Adenoid Cystic Carcinoma (ACC)

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Summary

Adenoid cystic carcinoma (ACC) is a rare type of cancer that typically develops in the salivary glands of the head and neck. It belongs to a category of cancers called adenocarcinomas, where cancer cells grow in the epithelial tissue. The unique characteristic of ACC is its slow and gradual growth, making it a dangerous form of cancer.

This type of cancer tends to spread through the blood or along nerves to other parts of the body, a process known as perineural invasion. Because ACC is quite aggressive, treating and curing it can be challenging. The outcomes of both diagnosis and treatment are unpredictable, adding to the complexity of managing this particular cancer. The key is to approach it with a comprehensive and watchful strategy due to its slow but persistent nature.

What is Adenoid cystic carcinoma (ACC)

Adenoid cystic carcinoma (ACC) arises from the transformation of normal cells, leading to uncontrolled growth and the formation of a tumor mass in a specific part of the body. This type of cancer can be either malignant or benign, depending on the extent of its spread throughout the body. In the case of ACC, it develops in the salivary glands located in the neck and head region.

As a rare form of adenocarcinoma, ACC involves the abnormal growth of cancer within epithelial tissues. It can also occur in various other areas of the body, such as the breast, skin, trachea, lacrimal gland, uterus, cervix, and prostate.

Although adenoid cystic carcinoma is known for its slow growth, it is considered locally aggressive and has the potential to be fatal. The cancer can infiltrate the surrounding sheath or coating, enveloping nerve fibers within the perineural space. Microscopically, ACC appears as cords of abnormal cells surrounding or infiltrating glandular structures and ducts. These cells form cystic structures filled with a mucus-like material and exhibit irregular fibrous membranes, often referred to as hyaline

If symptoms do arise, they are contingent on the tumor’s location and size, including:

1. Salivary Gland: painless lump in the mouth, face, or neck; facial numbness; weakness in facial muscles; difficulty swallowing or opening the mouth.
2. Lacrimal Gland: Bulging eye; vision changes.
3. Larynx and Trachea: Hoarseness; changes in speech; difficulty breathing.
4. Skin: pain; increased sensitivity; pus and/or blood discharge.
5. Breast: slow-growing lump, possibly tender or causing pain.

Types

Adenoid cystic carcinoma is categorized based on its microscopic appearance, specifically the histologic variation of the tumor. The classification includes:

1. Cylindroma: This type of tumor is characterized by tube-shaped cells.
2. Cribriform: This tumor has a distinctive appearance resembling Swiss cheese, with gaps or spaces between the cells.

Causes of Adenoid Cystic Carcinoma

The exact cause of ACC remains unknown, leaning toward genetic changes occurring during an individual’s lifetime rather than hereditary factors.

Diagnosis of Adenoid Cystic Carcinoma

If ACC is suspected, a medical history review, a physical examination, and specific tests are conducted. Diagnostic tools include:

1. CT scan: detailed images of the body’s interior, with or without dye injection.
2. MRI: cross-sectional pictures provide insights into tumor extent.
3. PET Scan: By injecting a radioactive solution and then scanning the body, a PET scan can pinpoint areas of active cancer cell growth.
4. Ultrasound: soundwaves for imaging, a painless procedure.
5. Biopsy: removal of a small tissue sample for microscopic examination.

Treatment of Adenoid Cystic Carcinoma

A multidisciplinary healthcare team oversees ACC treatment, considering factors such as tumor location, spread, age, health, and patient preferences. Primary treatments encompass:

1. Surgery: effective for safely removable tumors, involving a wide local excision to reduce recurrence risk. Nerves and lymph nodes may be removed if involved.
2. Radiation therapy: high-energy rays targeting cancer cells, often applied post-surgery or as palliative treatment.
3. Chemotherapy: drug use to kill or slow cancer cell growth; not commonly used for ACC but considered in advanced cases.

Treatment Team for Adenoid Cystic Carcinoma

The diverse treatment team may include a GP, surgeon, radiation oncologist, medical oncologist, cancer nurse, speech pathologist, dietitian, and other allied health professionals.

Who are those at risk?

Adenoid cystic carcinomas (ACCs) strike individuals aged 40 to 60 the hardest, with a median age of 58. Women bear the brunt of this disease, making up 60% of patients, likely due to its higher prevalence in female-specific organs like the breasts and cervix. While ACC primarily targets adults, tragic cases have emerged in children and adolescents, particularly affecting the delicate tear glands (lacrimal glands).

Prognosis

Predicting the exact course of the ACC is challenging, depending on individual circumstances. Your doctor analyzes test results, tumor growth rate, age, fitness, and medical history to build a personalized prognosis.

Palliative Care

Doctors often discuss palliative care to proactively address symptom management, improved well-being, and comfort for patients with serious illnesses. It may involve radiotherapy, chemotherapy, or other drug therapies.