Small cell lymphoma
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Maria Fernanda Villarreal, M.D. [2]
Synonyms and keywords: Small cell lymphocytic leukemia; SLL
Overview
Small cell lymphoma (also known as SLL) is a type of mature B-cell chronic lymphocytic leukemia that presents primarily in the lymph nodes. Small cell lymphoma was first discovered by Dr. George Minot, an American physician, in 1924.[1] There is no classification system for small cell lymphoma. The pathogenesis of small cell lymphoma is characterized by the malignant infiltration of lymphocytic cells into the bone marrow, where they interfere with the production of red blood cells and platelets. Small cell lymphoma arises from pre-follicular center B cells that are normally involved in the process of human immunoglobulins production. Small cell lymphoma represents 90 % of all B-cell chronic lymphocytic leukemias in the United States. Small cell lymphoma is more commonly observed among young adults and middle aged adults. Males are slightly more affected with small cell lymphoma than females. Symptoms of small cell lymphoma may include the following: fever weight loss, generalized weakness, anorexia, and night sweats. The mainstay of therapy for small cell lymphoma is chemotherapy and radiotherapy.
Historical Perspective
Small cell lymphoma was first discovered by Dr. George Minot, an American physician, in 1924.[1]
Classification
There is no classification system for small cell lymphoma.[2] Small cell lymphoma is a subtype of of B-cell chronic lymphocytic leukemia.
Pathophysiology
Pathogenesis
- The pathogenesis of small cell lymphoma is characterized by the malignant infiltration of lymphocytic cells into the bone marrow, where they interfere with the production of red blood cells and platelets.
- Small cell lymphoma arises from pre-follicular center B cells that are normally involved in the process of human immunoglobulins production.
Genetics
Genes involved in the development of small cell lymphoma include:
- Chromosome 11 long arm deletion
- Chromosome 13 long arm deletion (most common genetic mutation)
- Chromosome 17 short arm deletion
- Trisomy 12
Gross Pathology
There are no remarkable gross pathological findings in small cell lymphoma.
Microscopic Pathology
On microscopic histopathological analysis, characteristic findings of small cell lymphoma include:
- Small lymphoid cells
- Thin cytoplasmic border
- Dense nucleus
- Lack of nucleolus
- Clumped chromatin aggregates
- The presence of smudge cells
- The presence of gumprecht nuclear shadows
On immunohistopathological analysis, characteristic findings of small cell lymphoma may include:
Causes
There are no established causes for small cell lymphoma.
Differentiating Small Cell Lymphoma from Other Diseases
Small cell lymphoma must be differentiated from other diseases that cause fever, anorexia, and weakness such as:[3]
Epidemiology and Demographics
Prevalence
The prevalence of small cell lymphoma is low. Small cell lymphoma represents 90 % of all B-cell chronic lymphocytic leukemias in the United States.[3]
Age
The median age at diagnosis is 65 years. Small cell lymphoma is more commonly observed among young adults and middle aged adults.
Gender
Males are more commonly affected with small cell lymphoma than females.
Race
There is no racial predilection for small cell lymphoma.
Risk Factors
Common risk factors in the development of small cell lymphoma include:[3]
- Male gender
- Positive family history
- Exposure to certain chemicals
Natural History, Complications and Prognosis
Natural History
The majority of patients with small cell lymphoma are symptomatic. Early clinical features include generalized weakness, anorexia, and night sweats. If left untreated, patients with small cell lymphoma may progress to develop recurrent infections.
Complications
Common complications of small cell lymphoma include:[3]
- Severe immunodeficiency
- Warm autoimmune hemolytic anemia
- Richter's transformation
Prognosis
Prognosis is generally poor; the 5-year survival rate of patients with small cell lymphoma is approximately 51-67%.[3]
Diagnosis
Symptoms
Symptoms of small cell lymphoma may include the following:
- Fever
- Weight loss
- Muscle wasting
- Generalized weakness
- Anorexia
- Night sweats
Physical Examination
Patients with small cell lymphoma often appear pale and malnourished. Physical examination may be remarkable for:
- Pallor
- Petechiae
- Leukemia cutis (infiltration of neoplastic leukocytes or their precursors into the skin resulting in clinically identifiable cutaneous lesions)
- Enlarged and palpable cervical lymph nodes
- Dacryoadenitis
Laboratory Findings
Laboratory findings consistent with the diagnosis of small cell lymphoma include:[4]
- Absolute lymphocytosis (>5000 cells/μl)[5][6]
- Decreased hemoglobin concentration
- Decreased platelets count
Imaging Findings
There are no specific imaging findings associated with small cell lymphoma. CT scan may be helpful in the diagnosis small cell lymphoma, findings may include enlarged lymph nodes (>2 cm).
Treatment
Medical Therapy
- The mainstay of therapy for small cell lymphoma is chemotherapy and radiotherapy.
Surgery
- Surgery is not recommended among patients with small cell lymphoma.[3]
- The diagnosis of small cell lymphoma is made with a excisional lymph node biopsy combined with a bone marrow biopsy.
Prevention
- There are no primary preventive measures available for small cell lymphoma.
- Once diagnosed and successfully treated, patients with small cell lymphoma are followed-up every 6 or 12 months.
- Periodical follow-up testing include complete blood count and physical examination.
References
- ↑ 1.0 1.1 Rai KR (1993). "Progress in chronic lymphocytic leukaemia: a historical perspective". Baillieres Clin Haematol. 6 (4): 757–65. PMID 8038488.
- ↑ World Health Organization Classification of Tumours of Haematopoietic and Lymphoid Tissues, Swerdlow SH, Campo E, Harris NL (Eds), IARC Press, Lyon 2008.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 Schwock J, Geddie WR (2012). "Diagnosis of B-cell non-hodgkin lymphomas with small-/intermediate-sized cells in cytopathology". Patholog Res Int. 2012: 164934. doi:10.1155/2012/164934. PMC 3368210. PMID 22693682.
- ↑ Review Article: Diagnostic Workup of Small B Cell Lymphomas: A Laboratory Perspective http://www.hindawi.com/journals/lymph/2012/346084/A Accessed on May 4, 2016
- ↑ Nabhan C, Rosen ST (2014). "Chronic lymphocytic leukemia: a clinical review". JAMA. 312 (21): 2265–76. doi:10.1001/jama.2014.14553. PMID 25461996.
- ↑ Chronic Lymphocytic Leukemia. Wikipedia (2015) https://en.wikipedia.org/wiki/B-cell_chronic_lymphocytic_leukemia Accessed on October,12 2015