Home About us Editorial board Ahead of print Current issue Search Archives Submit article Instructions Subscribe Contacts Login 


 
 Table of Contents  
CORRESPONDENCE
Year : 2013  |  Volume : 9  |  Issue : 1  |  Page : 148-150

Detection of atypical metastases in recurrent adenoid cystic carcinoma of parotid gland


Department of Nuclear Medicine & PETCT, Amrita Institute of Medical Sciences, Cochin, Kerala, India

Date of Web Publication10-Apr-2013

Correspondence Address:
Anshu Tewari
Department of Nuclear Medicine & PETCT, Amrita Institute of Medical Sciences, Cochin, Kerala
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0973-1482.110374

Rights and Permissions
 > Abstract 

We report a known case of adenoid cystic carcinoma of right parotid gland in a 36-year-old Indian male, diagnosed 5 years ago for which he underwent surgery followed by radiotherapy. Now the patient has presented to the surgical oncologist with a mass near angle of right jaw. Computed tomography (CT) performed elsewhere was reported negative for local recurrence. Subsequently, 18 F Fluorodeoxyglucose positron emission tomography-CT (FDG PET-CT) demonstrated local recurrence in right parotid bed. Surprisingly, metabolically active metastatic skeletal deposits were also identified, thus the disease was upstaged and management was changed. Trucut biopsy from left iliac bone lesion confirmed metastases from adenoid cystic carcinoma. Thus a whole body PET-CT has a significant impact on management of patients with salivary gland malignancies in assessing both local recurrence as well as distant metastases, especially in atypical and unsuspected sites.

Keywords: Adenoid cystic carcinoma, fluorodeoxyglucose, parotid gland, positron emission tomography, trucut biopsy


How to cite this article:
Tewari A, Padma S, Sundaram PS. Detection of atypical metastases in recurrent adenoid cystic carcinoma of parotid gland. J Can Res Ther 2013;9:148-50

How to cite this URL:
Tewari A, Padma S, Sundaram PS. Detection of atypical metastases in recurrent adenoid cystic carcinoma of parotid gland. J Can Res Ther [serial online] 2013 [cited 2019 Sep 19];9:148-50. Available from: http://www.cancerjournal.net/text.asp?2013/9/1/148/110374


 > Introduction Top


Tumors of salivary glands are rare and represent less than 1% of all cancers and approximately 5% of head and neck cancers. Parotid glands, being the largest salivary gland are also the most common site of salivary tumors, accounting for 75% of salivary gland malignancies. Among the salivary neoplasms, adenoid cystic carcinoma also known as cylindroma is very rare and constitutes 1% of major and minor salivary glands malignancies and accounts for only 15% of parotid malignancies. [1]


 > Case Report Top


We report a known case of adenoid cystic carcinoma of right parotid gland in a 36-year-old Indian male, diagnosed 5 years ago for which he underwent total parotidectomy followed by postoperative adjuvant radiotherapy (RT) elsewhere (60 Gy/30 fractions). Now patient has presented to the surgical oncologist with a mass near right angle of jaw. 18 F Fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) was performed on a PET 8 slice CT scanner to assess the present disease status. Eight millicurie of 18 F FDG was injected intravenously in euglycemic status and head to mid thigh imaging was performed an hour later. The whole body PET-CT scan revealed abnormal enhancing lesions with increased FDG uptake in right parotid bed, that is, posterior to mandibular condyle, anterior to external auditory canal and another lesion in digastric groove lying posterior to styloid process (standard uptake value (SUV) max is 5.7 g/ml) consistent with local tumor recurrence and associated infiltration of tumor into facial nerve [Figure 1]. Although clinically only a local recurrence was suspected, PET-CT revealed metabolically active skeletal metastases involving the spine of right scapula and left iliac bone (SUV max 4.1 and 2.6 g/ml, respectively) [Figure 2] and [Figure 3]. Thus PET-CT has upstaged the disease and changed the management. Trucut biopsy from left iliac bone lesion and fine needle aspiration cytology (FNAC) from right parotid bed confirmed the lesions to be metastases from adenoid cystic carcinoma and local recurrence [Figure 4]. Patient underwent completion parotidectomy along with right sural nerve graft and gold weight right upper eye lid repair for ptosis followed by a palliative RT to the scapula and iliac crest with 30-45 Gy in 15 fractions. Three months post therapy PET-CT scan showed partial metabolic response (reduction in SUV) of right parotid, left iliac, and right scapular lesions with no further progression of disease [Figure 5].
Figure 1: 18F FDG PET-CT fused transaxial image of neck: shows abnormal enhancing lesions with an increased FDG uptake in right parotid bed, that is, posterior to mandibular condyle, anterior to external auditory canal and another lesion in digastric groove that lies posterior to styloid process (standard uptake value (SUV) max is 5.7 g/ml) consistent with local tumor recurrence and associated infiltration of tumor into facial nerve.

