may be required. The optimal therapy for anaplastic large cell lymphoma depends on the type and extent of anaplastic large cell lymphoma.

## Surgery
The feasibility of surgery depends on the type of anaplastic large cell lymphoma.