22 February 2006 – Case of the Week #37
These cases can also be accessed by clicking on the Case of the Week button on the left hand side of our Home Page at www.PathologyOutlines.com. This email is sent only to those who subscribe in writing or by email. To view the images or references, you must click on the links in blue.
To subscribe or unsubscribe, email info@PathologyOutlines.com, indicating subscribe or unsubscribe to Case of the Week. We do not sell, share or use your email address for any other purpose. We also maintain two other email lists: to receive a biweekly update of new jobs added to our Jobs page, and to receive a monthly update of changes made to the website. You must subscribe or unsubscribe separately to these email lists.
Advertise your openings for pathologists or pathology related positions on our fantastic Jobs page. With over 14,000 visits per month, we provide tremendous traffic and results, all for one low price. Instead of charging you month after month, we charge only $600 (US) for posting text and an optional logo for a single Pathologist position, until it is filled, up to one year, or $750 for two or more positions in the same ad. In addition, we provide exceptional customer service. Simply email your text to email@example.com and we will bill you.
We thank Dr. Lisa A. Cerilli, University of New Mexico Health Sciences, Albuquerque, New Mexico (USA), for contributing this case and the discussion. We invite you to contribute a Case of the Week by sending an email to NPernick@PathologyOutlines.com with microscopic images (any size, we will shrink if necessary) in JPG or GIF format, a short clinical history, your diagnosis and any other images (gross, immunostains, EM, etc.) that you have and that may be helpful or interesting. We will write the discussion (unless you want to), list you as the contributor, and send you a check for $35 (US) for your time after we send out the case. Please only send cases with a definitive diagnosis.
Case of the Week #37
A 49 year old healthy woman underwent needle localization excision of a breast mass for biopsy proven low grade ductal carcinoma in situ. A 9 mm lesion was identified histologically adjacent to, but not involved by, multifocal DCIS. The epithelial component in the nodule showed the typical cytoarchitecture of fibroadenoma, but also had some atypical cells. No mitotic figures were found.
What is your diagnosis?
(scroll down to continue)
Fibroadenoma with bizarre stromal giant cells (for this portion of the specimen)
microscopic images show stromal cells with markedly enlarged and hyperchromatic,
pleomorphic nuclei. Many of the stromal cells showed multinucleated forms or
prominent round, intranuclear pseudoinclusions. The remaining breast showed
foci of DCIS with low grade nuclear features, which of course was included
within the final diagnosis.
Well-defined histological parameters typically are reliable indicators to differentiate benign from malignant entities. The presence of enlarged and pleomorphic nuclei is classically regarded as a feature of malignancy, but may on occasion be evident in lesions with completely benign behavior. This discordance between nuclear atypia and behavior is characteristically encountered in uterine leiomyomas (referred to as “symplastic” change), or schwannomas (described as “ancient change”). Degenerative type atypia has also been described in osteoblastoma, chondromyxoid fibroma, fibrodysplasia, renal oncocytoma, stromal hyperplasia of the prostate, endometrial polyps, and salivary polymorphic adenoma (1-4), as well as in endocrine neoplasms. Similar nuclear changes arising in mammary fibroadenomas are only seen rarely.
Architecturally, the overall pattern of fibroadenoma with bizarre stromal giant cells is that of the usual fibroadenoma, but with diffuse striking nucleomegaly of the stromal cells, accompanied by adequate cytoplasm. Mitotic figures are notably absent. Other neoplastic lesions in the breast that show atypical stromal cells include phyllodes tumor, sarcoma, and metaplastic breast carcinoma. Distinction from these other lesions can be made by recognition of the lack of stromal overgrowth, cellular crowding and mitotic figures, and most importantly, the lack of crisp nuclear details (i.e. the chromatin is “smudgy”). The presence of multinucleated giant cells in combination with mitotic activity, necrosis, stromal overgrowth or hypercellularity raises the question of another lesion, usually phyllodes tumor (5). The degree of atypia in fibroadenoma with bizarre stromal giant cells actually exceeds that which typifies malignant processes in the breast, another diagnostic clue.
Bizarre nuclear alteration in the presence of abundant cytoplasm may also be seen following external beam radiation therapy. Due to radiation-induced inhibition of cell division, the nucleus becomes enlarged, acquiring bizarre features including pseudoinclusions. Unlike radiation effect, fibroadenoma with bizarre stromal giant cells shows no epithelial or vascular abnormalities, the atypia is well-localized, and there is no history of radiation exposure.
Fibroadenoma with bizarre stromal cells is an uncommon benign entity in the breast which can be easily confused with phyllodes tumor or other lesions with malignant stromal cells, particularly in fine needle aspirations (6). The bizarre nuclear changes are related to degenerative alterations, and they do not indicate aggressive or malignant behavior. Treatment is conservative local excision, which is completely curative.
30100 Telegraph Road, Suite 404
Bingham Farms, Michigan (USA) 48025