Diabetic Mastopathy / Lymphocytic Mastitis

Definition

• A fibrous breast mass witha prominent lymphocytic infiltrate most often occurring in patients with longstanding diabetes

Alternate/Historical Names

• Diabetic fibrous mastopathy
• Diabetic lymphocytic lobulitis
• Fibrous disease of the breast in juvenile diabetics
• Lymphocytic mastopathy
• Sclerosing lymphocytic lobulitis

Diagnostic Criteria

• Prominent keloidal fibrosis
• Prominent lymphocytic infiltrate
  • Perivascular, perilobular, periductal
    • May infiltrate lobular epithelium forming lymphoepithelial lesions
  • Sharply circumscribed infiltrate
  • May form nodules but germinal centers not seen
  • Predominantly B cells
  • One case reported of a postmenopausal patient with an exuberant lymphohistiocytic and granulomatous response (Fong 2006)
• Epithelioid stromal cells
  • No mitotic figures described in stromal cells
  • Variable staining for actin
• No epithelial proliferation
• Virtually all female patients premenopausal
• Nearly all reported cases with the full constellation of histologic features have occurred in diabetics

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

• Lymphoid infiltrate is predominantly B cells
  • No CD43 coexpression
• Epithelioid stromal cells
  • Variably reactive for actin
  • Negative for desmin, S100, CD34

Genetic analysis

• No evidence of B cell clonality

Differential Diagnosis

• Fibrocystic disease
• Nonspecific mastitis
• Mammary Hamartoma

Fibrocystic disease

• Combined epithelial and stromal process
• Lacks keloidal fibrosis
• Lacks epithelioid stromal cells
• Lacks characteristic B cell infiltrates

Nonspecific mastitis

• Mixed B and T cells or predominantly T cells
• Lacks keloidal fibrosis
• Lacks epithelioid stromal cells

Diabetic Mastopathy / Lymphocytic Mastitis	Mammary Hamartoma
Epithelioid stromal cells	No epithelioid stromal cells
Prominent B cell infiltrates	No significant B cell infiltrates

Both have keloidal fibrosis

Clinical

• Nearly all reported cases with full constellation of histologic features have occurrred in diabetics
  • Most often associated with Type I diabetes
  • One report of association with longstanding insulin use rather than type of diabetes (Seidman)
  • Occasional cases reported in non-diabetics with some but not all of the diagnostic histologic features
    • Significance of such lesions is unclear
    • Autoantibodies reported in some cases (Schwartz)
• Generally presents as a fibrous mass or masses
  • May be unilateral or bilateral
  • One prospective series of diabetics found non-palpable lesions with some but not all of the diagnostic histologic features (Lammie)
• Most patients female
  • Virtually all premenopausal
  • Rare male cases reported
• May recur

Bibliography

• Valdez R, Thorson J, Finn WG, Schnitzer B, Kleer CG. Lymphocytic mastitis and diabetic mastopathy: a molecular, immunophenotypic, and clinicopathologic evaluation of 11 cases. Mod Pathol. 2003 Mar;16(3):223-8.
• Ely KA, Tse G, Simpson JF, Clarfeld R, Page DL. Diabetic mastopathy. A clinicopathologic review. Am J Clin Pathol. 2000 Apr;113(4):541-5.
• Tomaszewski JE, Brooks JS, Hicks D, Livolsi VA. Diabetic mastopathy: a distinctive clinicopathologic entity. Hum Pathol. 1992 Jul;23(7):780-6.
• Schwartz IS, Strauchen JA. Lymphocytic mastopathy. An autoimmune disease of the breast? Am J Clin Pathol. 1990 Jun;93(6):725-30.
• Lammie GA, Bobrow LG, Staunton MD, Levison DA, Page G, Millis RR. Sclerosing lymphocytic lobulitis of the breast--evidence for an autoimmune pathogenesis. Histopathology. 1991 Jul;19(1):13-20.
• Morgan MC, Weaver MG, Crowe JP, Abdul-Karim FW. Diabetic mastopathy: a clinicopathologic study in palpable and nonpalpable breast lesions. Mod Pathol. 1995 May;8(4):349-54.
• Ashton MA, Lefkowitz M, Tavassoli FA. Epithelioid stromal cells in lymphocytic mastitis--a source of confusion with invasive carcinoma. Mod Pathol. 1994 Jan;7(1):49-54.
• Seidman JD, Schnaper LA, Phillips LE. Mastopathy in insulin-requiring diabetes mellitus. Hum Pathol. 1994 Aug;25(8):819-24.
• Fong D, Lann MA, Finlayson C, Page DL, Singh M. Diabetic (lymphocytic) mastopathy with exuberant lymphohistiocytic and granulomatous response: a case report with review of the literature. Am J Surg Pathol. 2006 Oct;30(10):1330-6.