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autofluorescence imaging: a case report. Head & Neck Oncology 2009;1:37

原文作者姓名: Nadarajah Vigneswaran, Sheila Koh, Ann Gillenwater 通訊作者學校: The University of Texas Dental Branch at Houston, Houston,

Texas 77030, USA 報告者姓名(組別): 張嘉倫 Intern B 組

報告日期: 99/09/07

內文:

Abstract

a. Background:

1. Autofluorescence is used for diagnostic evaluation of various epithelial malignancies.

2. Cancerous lesions display loss of autofluorescence due to malignant changes in epithelium and subepithelial stroma.

3. We use of autofluorescence imaging for detecting a clinically innocuous appearing occult malignancy of the palate which upon pathological

examination was consistent with a metastatic squamous cell carcinoma.

b. Case Description:

1. A submucosal nodule was noted on the right posterior hard palate of a 59 year-old white female during clinical examination.

2. Four years ago, this patient was diagnosed with metastatic squamous cell carcinoma of the right mid-jugular lymph node of unknown primary.

3. She was treated with external beam irradiation and remained disease free until current presentation.

4. Examination of this lesion using autofluorescence at 405 nm illumination and excisional biopsy.

c. Conclusion:

This case illustrates the important role played by autofluorescence tissue imaging in diagnosing a metastatic palatal tumour that appeared clinically innocuous and otherwise would not have been biopsied.

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1. Light-induced tissue autofluorescence examination is currently considered as a standard of care for screening and diagnostic evaluation of early neoplastic changes of the skin, cervix, lung, bladder, gastrointestinal tract and oral cavity .

2. Dysplastic and cancerous tissues often exhibit decreased blue-green autofluorescence and appear darker compared to uninvolved mucosa.

3. Most of this reduction in perceived fluorescence is attributed to diminished signal (detectable from the surface) that emanates from collagen crosslink within the subepithelial stroma.

4. Recently the U.S. Food and Drug Administration has approved

autofluorescence-based oral mucosal screening devises which are marketed as VELscope and Identafi™ 3000 for early detection of potentially malignant oral lesions.

5. Here we report of a case to highlight the value of tissue autofluorescence visualization in diagnosing a squamous cell carcinoma, metastatic to the palate, which clinically presented as an innocuous appearing submucosal nodule.

Case Report

1.Oral examination:

A 59-year-old white female noticed a submucosal nodule on her posterior hard palate during routine oral examination.

2.Personal habits:

The patient had a 10-pack-year history of smoking and social consumption of alcohol. The patient's family history was unremarkable.

3.Lesion size:

The patient was unaware of this lesion. This lesion was covered by intact mucosa, was non-fluctuant and had the consistency of an irritation fibroma. This submucosal nodule measured 0.8 cm in greatest diameter and palpation of this nodule elicited no tenderness or blanching.

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Her medical history is significant for cervical lymph node metastasis of squamous cell carcinoma from unknown primary, hypertension, chronic obstructive

pulmonary disease, hypothyroidism and depression.

5.Diagnosis

The patient was diagnosed with squamous cell carcinoma of unknown

primary, metastatic to the right mid jugular lymph nodes approximately four years ago. Various imaging studies were performed at the time which failed to identify the primary site of this tumour.

6.Treatment

The patient was treated with a course of external beam radiation therapy to the pharyngeal axis and the neck. Her oral mucosa and teeth were shielded from the direct radiation therapy beams.

7.Medications

Her current medications include levothyroxine, enalapril malate and fluoxetine.

levothyroxine enalapril malate fluoxetine

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8.Differential diagnosis:

Our clinical differential diagnosis for this palatal nodule included traumatic fibroma and epidermoid cyst.

9.Method:

However, because of her past medical history of metastatic disease, we examined this nodule using a multispectral oral cancer screening device (Identafi™ 3000).

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Patient was referred for further evaluation and treatment.

Discussion

1.Increasing need for additional non-invasive tests

→light-induced fluorescence visualization devices

→for detection and delineation of potentially malignant oral lesions

→The U.S. Food and Drug administration has approved two oral cancer screening devices namely, VELscope® and Identafi 3000™

2.light-induced fluorescence visualization of oral mucosa

VELscope

→uses a blue/violet light (400-460 nm)

→illuminate oral mucosa and a specific filter allows the clinician to visualize tissue autofluorescence.

Identafi 3000

→white, amber (560 nm) to visualize the oral mucosal reflectance

→violet (405 nm) to visualize fluorescence.

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→used increasingly as non-invasive diagnostic

→biochemical and structural changes associated with neoplastic transformation

4.The type of fluorophores being visualized:

→1) endogenous fluorophores (autofluorescence)

→2) fluorophores synthesized in tissue after administration of a precursor drug

→3) fluorophores injected as exogenous drug

5.The major fluorophores of oral mucosa

→flavin adenine dinucleotide (FAD)

→nicotinamide adenine dinucleotide (NADH)

Subepithelial stromal collagen fibers are the predominant source of autofluorescence in oral mucosa

6.Normal mucosa V.S Specific components of mucosa

violet (405 nm Identafi™ 3000 system) blue light (436 nm VELscope system)

→normal mucosa is illuminated by high-intensity

→specific components of mucosa (fluorophores) emit low-energy light

***Reason:

malignant transformation

→ thickening of the epithelium

→ increased nuclear cytoplasmic ratio

→ enhanced cellular density

→ decrease in collagen autofluorescence 7.Recent studies

[a.]Roblyer et al. examined light-induced tissue autofluorescence at multiple excitation wave lengths at 365, 380, 405 and 450 nm could differentiate the

dysplastic epithelia and carcinoma from histologically normal mucosa with 95.9%

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[b.]Subclinical premalignant and malignant lesions that are not visible on routine white light oral examination become noticeable with direct autofluorescence visualization

[c.]Recent studies reported that autofluorescence tissue imaging is more sensitive than routine white light examination to determine surgical margins at the primary site that are free of histologic and molecular features of malignancy or dysplasia

8.Carcinoma of unknown primary site (CUP)

defined as metastatic carcinoma present in the lymph nodes with no identifiable primary tumour despite thorough clinical and radiographic evaluations.

The incidence of CUP, which represents up to 7% of all head and neck carcinomas, has reduced in recent years due to the use of multimodal imaging studies to identify occult primary tumours.

Approximately 75% of CUP occurring in the cervical lymph nodes in which the primary tumours were subsequently identified originated from the head and neck area,most frequently from the peritonsillar area and base of the tongue.

9.Our case

The patient in our case had no clinical evidence of primary tumour or recurrence for 4 years until she presented with the described palatal tumour. We believe that this tumour represents a second metastasis and not a primary tumour

because the surface epithelium overlying this submucosal tumour was not directly connected to the tumour island and did not exhibit histologic features of dysplasia or malignancy as noted with primary oral squamous cell carcinomas.

10.Conclusion

multispectral tissue autofluorescence is a new and powerful technology that can be used for multiple diagnostic applications.

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題號 題目

1 Which is not symptom of epithelial dysplasia ? (A) Abnormal mitosis

(B) Pleomorphism (C) Keratin pearl (D) Hyperkeratosis 答案

(D)

出處:Oral and Maxillofacial Pathology,Neville 2nd p.343

題號 題目

2 Which item about Squamous cell carcinoma is right?

(A) Associate with smoking (B) Most metastasis of breast (C) Most predilection of female (D) Decrease with age

答案 (A)

出處:Oral and Maxillofacial Pathology,Neville 2nd p.321

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