Dysplasia with lymphocytic band – the so-called “lichenoid dysplasia�
The term “lichenoid†is used by many [i]pathologists[/i] to denote a lymphocytic band, sparse or dense, that hugs the epithelial-connective tissue interface. This term is also used by [i]clinicians[/i] to mean a red and white area, that may or may not be reticulated. If you add the fact that oral lichen planus is considered by some to be premalignant, and the scene is set for confusion.
[u]Clinical and Histopathologic Findings [/u]
Here is an example of how things get confused. Let’s say the patient is a 60 year old woman with a 1 ppd cigarette smoking habit x 10 years, who quit 30 years ago, and now presents with a unilateral, red area with some white papules, on the left ventral tongue that is slightly sensitive, measuring 1.5-2.0 cm. There are no reticulations.
Scenario 1: Clinician #1 sees the red and white lesion, makes a clinical diagnosis of lichen planus (in spite of the fact that the lesion is unilateral and not reticulated), takes a biopsy, and writes “lichen planus†on the requisition form. Pathologist #1 sees some mild-to-moderate dysplasia and makes a diagnosis of “lichenoid dysplasiaâ€. Clinician #1 sees the report which reinforces in his/her mind the [u]controversial[/u] notion that lichen planus is a “potentially malignant†condition and sends the patient for further management (hopefully). Will this lead the clinician to biopsy every case of lichen planus, even for lesions that are clearly reticulated, and bilaterally symmetric?
Scenario 2: Clinician #2 sees the same lesion, makes a clinical diagnosis of erythro-leukoplakia, takes a biopsy and writes “erythro-leukoplakia, r/o dysplasia or carcinoma†on the requisition form. Pathologist #2 sees the same findings and makes a diagnosis of “mild-to-moderate dysplasia, extending to the tissue edges, with a second diagnosis of parakeratosis and chronic inflammationâ€. Clinician #2 sees this report which reinforces in his/her mind the [u]universally accepted[/u] concept that erythro-leukoplakias have a high frequency of being dysplastic or cancerous and sends the patient for further management. The question of lichen planus never comes up. This clinician does not routinely biopsy lichen planus that presents as reticulated white areas with some interspersed red or ulcerated areas, that present symmetrically on the buccal mucosa, ventral tongue, and posterior gingiva. He/she only biopsies unilateral lesions because he/she is concerned that they may actually represent erythro-leukoplakia.
That lymphocytic band is very commonly seen beneath dysplasias and a careful evaluation of areas beyond the area of dysplasia will show that there is minimal-to-no lymphocytic infiltration at the edges that are not dysplastic. This same band is very commonly seen beneath infiltrating squamous cell carcinomas and is likely a T-cell response to altered antigens on dysplastic/cancerous keratinocytes.
As such, pathologists should avoid using the term “lichenoid dysplasia†as a diagnosis for oral dysplasias. Rather, stick with “[grade] dysplasia [involvement of margins] to reduce confusion.
There is no question that there are cases of oral lichen planus that become associated with squamous cell carcinoma. There is increasing evidence that long-term chronic inflammation and mucosal injury may lead to malignant transformation in some cases. However, whether other factors play a role has not been clearly documented such as iatrogenic or other immunosuppression, past history of cancer or family history of cancer. One researcher has called oral cancer “wound healing gone awryâ€; after all, the same mechanisms control cell proliferation in wound healing and cancer. It is a question of how that control is lost.
[u]Clinical and Histopathologic Findings [/u]
Here is an example of how things get confused. Let’s say the patient is a 60 year old woman with a 1 ppd cigarette smoking habit x 10 years, who quit 30 years ago, and now presents with a unilateral, red area with some white papules, on the left ventral tongue that is slightly sensitive, measuring 1.5-2.0 cm. There are no reticulations.
Scenario 1: Clinician #1 sees the red and white lesion, makes a clinical diagnosis of lichen planus (in spite of the fact that the lesion is unilateral and not reticulated), takes a biopsy, and writes “lichen planus†on the requisition form. Pathologist #1 sees some mild-to-moderate dysplasia and makes a diagnosis of “lichenoid dysplasiaâ€. Clinician #1 sees the report which reinforces in his/her mind the [u]controversial[/u] notion that lichen planus is a “potentially malignant†condition and sends the patient for further management (hopefully). Will this lead the clinician to biopsy every case of lichen planus, even for lesions that are clearly reticulated, and bilaterally symmetric?
Scenario 2: Clinician #2 sees the same lesion, makes a clinical diagnosis of erythro-leukoplakia, takes a biopsy and writes “erythro-leukoplakia, r/o dysplasia or carcinoma†on the requisition form. Pathologist #2 sees the same findings and makes a diagnosis of “mild-to-moderate dysplasia, extending to the tissue edges, with a second diagnosis of parakeratosis and chronic inflammationâ€. Clinician #2 sees this report which reinforces in his/her mind the [u]universally accepted[/u] concept that erythro-leukoplakias have a high frequency of being dysplastic or cancerous and sends the patient for further management. The question of lichen planus never comes up. This clinician does not routinely biopsy lichen planus that presents as reticulated white areas with some interspersed red or ulcerated areas, that present symmetrically on the buccal mucosa, ventral tongue, and posterior gingiva. He/she only biopsies unilateral lesions because he/she is concerned that they may actually represent erythro-leukoplakia.
That lymphocytic band is very commonly seen beneath dysplasias and a careful evaluation of areas beyond the area of dysplasia will show that there is minimal-to-no lymphocytic infiltration at the edges that are not dysplastic. This same band is very commonly seen beneath infiltrating squamous cell carcinomas and is likely a T-cell response to altered antigens on dysplastic/cancerous keratinocytes.
As such, pathologists should avoid using the term “lichenoid dysplasia†as a diagnosis for oral dysplasias. Rather, stick with “[grade] dysplasia [involvement of margins] to reduce confusion.
There is no question that there are cases of oral lichen planus that become associated with squamous cell carcinoma. There is increasing evidence that long-term chronic inflammation and mucosal injury may lead to malignant transformation in some cases. However, whether other factors play a role has not been clearly documented such as iatrogenic or other immunosuppression, past history of cancer or family history of cancer. One researcher has called oral cancer “wound healing gone awryâ€; after all, the same mechanisms control cell proliferation in wound healing and cancer. It is a question of how that control is lost.
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