Click here to view
Figure 2: 18F FDG PET-CT fused transaxial image shows metabolically active skeletal deposit in spine of right scapula (SUV Max 4.1)

Click here to view
Figure 3: FDG PET-CT fused transaxial image shows FDG avid left iliac bone skeletal deposits (SUV Max 2.6)

Click here to view
Figure 4: Histopathological section of local recurrence: High power (400 ×) view of H and E stained biopsy demonstrating cribriform pattern. Smears were cellular comprising of well delineated, tight cohesive clusters of baseloid cells, surrounding mucoid, hyaline globules or clear spaces also, forming honey comb (cribriform) pattern consistent with adenoid cystic carcinoma parotid gland

Click here to view
Figure 5: Comparison images (top row shows CT images, bottom row shows fused PET-CT images in transaxial view) of pre- and post therapy fused PET-CT showing partial metabolic resolution of right scapular deposit (previous SUV Max of 5.7 became 2.3 gm/ml now). Please note pre- and post radiotherapy CT images show persistence of lytic lesions in right scapula thus highlighting its insensitivity in reporting therapy response.

Click here to view



 > Discussion Top


Salivary gland tumors are usually benign and by far the most common site is the parotid. Of the parotid gland malignancies, mucoepidermoid carcinoma is the most frequent with an incidence of 21.8%. [1],[2] Other parotid malignancies that are known to occur are adenocarcinoma, squamous cell carcinoma, and adenoid cystic carcinoma in descending order of incidence. [2] 18 F-FDG PET has been shown to be superior to conventional imaging in evaluating patients with head and neck malignancies. [3] In major types of head and neck malignancies like squamous cell carcinoma and lymphomas, FDG PETCT is now used in initial staging, management of recurrent cancers, and therapeutic monitoring. [4] According to recent reports, [5] the higher sensitivity and diagnostic accuracy of PET-CT endows it with many advantages over CT alone in managing malignancies around the salivary gland, especially in high-grade types. Enhanced glucose metabolism, as determined by the SUV, is a strong index of tumor grade in several malignancies. [4] A correlation exists between 18 F-FDG uptake and tumor invasiveness. Tumour histologic grade is significantly related to FDG uptake. The tumour is aggressive if SUV is greater than 4.0. High-grade salivary malignancies tend to have higher 18 F-FDG uptake than low- or intermediate-grade salivary tumors. The preoperative diagnosis of salivary gland masses should include fine needle aspiration biopsy (FNAB), CT, or magnetic resonance imaging (MRI) as well as 18 F-FDG PET. In detecting metastatic neck disease, preoperative FDG PET is more sensitive than CT. Main limitation with FDG PET-CT is the fact that low-grade salivary gland malignancies with relatively low FDG uptake may be easily obscured by the normal physiologic FDG uptake of the salivary glands with reported SUV of less than 2.9 g/ml. [5] In addition, FDG uptake may be increased by inflammatory processes, contributing to false-positive results. [5] These errors can be corrected when conventional CT or MRI is combined with FDG PET.

