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| MeshID = D017728 | | | MeshID = D017728 | |
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| {{SI}} | | {{Anaplastic large cell lymphoma}} |
| {{CMG}} | | {{CMG}} |
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| | ==[[Thyroid cancer overview|Overview]]== |
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| | ==[[Thyroid cancer historical perspective|Historical Perspective]]== |
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| ==Overview== | | ==[[Thyroid cancer classification|Classification]]== |
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| '''Anaplastic large cell lymphoma''' (ALCL) is a type of [[non-Hodgkin lymphoma]] that features in the World Health Organisation ([[WHO]]) classification of [[lymphoma]]s.
| | ==[[Thyroid cancer pathophysiology|Pathophysiology]]== |
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| ===Diagnosis=== | | ==[[Thyroid cancer causes|Causes]]== |
| To make this diagnosis under its present system of classification, the WHO:
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| Requires
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| *The presence of "hallmark" cells
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| *Immunopositivity for [[CD30]]
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| Acknowledges as typical, but does not require
| | ==[[Thyroid cancer epidemiology and demographics|Epidemiology and Demographics]]== |
| *Immunopositivity for ALK (anaplastic lymphoma kinase) protein
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| Specifically excludes
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| *Primary cutaneous [[T-cell]] lymphomas
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| *Other specific types of anaplastic lymphoma (particularly those of [[B-cell]] lineage) with CD30 positivity
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| The hallmark cells are of medium size and feature abundant [[cytoplasm]] (which may be clear, amphophilic or eosinophilic), kidney shaped [[cell nucleus|nuclei]], and a paranuclear eosinophilic region. Occasional cells may be identified in which the plane of section passes through the nucleus in such a way that it appears to enclose a region of cytoplasm within a ring; such cells are called "doughnut" cells.
| | ==[[Thyroid cancer screening|Screening]]== |
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| By definition, on histological examination, hallmark cells are always present. Where they are not present in large numbers, they are usually located around blood vessels. Morphologic variants include the following types:
| | ==[[Thyroid cancer natural history|Natural History, Complications and Prognosis]]== |
| *Common (featuring a predominance of hallmark cells)
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| *Small cell (featuring smaller cells with the same immunophenotype as the hallmark cells)
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| *Lymphohistiocytic
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| *Sarcomatoid
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| *Signet ring
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| ===Clinical features=== | | ==Diagnosis== |
| The lymphoma is more common in the young and in males. It occurs in both nodal and extranodal locations. It typically presents at a late stage and is often associated with systemic symptoms ("B symptoms"). During treatment, relapses may occur but these typically remain sensitive to [[chemotherapy]].
| | [[Thyroid cancer staging|Staging]] | [[Thyroid cancer history and symptoms|History and Symptoms]] | [[Thyroid cancer physical examination|Physical Examination]] | [[Thyroid cancer laboratory findings|Laboratory Findings]] | [[Thyroid cancer chest x ray|Chest X Ray]] | [[Thyroid cancer CT|CT]] | [[Thyroid cancer MRI|MRI]] | [[Thyroid cancer echocardiography or ultrasound|Echocardiography or Ultrasound]] | [[Thyroid cancer other imaging findings|Other Imaging Findings]] | [[Thyroid cancer other diagnostic studies|Other Diagnostic Studies]] |
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| ===Immunophenotype=== | | ==Treatment== |
| The hallmark cells (and variants) show immunopositivity for CD30 (also known as Ki-1). True positivity requires localisation of signal to the cell membrane and/or paranuclear region (cyptolasmic positivity is considered non-specific and non-informative). Another useful marker which helps to differentiate this lesion from Hodgkin lymphoma is Clusterin. The neoplastic cells have a golgi staining pattern (hence paranuclear staining), which is characteristic of this lymphoma. The cells are also typically positive for a subset of markers of T-cell lineage. However, as with other T-cell lymphomas, they are usually negative for the pan T-cell marker CD3. Occasional examples are of null (neither T nor B) cell type. These lymphomas show immunopositivity for ALK protein in 70% of cases. They are also typically positive for EMA. In contrast to many B-cell anaplastic CD30 positive lymphomas, they are negative for markers of [[Epstein-Barr Virus]] (EBV).
| | [[Thyroid cancer medical therapy|Medical Therapy]] | [[Thyroid cancer surgery|Surgery]] | [[Thyroid cancer primary prevention|Primary Prevention]] | [[Thyroid cancer cost-effectiveness of therapy|Cost-Effectiveness of Therapy]] | [[Thyroid cancer future or investigational therapies|Future or Investigational Therapies]] |
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| === Molecular biology === | | ==Case Studies== |
| The majority of cases, greater than 90%, contain a clonal rearrangement of the T-cell receptor. This may be identified using PCR techniques, such as T-gamma multiplex PCR. Oncogenetic potential is conferred by upregulation of a [[tyrosine kinase]] gene on [[chromosome]] 2. Several different translocations involving this gene have been identified in different cases of this lymphoma. The most common is a [[chromosomal translocation]] involving the nucleophosmin gene on chromosome 5. The translocation may be identified by analysis of giemsa-banded metaphase spreads of tumour cells and is characterised by t(2;5)(p23;q35). The product of this [[Gene fusion|fusion]] [[gene]] may be identified by [[immunohistochemistry]] using antiserum to ALK protein. Probes are available to identify the translocation by fluorescent in situ hybridization. The nucleophosmin component associated with the commonest translocation results in nuclear positivity as well as cytoplasmic positivity. Positivity with the other translocations may be confined to the cytoplasm.
| | [[Thyroid cancer case study one|Case #1]] |
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| === Differential diagnosis and diagnostic pitfalls ===
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| As the appearance of the hallmark cells, pattern of growth (nesting within lymph nodes) and positivity for EMA may mimic [[metastatic]] [[carcinoma]], it is important to include markers for [[cytokeratin]] in any diagnostic panel (these will be negative in the case of anaplastic lymphoma). Other mimics include CD30 positive B-cell lymphomas with anaplastic cells (including Hodgkin lymphomas). These are identified by their positivity for markers of B-cell lineage and frequent presence of markers of EBV. Primary cutaneous T-cell lymphomas may also be positive for CD30; these are excluded by their anatomic distribution. ALK positivity may also be seen in some large cell B-cell lymphomas and occasionally in [[rhabdomyosarcoma]]s.
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| ===Prognostic factors===
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| Those with ALK positivity have a better [[prognosis]]. It is possible that ALK-negative anaplastic large cell lymphomas represent other T-cell lymphomas that are morphologic mimics of ALCL in a final common pathway of disease progression. It is possible that existing systems of classification will be revised in the future to exclude such lymphomas from this specific diagnosis.
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| === Treatment Overview ===
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| * Managed under "Aggressive Lymphoma" guidelines
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| ** [[CHOP]] is first line of treatment, CHOP-[[Rituxan]] in the unlikely scenario that [[CD20]] is positive, given that CD20 is a [[B-cell]] marker.
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| ** [[Radiation therapy]] as per institutional preference (based on ECOG, SWOG, and GELA trials), but usually added for bulky disease
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| * Overall better prognosis than other "Aggressive Lymphomas"
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| ** ALK+ 5-year survival 70-80%
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| ** ALK- 5-year survival 30-40%
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| ==External links==
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| * [http://www.lymphomainfo.net/nhl/types/alcl.html Lymphoma Information Network]
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| {{Hematological malignancy histology}} | | {{Hematological malignancy histology}} |