Carcinosarcoma

Image credit: Figure- Representative images showing islands of an adenocarcinoma with a cribriform architecture (A-C). The stroma comprised atypical whorls and fascicles of spindle cells (A-D) with perineural invasion (D). Diffuse CK7 staining (E) was only seen in carcinoma islands whereas Ki-67 (E) showed a proliferation index of approximately 10%. Images provided by Professor Ali Khurram (Sheffield).

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Carcinosarcoma

Carcinosarcoma is a very rare and aggressive type of salivary gland cancer. It accounts for less than 1% of all salivary gland tumours [1]. Unlike most other salivary gland cancers, carcinosarcoma contains two different types of cancer cells: carcinoma (originating from epithelial cells that line salivary ducts) and sarcoma (originating from supportive tissues, including connective tissue and muscle etc.)[2].

Because of its rarity and complexity, carcinosarcoma can be challenging to diagnose and treat. It tends to behave more aggressively than many other salivary gland cancers and can spread quickly [2, 3].

Carcinosarcoma most often arises in the parotid gland, the largest of the major salivary glands, located in front of the ear. Less commonly, it can occur in the submandibular or minor salivary glands [2, 3].

It usually occurs in older adults, most commonly between the ages of 60 and 80, and appears to affect men and women equally [3, 4].

There are two types of carcinosarcoma:

• De novo carcinosarcoma, which arises on its own
• Carcinosarcoma ex pleomorphic adenoma, which develops from a pre-existing benign tumour called a pleomorphic adenoma that has transformed into cancer over time [1, 3]

Because carcinosarcoma is so rare, the exact causes are still not well understood. Some cases appear to arise from long-standing pleomorphic adenomas, especially when these have not been surgically removed. Over time, genetic changes can cause the benign tumour to become cancerous [3, 5].

Symptoms depend on the location and size of the tumour but may include:

• A rapidly growing lump in the jaw, cheek, or mouth
• Pain or discomfort
• Facial nerve weakness or paralysis (especially if the tumour is in the parotid gland)
• Difficulty swallowing or speaking
• Ulceration or invasion of nearby tissues in advanced cases [1, 4]

Because this cancer tends to grow quickly, symptoms often appear and progress over a relatively short time.

Diagnosis typically involves:

• A physical examination and review of symptoms
• Imaging scans such as MRI or CT to assess the tumour’s size, spread, and involvement of nearby structures
• A biopsy, where a small tissue sample is taken for analysis under the microscope [5]

Carcinosarcoma is usually diagnosed by identifying both the carcinoma and sarcoma components in the same tumour. This may require additional immunohistochemical and molecular testing to confirm [2, 6].

Due to its aggressive nature, carcinosarcoma is usually treated with a combination of surgery and radiotherapy, and in some cases chemotherapy may be added [3, 6].

Because carcinosarcoma has a high risk of local recurrence and spread to other parts of the body (often to the lungs, liver, or bones), different specialists may have to work together to plan treatment.

Long-term follow-up and monitoring are essential, as recurrences can occur even after apparently successful treatment.

References

1. Alsanie I, Shah KA, Adkins DR, et al. Distribution and Frequency of Salivary Gland Tumours: An International Multicenter Study. Head Neck Pathol. 2022;16(4):1043–1054.
2. Gnepp DR, Bishop JA, eds. Diagnostic Surgical Pathology of the Head and Neck. 3rd ed. Philadelphia: Elsevier; 2021.
3. Seethala RR. An Update on Grading of Salivary Gland Carcinomas. Head Neck Pathol. 2009;3(1):69–77.
4. Lewis JE, Olsen KD, Sebo TJ. Carcinosarcoma of the major salivary glands: clinicopathologic and immunohistochemical review of 18 cases. Am J Surg Pathol. 2001;25(6):793–800.
5. Tortoledo ME, Luna MA, Batsakis JG. Carcinosarcoma of major salivary glands. Ann Otol Rhinol Laryngol. 1984;93(3):263–266.
6. Bell D, El-Naggar AK. Molecular heterogeneity in salivary gland carcinosarcoma: diagnostic implications. Curr Oncol Rep. 2016;18(3):15.
7. National Comprehensive Cancer Network (NCCN). NCCN Clinical Practice Guidelines in Oncology: Head and Neck Cancers, Version 2.2024. Plymouth Meeting, PA: NCCN; 2024.