Acinic cell carcinoma differential diagnosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Ramyar Ghandriz MD[2]

Overview

Acinic cell carcinoma is a head and neck tumor happening in the salivary glands. If a patient was observed with related signs, the tumor must be classified as a benign or invasive by the capsule being intact. Differential diagnosis of a malignant tumor in the salivary gland is made after the incision and by histology features which will provide a good chemotherapy regimen for so-called patients.

Differentiating acinic cell carcinoma from other Diseases

• Based on tumor site differentiation is as below:

Diseases	Benign/ Malignant	Clinical manifestation						Paraclinical findings			Gold standard diagnosis
		Demography	History	Symptoms		Signs		Lab findings	Histopathology	Imaging
				Pain	Dysphagia	Mass exam	Others
Pleomorphic adenoma	Benign	More common in females Incidence increase with age Incidence: 2-3.5 cases per 100,000 population	History of swelling Dysphagia Hoarseness	−	+	Palpable mass of deep lobe of parotid gland Firm Mobile	−	−	Proliferation of epithelial cells and stromal matrix in the ducts	MRI: Homogenous on T1 Abundant myxochondroid stroma on T2	Biopsy
Warthin's tumor	Benign	Male to female ratio: 4:1 More common in people aged 60-70 years old	History of swollen salivary gland Jaw pain Tinnitus	−	+	Non tender Mobile Firm Solitary	−	−	Papillae Fibrous capsule Cystic spaces	Neck CT: Cystic lesion posteriorly within the parotid gland MRI: B/L heterogeneous lesions	Biopsy
Oncocytoma	Benign	Race: Caucasian patients predilection Gender: No gender preference Age: 50–70 years	Growing palpable painless mass Facial swelling Lymphadenopathy (if transformed to malignant)	±	±	Firm, multilobulated Mobile mass	Normal Redness Swelling Skin ulceration	Normal Anemia	Epithelial cells with eosinophilic Granular cytoplasm Rich in mitochondria	CT: Isodense expansive mass Enhancement after intravenous contrast Hypodense areas MRI: Isodensties on T1 Mass is hyperintense on T2 Enhancement on contrast	Incisional biopsy and histopathological examination
Monomorphic adenoma	Benign or malignant	Age: 26-76 years Rare in children Gender: No predilection	Growing palpable painless mass on jaw or in oral cavity Facial swelling Lymphadenopathy (if transformed to malignant) Pain and ulceration (in later stage)	±	±	Nodular Fluctuant swelling	Normal Redness Skin ulceration May have lymphadenopathy	Normal	Straw colored fluid on aspiration	Ultrasound: Used to biopsy the lesion May show cystic an solid components CT: useful for lesions with calcification and venous phleboliths MRI: Test of choice Differentiate benign from malignant Defines tumor extent Shows perineural spread	Incisional biopsy and histopathological examination
Mucoepidermoid carcinoma	Malignant	Age: Mean age of 59 Female predilection	Painlesss mass Swelling in oral cavity Lymphadenopathy	±	±	Cystic and solid mass	May have lymphadenopathy	−	Gross findings: Firm Tan-white to yellow Bosselated Cystic Microscopic findings: Encapsulated squamous and glandular components	Cystic and solid component with variable appearance on CT and MRI	Incisional biopsy and histopathological examination
Adenoid cystic carcinoma	Malignant	Age: 40s-60s Gender: Female predominance	Slow growing rare tumor with low recurrence	±	±	Solid mass	Normal to ulcerated lesions May have lymphadenopathy	−	Gross findings: Tubular Cribriform Solid pattern of growth Microscopic findings: Components of large cells with pleomorphic nuclei Increased mitotic activity Focal necrosis	Imaging reveal dimensions of the tumor, local spread, and distant metastasis	Biopsy and histopathological examination
Adenocarcinoma	Malignant	Age: young age predilection	Its a tumor of minor salivary glands May present as small ulceration or nodules in oral cavity	−	−	Small nodules in oral cavity With or without lymphadenopathy	Normal to ulcerated lesions May have lymphadenopathy	May be normal Or may show anemia and blood cell disorders with distant bone invasion	On histology it is confused with Adeocyctic carcinoma Components of gland and cyst formations More perineural invasion	CT and MRI MRI being more accurate for adjacent tissue involvement and lymphadenopathy	Biopsy and histopathological examination
Salivary duct cancer	Malignant (Highly aggressive)	Incidence: 1-3% Gender: Male predilection Mean age: 55-61 years old	Rapidly growing mass with jaw involvement	±	±	Painless Hard Non-compressible mass	Ulceration of mucosa and skin May have lymphadenopathy facial paralysis in case of facial nerve involvement	Pathomorphologically tumor of salivary ducts resembles tumor of breast ducts	Gross findings: Firm mass Cystic component of variable size and dimension Microscopic finding: Resembling ductal carcinoma of breast Intraductal components invading surrounding tissue in several forms: cribriform papillary Solid with comedo-like central necrosis	Non-specific features on CT and MRI Shows neural and jaw involvement	Biopsy and histopathological examination
Squamous cell carcinoma	Malignant	Incidence: rare Age: Old age , 61-68 years Male predilection	Present as painful growing mass on jaw	+	−	Teneder Firm Solitary swelling on jaw	Submandibular gland predilection Thinning and discoloration of skin	Past radiation exposure is a strong risk factor	Gross findings: Thinning of skin Microscopically findings: Nest and solid sheets of tumor cells arranged in glandular pattern Immunohistochemical staining can be used to mark the squamous and keratin component	Tumor dimension can be delineated using both CT and MRI	Biopsy and histopathological examination

Differentiating acinic cell carcinoma from other diseases on the basis of histology findings

On the basis of histologist findings acinic cell carcinoma must be differentiated from other salivary and head and neck masses such as salivary metastasis of thyroid carcinoma, salivary oncocytoma, mucoepidermoid carcinoma, Mammary analog secretory carcinoma.

Diseases	Histological findings
	Overlapping features	Distinguishing features
Salivary metastasis of thyroid carcinoma	Empty appearance, grooves, pseudoinclusions	Immunohistochemistry (Thyroglobulin)
salivary oncocytoma	Eosinophilic, non-serous cells	Hematoxylin
mucoepidermoid carcinoma	Microcystic, and follicula, inconspicuous mucous/squamoid cells, eosinophilic	Immunohistochemistry for p63
Mammary analoge secretory carcinoma	Histologically similar	Lack of PAS-positive secretory granules, Vimentin positive, Adipophilin positive