Australian Society of CytologyCase of the Month
January 2003 - Answer and Discussion
Tubular Adenoma
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Lower power histology |
High power histology |
Smooth muscle actin stain |
Discussion
Multinucleated stromal giant cells have been described in various sites, in particular within the stroma of fibroepithelial polyps of the lower female genital tract and also within the subepithelial stromal of the lower female genital tract and within fibroepithelial polyps of the nose, anus and bladder. Rosen first described mammary multinucleated stromal giant cells similar to those noted in this case in 1979. These cells were an incidental finding within the interlobular stroma of breast tissue removed for carcinoma as well as in biopsies performed for benign conditions. They were felt to represent a non-neoplastic and possibly reparative process.
More recently, atypical and bizarre multinucleated giant cells have been identified within the stroma of otherwise typical fibroadenoma. Tubular adenoma is a biphasic, benign neoplasm similar to fibroadenoma with a more predominant epithelial component. The giant cells of fibroadenomata may be present focally or diffusely and are benign and of no prognostic significance. They have been variously described as being of epithelial or stromal origin. The immunohistochemical studies performed in this case showed focal scanty positive cytoplasmic staining with smooth muscle actin and negative reactions with keratins, CD68 and S100, which would appear to support a myofibroblastic origin.
In retrospect, the cytological features of this case correspond exactly with the histological appearance. It is important to be aware of this benign condition to avoid confusion with a malignant lesion. Cytological clues as to the benign nature of this lesion lie in the presence of clearly benign elements including naked bipolar nuclei and sheets of benign epithelial cells and the overall pattern which is highly suggestive of a benign biphasic tumour such as a fibroadenoma.
FURTHER READING:
- Clement P. Multinucleated stromal giant cells of the uterine cervix. Arch Pathol Lab Med 1985; 109: 200-202.
- Elliott G, Elliott J. Superficial stromal reactions of the lower genital tract. Arch Pathol 1973; 95: Feb 100-001.
- Rosen P. Multinucleated mammary stromal giant cells. Cancer 1979; 44: 1305-1308.
- Tavassoli F. Pathology of the breast. Appleton and Lange. Norwall Connecticut. 1992; 120-128. 425-441.
- Nielsen B. Ladefoged C. Fibroadenoma of the female breast with multinucleated giant cells. Path Res Pract 1985; 180: 721-724.
- Berean K, Tron V, Churg A, Clement P. Mammary fibroadenoma with multinucleated stromal giant cells. Am J Surg Pathol 1986; 10(11): 823-827.
- Wai-Kuen Ng. Fine needle aspiration cytology of fibroadenoma with multinucleated stromal giant cells. Acta Cytol 2002; 46(3): 535-539.
