Lobular carcinoma in situ

Classification according to ICD-10
D05.0	Lobular carcinoma in situ of the mammary gland
ICD-10 online (WHO version 2019)

The lobular carcinoma in situ (engl. Lobular carcinoma in situ , LCIS , often carcinoma lobular in situ , CLIS or lobular neoplasia , LN or Lobular intraepithelial neoplasia , LIN ) is a proliferation of neoplastic cells in the lobules of Brüstdrüse that the Milk ducts can spread. It is a non-invasive carcinoma of the female breast (which does not grow into the surrounding tissue ) . Although LCIS to "place" ( in situ ) is, it can become an invasive breast cancer develop. The lobular carcinoma in situ is therefore a risk factor for the development of breast cancer .

The LCIS occurs in about 46 to 85 percent of all cases multicenter (in several different places on the breast), in about 30 to 67 percent of all cases bilaterally (on both sides) and before, rather than after, menopause .

Epidemiology

The proportion of non-invasive carcinomas of the LCIS is around 5%, depending on the source.

Symptoms

The LCIS usually does not produce any symptoms and occurs as an incidental finding during a biopsy (e.g. biopsy in mammography screening).

diagnosis

Since this in-situ carcinoma rarely forms microcalcifications , it usually cannot be diagnosed by mammography . It is neither visible to the naked eye nor palpable. Diagnosis is only possible with the help of a histological examination by a pathologist .

Histological features of the LCIS forms

The WHO classification of tumors distinguishes between three different forms of LCIS, which are summarized under the generic term lobular neoplasia: atypical lobular hyperplasia (ALH), carcinoma lobulare in situ (CLIS) and carcinoma lobulare in situ of the extended ("extended") type .

In atypical lobular hyperplasia , the neoplastic cells remain confined to the lobule and the architecture of the lobule is not changed. The CLIS is defined by a widening of the lobules that are filled with large amounts of neoplastic cells. In the CLIS extended type , the lobules are also widened by tumor cells. However, these are already spreading into the milk ducts .

With the CLIS and the CLIS extended type in particular, necrosis and microcalcifications can also occur , albeit rarely .

Some pathologists classify the LCIS according to the LIN classification ( Lobular Intraepithelial Neoplasia ). A LIN1 corresponds to the ALH, a LIN2 to the CLIS, and a LIN3 to the CLIS extended type.

TNM classification

In the TNM classification , the LCIS receives the classification Tis (for i n s itu) with the addition (LCIS) .

Therapy and prognosis

There is no general therapy recommendation for LCIS, especially because this term encompasses a heterogeneous (“non-uniform”) group of different lesions.

Several factors must be taken into account during treatment:

• The three subtypes of LCIS have a different risk of progressing to invasive carcinoma. Corresponding studies showed an increased risk for the CLIS and the CLIS extended type, but not for the atypical lobular hyperplasia.
• Up to 85% of all LCIS are multicentric and up to 67% occur simultaneously in both breasts.
• There are no imaging methods that can be used to make an LCIS visible. There is also no way of obtaining information about the extent of the neoplasm through clinical or serological examinations.

Until a few years ago, only the last two points were known in the treatment decision. As a result, the affected women had a bilateral mastectomy . Nowadays there is no longer any recommendation to do this. Only with the CLIS extended type should a complete removal of the affected area be considered. The vast majority of women therefore do not have an operation, but should undergo close clinical and mammographic control.

See also

• Ductal carcinoma in situ

Individual evidence

1. ↑ ^{a b} S3-guideline for breast cancer of the Dt. Cancer Society ( Memento from January 18, 2012 in the Internet Archive ) (PDF; 1.7 MB) p. 27.
2. ↑ WHO Classification of Tumors: Pathology and Genetics of Tumors of the Breast and Female Genital Organs (Who / IARC 2003) ISBN 9283224124 pp. 60-62
3. ^ WHO-Classification of Tumors: Pathology and Genetics of Tumors of the Breast and Female Genital Organs (Who / IARC 2003) ISBN 9283224124 p. 62
4. ^ WHO-Classification of Tumors: Pathology and Genetics of Tumors of the Breast and Female Genital Organs (Who / IARC 2003) ISBN 9283224124 p. 62

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