Breast - Sein

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  Femme de 52 ans, lésion mammographique suspecte, biopsies à l'aiguille.   52 yo female, suspicious lesion on mammography, trucut biospies.  
  PAS   PAS  
  CK14   CK14  
  CK14   GCDFP15  
  CK Haut poids moléculaire (34b E12)   CK HMW (34b E12)  
  34b E12      

Diagnostic proposé








Adenose apocrine (adenomyoépithéliale).


Proposed diagnosis








Adenomyoepithelial (apocrine) adenosis

  Arguments   Clues  
  Ref Rosai and Ackerman’s Surgical Pathology (10th Ed.)  
  Microglandular and adenomyoepithelial (apocrine) adenosis.  

Adenomyoepithelial (apocrine) adenosis is a form of adenosis sharing some features with microglandular adenosis, and perhaps representing a variant of it, in which the glands are larger, the lining epithelium is taller and with apocrine metaplasia, and myoepithelial cells are present. The latter can be prominent and sometimes accompanied by nuclear atypia and nucleolar prominence (atypical apocrine adenosis). Apocrine adenosis has been found to be a clonal process. It is said to be associated with an increased risk for the development of carcinoma in women over the age of 60 years when accompanied by atypia, but doubts have been expressed about this claim and the very validity of the entity. An interesting aspect of this lesion is that it can give rise to a biphasic breast tumor that has been designated adenomyoepithelioma.


Microglandular adenosis, also known as microglandular hyperplasia, is a rare form of adenosis in which small uniform glands with open lumina containing an eosinophilic secretion are distributed in an irregular fashion within fibrous tissue or fat. There is no trabecular bar formation. The glands are lined by a single layer of small uniform cuboidal or flat cells with vacuolated or granular cytoplasm, lacking apocrine-type ‘snouts’. In contrast to other forms of adenosis, the myoepithelial layer is absent.However, there is a thick basement membrane that can be well appreciated immunohistochemically and ultrastructurally. The stroma may be hyalinized but is not cellular or elastotic. The main differential diagnosis of this lesion is with tubular carcinoma. Microglandular adenosis is an indolent condition and should be treated conservatively; however, enough cases have been reported in continuity with carcinoma to suggest that it may evolve into malignancy with a frequency greater than the other forms of adenosis described in this section. Interestingly, a high percentage of these carcinomas in one series have been interpreted as being of the adenoid cystic type. Actually, this frequently occurring spatial relationship with an easily recognizable carcinoma, and the fact that microglandular adenosis is the only benign epithelial breast lesion devoid of myoepithelial cells, makes one wonder whether it may not represent an extremely low-grade form of ductal carcinoma with a very indolent clinical course. At the very least, it should be considered to be a lesion having a significant premalignant potential.

  Atypical Apocrine Adenosis of the Breast (click to view)
A Clinicopathologic Study of 37 Patients with 8.7- Year Follow-Up
  Atypical apocrine adenosis of the breast: long-term follow-up in 37 patients.  


CONTEXT:Atypical apocrine adenosis is a rare breast lesion in which the cellular population demonstrates cytologic alterations that may be confused with malignancy. The clinical significance and management of atypical apocrine adenosis are unclear because of the lack of long-term follow-up studies.

OBJECTIVE:To determine the breast cancer risk in a retrospective series of patients with atypical apocrine adenosis diagnosed in otherwise benign, breast excisional biopsies.

DESIGN:We identified 37 atypical apocrine adenosis cases in the Mayo Benign Breast Disease Cohort (9340 women) between 1967 and 1991 with a blinded pathology rereview. Breast cancer diagnoses subsequent to initial atypical apocrine adenosis biopsy were identified (average follow-up, 14 years).

RESULTS:The mean age at diagnosis of atypical apocrine adenosis in the group was 59 years. Breast carcinoma subsequently developed in 3 women (8%) with atypical apocrine adenosis, diagnosed after follow-up intervals of 4, 12, and 18 years. The tumor from 1 of the 3 cases (33%) was ductal carcinoma in situ, contralateral to the original biopsy, and the other 2 cases (66%) were invasive carcinoma. Ages at the time of diagnosis of atypical apocrine adenosis were 55, 47, and 63 years for those that developed in situ or invasive carcinoma.

CONCLUSIONS:(1) Atypical apocrine adenosis was a rare lesion during the accrual era of our cohort (<1% of cases); (2) women found to have atypical apocrine adenosis were, on average, older than were other patients with benign breast disease, however, there does not seem to be an association with age and risk for developing carcinoma in patients diagnosed with atypical apocrine adenosis, as previously suggested; and (3) atypical apocrine adenosis does not appear to be an aggressive lesion and should not be regarded as a direct histologic precursor to breast carcinoma.