Microscopic view of salivary gland cells with a hidden cancerous element.

Rare Salivary Gland Tumors: When Cytology Uncovers the Unexpected

Mira Elwood in Health & Wellness December 2025 • 4 min read.

"Exploring the Unusual: How Cytological Analysis Aids in Diagnosing Acinic Cell Carcinoma"

Acinic Cell Carcinoma (AcCC) is a slow-growing malignant tumor primarily found in the parotid gland, a major salivary gland. It is rare to find it in the submandibular gland, minor salivary glands, or in heterotopic salivary gland tissue (HSGT) – salivary gland tissue in an abnormal location. The challenge? These unusual locations and presentations can easily lead to delayed or incorrect diagnoses.

Fine Needle Aspiration Cytology (FNAC) is a vital tool for diagnosing AcCC before surgery. However, diagnosing AcCC through cytology can be tricky, and misdiagnosis can impact long-term prognosis. This article explores two unusual cases of AcCC, highlighting the importance of cytological features in preoperative diagnosis.

We will delve into a case of AcCC developing in HSGT and another presenting as a synchronous bilateral tumor, emphasizing how clinical suspicion combined with cytological analysis are key to accurate diagnosis. Discover how a skilled cytopathologist plays a crucial role in preliminary diagnosis, ensuring timely and appropriate treatment.

Unveiling Acinic Cell Carcinoma: Diagnostic Clues and Cytological Insights

Microscopic view of salivary gland cells with a hidden cancerous element.

ACCC is an uncommon salivary gland tumor, generally encapsulated and less than 3 cm in size. It is more common among males in their third decade of life and has a rare familial prevalence. Alterations in chromosomes, such as 6q rearrangement, loss of the Y chromosome, and gain of chromosomes 7 and 8, are related to the occurrence of familial AcCC. Another factor is radiation exposure.

Cytological diagnosis can be tricky due to a low yield of cells in papillary-cystic variants, or similarities to benign salivary gland tissue or tumors with oncocytic or clear cell components. Histologically, ACCC presents in solid, microcystic, follicular, and papillary-cystic patterns. The tumor cells typically feature basophilic granular cytoplasm and monotonous, bland nuclei, and rare mitotic figures. Other rare cell types include intercalated duct cells, clear cells, vacuolated cells, and non-specific glandular cells.

Microacinar Groupings: Presence of cells in microacinar groupings within the smear.
Cellular Features: Cells display abundant, finely vacuolated cytoplasm.
Nuclear Characteristics: Minimal anisokaryosis and bland nuclear chromatin observed.
Background Elements: Presence of many stripped nuclei.

A prolonged follow-up is essential for ACCC patients, with focus on the contralateral gland. Clinical and radiological examinations help detect synchronous contralateral tumors, crucial for management and prognosis. Synchronous contralateral tumors were detected in the second case, representing a unique presentation that could easily be missed without clinical suspicion.

The Critical Role of Early Detection

ACCC, while rare and slow-growing, demands careful attention due to its potential for misdiagnosis. It can develop in unusual locations such as the submandibular or minor salivary glands or, extremely rarely, in HSGT.

FNAC plays a vital role in diagnosing ACCC, and cytopathologists are critical to its preliminary diagnosis. It's easily missed clinically, radiologically, and cytologically.

Through increased awareness and vigilance, healthcare professionals can improve early detection rates, ultimately leading to more effective treatment and better outcomes for individuals affected by this rare salivary gland tumor.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.7860/jcdr/2016/19753.8374, Alternate LINK

Title: Two Unusual Cases Of Acinic Cell Carcinoma: Role Of Cytology With Histological Corelation

Subject: Clinical Biochemistry

Journal: JOURNAL OF CLINICAL AND DIAGNOSTIC RESEARCH

Publisher: JCDR Research and Publications

Authors: Rumpa Das

Published: 2016-01-01

Everything You Need To Know

Where does Acinic Cell Carcinoma typically occur, and what makes it difficult to diagnose?

Acinic Cell Carcinoma (AcCC) typically appears as a slow-growing malignant tumor, predominantly in the parotid gland. Its occurrence is rare in the submandibular gland, minor salivary glands, or in heterotopic salivary gland tissue (HSGT). The challenge in diagnosing Acinic Cell Carcinoma lies in its unusual locations and presentations, which can lead to misdiagnosis. The tumor cells feature basophilic granular cytoplasm and monotonous, bland nuclei, and rare mitotic figures.

How does Fine Needle Aspiration Cytology (FNAC) aid in the diagnosis of Acinic Cell Carcinoma, and what cytological features are looked for?

Fine Needle Aspiration Cytology (FNAC) is essential for diagnosing Acinic Cell Carcinoma before surgical intervention. Diagnosing Acinic Cell Carcinoma through cytology can be complex, and misdiagnosis can affect long-term prognosis. Key cytological features used in preliminary diagnosis include microacinar groupings, cells with abundant vacuolated cytoplasm, bland nuclear chromatin, and the presence of many stripped nuclei.

Why is prolonged follow-up important for patients diagnosed with Acinic Cell Carcinoma, and what specific monitoring is recommended?

While Acinic Cell Carcinoma is generally a slow-growing tumor, prolonged follow-up is essential, focusing on the contralateral gland. Clinical and radiological examinations are important to detect synchronous contralateral tumors, which are crucial for management and prognosis. The detection of synchronous contralateral tumors, as seen in the second case, highlights a unique presentation that could be missed without clinical suspicion.

Are there any genetic or environmental factors associated with Acinic Cell Carcinoma?

Certain chromosomal alterations have been associated with familial Acinic Cell Carcinoma, including 6q rearrangement, loss of the Y chromosome, and gain of chromosomes 7 and 8. Other factors, such as radiation exposure, may also contribute to the occurrence of Acinic Cell Carcinoma. Further research is needed to fully understand the genetic and environmental factors influencing Acinic Cell Carcinoma development.

What factors can lead to a misdiagnosis of Acinic Cell Carcinoma, and why is a skilled cytopathologist so important in this process?

Misdiagnosing Acinic Cell Carcinoma can stem from similarities to benign salivary gland tissue or other tumors with oncocytic or clear cell components. The low yield of cells in papillary-cystic variants further complicates cytological diagnosis. A skilled cytopathologist plays a crucial role in distinguishing Acinic Cell Carcinoma from other salivary gland lesions, ensuring timely and appropriate treatment decisions are made. Recognizing these subtle differences is vital for preventing delayed or incorrect diagnoses and optimizing patient outcomes.