microinvasion


Also found in: Dictionary, Encyclopedia.

microinvasion

 [mi″kro-in-va´zhun]
microscopic extension of malignant cells into adjacent tissue in carcinoma in situ. adj., adj microinva´sive.

mi·cro·in·va·sion

(mī'krō-in-vā'zhŭn),
Invasion of tissue immediately adjacent to a carcinoma in situ, the earliest stage of malignant neoplastic invasion.

microinvasion

A generic term for an epithelial malignancy in which the basement membrane has been minimally violated. As a rule, microinvasive cancers measure 1 mm or less in greatest dimension and are designated as Tmic, prognostically between T0 (carcinoma in situ) and T1a in the TNM system. It is also defined as > 1 focus of cancer measuring 2 mm or less in diameter.

mi·cro·in·va·sion

(mī'krō-in-vā'zhŭn)
Invasion of tissue immediately adjacent to a carcinoma in situ, the earliest stage of malignant neoplastic invasion.
References in periodicals archive ?
Patterns of stromal invasion in ovarian serous tumors of low malignant potential (borderline tumors): a reevaluation of the concept of stromal microinvasion. Am J Surg Pathol.
Control rats without adult hormones showed no lesion progression whereas controls with T + E exhibited limited cancerous progression with a 17% incidence of microinvasion, the earliest recognizable form of prostate cancer as evidenced by basement membrane breakdown with epithelial cells invading the stroma (Bostwick 1996; Bostwick and Cheng 2012).
Interpretational errors include overdiagnosis of benign lesions as DCIS (for example, florid usual hyperplasia) or underdiagnosis of invasive carcinoma (for example, when microinvasion is overlooked or when invasive cribriform carcinoma is not recognized).
Nodal disease is often an indication of microinvasive or invasive foci present within the tumour and is rare in pure DCIS tumours, where it may signify the presence of occult microinvasion. The presence of nodal disease may warrant consideration for more aggressive systemic therapy in view of the potentially higher risk of disease recurrence and systemic metastasis [4,5].
TN-C has also been regarded as a potential marker for microinvasion in DCIS by some authors [22-25].
In addition, this Multiplex IHC test is particularly useful to reduce false negatives and false positives for microinvasion; when there are overlapping features of lobular carcinoma in situ and ductal carcinoma in situ in a lesion; when there is necrosis potentially masking microinvasion; to differentiate higher nuclear grade LCIS patients such as pleomorphic lobular carcinoma in situ which may mimic DCIS; and in LCIS samples where LCIS cells grow into a duct, or the lobule becomes distended so that its appearance is similar to a duct, making the differentiation of LCIS and DCIS more challenging."
those of mammary Paget's disease ascend to the epidermis from lactiferous ducts, whereas those of EMPD originate in the epidermis itself.8 The level of invasion of Paget's cells in EMPD can be classified into three grades: in situ in epidermis, microinvasion into the papillary dermis and deep invasion into the reticular dermis or subcutaneous tissue.9 According to this classification our case can fall into the third grade.
All 3 tumors with thyroid cartilage microinvasion were staged as T2 lesions either before radiotherapy started or after showing evidence of recurrence or persistent disease.
(1) In the mural unicystic ameloblastoma there is microinvasion of the underlying connective tissue with the majority of the lesion being confined to the cystic lumen.
Japanese pathologists generally utilize Elastic-van Gieson (EvG) staining and D2-40 immunostaining for characterization of microinvasion, which dramatically increases the ability to identify lymphatic and venous invasion (21).
Tumor microinvasion was found in one woman who had shown a partial response, and carcinoma developed in two other patients 2.5 and 3.5 years after vaccination (N.