Mucinous carcinomas
Mucinous carcinomas are a specific type of invasive cancer characterized by the production of mucus, known as mucin. They most commonly occur in the breast but can also be found in the colon, lungs, ovaries, uterus, pancreas, and rectum. There are two classifications: pure mucinous carcinoma, which consists solely of mucin-producing cancer cells, and mixed mucinous carcinoma, which contains other types of cancer cells. These carcinomas are relatively rare, accounting for about 7% of breast cancer diagnoses and varying percentages in other cancers, such as colon and lung cancers.
The average age of diagnosis varies by location; for instance, mucinous breast carcinoma is typically diagnosed around age 67, while mucinous skin carcinoma is found around age 63. Symptoms can differ based on the cancer's location, ranging from palpable breast tumors to painless skin nodules and gastrointestinal issues in colon cases. Diagnosis often involves biopsy techniques, and treatment may include surgery, hormone therapy, and chemotherapy, depending on the cancer's characteristics. Prognosis is generally favorable, particularly for mucinous carcinomas of the breast, which have high survival rates due to lower risks of lymph node involvement. However, mucinous carcinoma of the skin may have a higher chance of local recurrence.
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Subject Terms
Mucinous carcinomas
ALSO KNOWN AS: MC, Colloid carcinomas, mucinous adenocarcinomas, adenocystic carcinomas, mucoepidermoid carcinomas, gelatinous carcinomas, pure mucinous carcinomas (PMC), mixed mucinous carcinomas (MMC).
RELATED CONDITIONS: Breast cancers, in situ, colon cancer, pancreatic cancer, eyelid cancer, adenocarcinoma
DEFINITION: Mucinous carcinoma is a type of invasive duct cancer that occurs most frequently in the breast (MCB) but may occur in the colon, lungs, ovaries, uterus, pancreas, or rectum. Primary mucinous carcinoma of the skin (MCS) is a rare variant of a sweat gland tumor. If only mucinous cancer cells are present, the condition is called pure mucinous carcinoma, but if other cancer cells are also present, it is called mixed mucinous carcinoma.
Risk factors: The average age at diagnosis is sixty-seven for mucinous carcinoma of the breast and sixty-three for mucinous carcinoma of the skin. Other factors include alcohol and tobacco use, weight, and activity level.
Etiology and the disease process: In all cases, the distinguishing feature is mucus production called mucin. Poorly differentiated cancer cells are often completely surrounded by mucin in these tumors. The cancer spreads into the normal tissue surrounding it, although the mucin itself does not generally cause major problems.
Incidence: Mucinous carcinoma of the breast is a relatively rare form that accounts for about 7 percent of all breast cancer diagnoses. It occurs most frequently in women in their sixties. Mucinous carcinoma of the skin can originate at any location on the body, although the eyelid has been reported as the most commonly affected area (41 percent of cases). There is a slight preponderance of affected males. Mucinous carcinoma also accounts for 3 percent of ovarian, 5 percent of lung, 9 percent of rectal, 10 percent of uterine, and 15 percent of colon cancer diagnoses.
Symptoms: Mucinous carcinoma of the breast is usually detected as medium to large tumors that can be felt. They are usually highly estrogen-dependent and only rarely spread to local lymph nodes. Mucinous carcinoma of the skin lesions are painless gray or red nodules measuring 0.5 to 7 centimeters in diameter. Other symptoms in breasts include pain in the breast or armpit, nipple discharge, and skin swelling or dimpling. In the colon, symptoms include abdominal pain, constipation, diarrhea, weight loss, or blood in stool. In the lungs, symptoms include headache, coughing up blood, cough, and chest pain.
Screening and diagnosis:Core needle biopsy (of the breast version) and skin biopsy (of the skin version) are usually very effective diagnostic tools. Tumor identification is most often straightforward since tumor cell morphology and mucin production are characteristic of this type of cancer.
Treatment and therapy: Treatment of mucinous carcinoma of the breast generally includes some combination of surgery, hormone therapy, immunotherapy, chemotherapy, and radiation therapy. Since lymph node involvement is rare, surgery can often be conservative (lumpectomy). The standard treatment for mucinous carcinoma of the skin is wide local excision.
Prognosis, prevention, and outcomes: Mucinous carcinoma of the breast has a much better prognosis than other invasive ductal breast carcinomas because it is associated with a low risk of axillary metastases. A ten-year survival rate of more than 90 percent has been reported. Mucinous carcinoma of the skin lesions has a propensity for local recurrence and regional spread, although distant metastases are rare. One study of one hundred cases of primary mucinous carcinoma of the skin reported 29.4 percent local recurrences, 9.6 percent metastases, and an overall mortality rate of 2 percent. Further research confirmed the low mortality rate finding, with some studies finding a 100 percent five-year survival rate.
Bibliography
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Kelemen, Linda E., and Martin Kobel. "Mucinous Carcinomas of the Ovary and Colorectum: Different Organ, Same Dilemma." Lancet Oncology, vol. 12, no. 11, 2011, pp. 1071–80. doi:10.1016/S1470-2045(11)70058-4.
Marrazzo, Emilia, et al. “Mucinous Breast Cancer: A Narrative Review of the Literature and a Retrospective Tertiary Single-Centre Analysis.” Breast (Edinburgh, Scotland), vol. 49, 2020, pp. 87-92. doi:10.1016/j.breast.2019.11.002.
"Mucinous Carcinoma." Cleveland Clinic, 5 Feb. 2022, my.clevelandclinic.org/health/diseases/22975-mucinous-carcinoma. Accessed 20 June 2024.
Nguyen, B., et al. "The Genomic Landscape of Carcinomas with Mucinous Differentiation." Scientific Reports, vol. 11, 2021. doi.org/10.1038/s41598-021-89099-2.