Focal Pregnancy-like Change of the Breast

Definition

• Focal lactational change in a non-lactating, non-pregnant patient

Alternate/Historical Names

• Focal lactational change
• Pseudolactational change
• Focal lactating effect

Diagnostic Criteria

• The patient must be currently non-lactating and non-pregnant
  • May be of any age
• Dilated acini lined by abundant pale vacuolated cytoplasm
  • Lumenal cytoplasmic blebs
  • Nuclei frequently contained in apical blebs
• Nuclei typically small, round, uniform
  • Four cases reported with cytologic atypia, of unknown clinical significance (Shin)
    • Increased nucleo/cytoplasmic ratio, pleomorphic nuclei, large nucleoli, mitoses identified
    • Micropapillary architecture
    • All four cases had associated cystic hypersecretory hyperplasia
• Intraluminal calcifications described (Shin)
  • Smooth contours, frequent eosinophilic border, uneven laminations
  • “Precalcified” laminated proteinaceous deposits described

Richard L Kempson MD
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342

Original posting: May 15, 2006

Supplemental studies

Immunohistology

• none

Differential Diagnosis

Lactating Adenoma	Focal Pregnancy-like Change
Circumscribed mass	Focal change in breast parenchyma

Clinical

• Generally considered an incidental finding
  • 12 cases reported associated with calcification or other mammographic abnormality (Shin)
• May follow pregnancy by 3-24 years
  • Occasionally no history of pregnancy
  • Patient may be of any age
• May be associated with drug therapy (Tavassoli)
  • Hormones
    • Reported in males receiving estrogen for prostate carcinoma
  • Antipsychotic drugs
  • Antihypertensive drugs
• Benign, no association with carcinoma

Bibliography

• Mills SE, Fraire AE. Pregnancy-like change of the breast. An ultrastructural study. Diagn Gynecol Obstet. 1981 Fall;3(3):187-91.
• Mills SE, Fechner RE. Focal pregnancy-like change of the breast. Diagn Gynecol Obstet. 1980 Spring;2(1):67-70.
• Kiaer HW, Andersen JA. Focal pregnancy-like changes in the breast. Acta Pathol Microbiol Scand [A]. 1977 Nov;85(6):931-41.
• Tavassoli FA, Yeh IT. Lactational and clear cell changes of the breast in nonlactating, nonpregnant women. Am J Clin Pathol. 1987 Jan;87(1):23-9.
• Shin SJ, Rosen PP. Pregnancy-like (pseudolactational) hyperplasia: a primary diagnosis in mammographically detected lesions of the breast and its relationship to cystic hypersecretory hyperplasia. Am J Surg Pathol. 2000 Dec;24(12):1670-4.