The sensitivity and specificity of CT in detecting extracranial adenoid cystic carcinoma of oral cavity and oropharyngeal tumors with perineural spread are 88% and 89%, respectively. [8],[9] However, false negative results on CT are commonly associated with inherent insensitivity in identifying especially lymph nodal micro metastases (nodes less than 1 mm in size) and skeletal deposits [6],[8] suggesting that CT alone may be insufficient in staging, particularly in patients with high-grade salivary gland malignancies. [9]

Distant metastases from primary malignant parotid tumors are quite rare, [5] lungs being the most common followed by bone and liver. Although literature review reported metastases in context to adenoid cystic carcinoma, acinic cell carcinoma, [5] none of them reported scapular and ilium as site of distant metastases. Only one humeral metastases from parotid adenocarcinoma has been described in a canine. [7] Our case may be the first report of parotid adenoid cystic carcinoma presenting with scapular and iliac bone metastases. These tumors are slow growing with propensity to recur to adjacent structures easily. Recurrence and metastases usually happens years after initial presentation, therefore long-term follow up and constant vigilance is necessary . . On the contrary, this patient presented with local recurrence as well as skeletal metastases in a span of 5 years. FDG PECT-CT has a significant role in diagnosing such atypical and highly unsuspected site of distant metastases in the management of patients with adenoid cystic carcinoma of parotid gland.

 
 > References Top

1.Spiro RH. Salivary neoplasms: Overview of a 35-year experience with 2,807 patients. Head Neck Surg 1986;8:177-84.  Back to cited text no. 1
    
2.Buchner A, Merrell PW, Carpenter WM. Relative frequency of intraoral minor salivary gland tumors: A study of 380 cases from northern California and comparison to reports from other parts of the world. J Oral Pathol Med 2007;36:207-14.  Back to cited text no. 2
    
3.Kresnik E, Mikosch P, Gallowitsch HJ, Kogler D, Wiesser S, Heinisch M, et al. Evaluation of head and neck cancer with 18 F-FDG PET: A comparison with conventional methods. Eur J Nucl Med 2001;28:816-21.  Back to cited text no. 3
    
4.Jeong HS, Chung MK, Son YI, Choi JY, Kim HJ, Ko YH, et al. Role of 18 F-FDG PET/CT in management of high-grade salivary gland malignancies. J Nucl Med 2007;48:1237-44.  Back to cited text no. 4
    
5.Lima RA, Tavares MR, Dias FL, Kligerman J, Nascimento MF, Barbosa MM, et al. Clinical prognostic factors in malignant parotid gland tumors. Otolaryngol Head Neck Surg 2005;133:702-8.  Back to cited text no. 5
    
6.Mukherji SK, Weeks SM, Castillo M, Yankaskas BC, Krishnan LA, Schiro S. Squamous cell carcinomas that arise in the oral cavity and tongue base: Can CT help predict perineural or vascular invasion? Radiology 1996;198:157-62.  Back to cited text no. 6
    
7.Habin DJ,Else RW. Parotid salivary gland adenocarcinoma with bilateral ocular and osseous metastases in a dog, J Small Anim Pract 1995;36:445-9.  Back to cited text no. 7
    
8.Nakamoto Y, Tatsumi M, Hammoud D, Cohade C, Osman MM, Wahl RL. Normal FDG distribution patterns in the head and neck: PET/CT evaluation. Radiology 2005;234:879-85.  Back to cited text no. 8
    
9.Hanna E, Vural E, Prokopakis E, Carrau R, Snyderman C, Weissman J. The sensitivity and specificity of high-resolution imaging in evaluating perineural spread of adenoid cystic carcinoma to the skull base. Arch Otolaryngol Head Neck Surg 2007;133:541-5.  Back to cited text no. 9
    


    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]



 

Top
 
 
  Search
 
Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

  >Abstract>Introduction>Case Report>Discussion>Article Figures
  In this article
>References

 Article Access Statistics
    Viewed3817    
    Printed76    
    Emailed0    
    PDF Downloaded195    
    Comments [Add]    

Recommend this journal


[TAG2]
[TAG3]
[TAG4]