Journal of Cytology
Home About us Ahead of print Instructions Submission Subscribe Advertise Contact e-Alerts Login 
Users Online:55
  Print this page  Email this page Small font sizeDefault font sizeIncrease font size

CASE REPORT Table of Contents   
Year : 2010  |  Volume : 27  |  Issue : 4  |  Page : 149-151
Osseous differentiation in cystosarcoma phyllodes - diagnosed by fine needle aspiration cytology

Department of Pathology, VIMS, Bellary, India

Click here for correspondence address and email

Date of Web Publication27-Nov-2010


Osseous differentiation within a phyllodes tumor is extremely rare. Cytological and histological findings of a case of malignant phyllodes tumor with osseous differentiation are presented. A 45-year-old female had a malignant phyllodes tumor with osseous stroma diagnosed by fine needle aspiration cytology. The cytological findings were representative of the histological features. The diagnosis of these tumors preoperatively is important in planning the most appropriate treatment. It is also important to follow up these patients postoperatively for long periods for recurrence and metastasis.

Keywords: Cystosarcoma phyllodes; phyllodes tumor; Osseous differentiation; fine needle aspiration cytology

How to cite this article:
Krishnamurthy J. Osseous differentiation in cystosarcoma phyllodes - diagnosed by fine needle aspiration cytology. J Cytol 2010;27:149-51

How to cite this URL:
Krishnamurthy J. Osseous differentiation in cystosarcoma phyllodes - diagnosed by fine needle aspiration cytology. J Cytol [serial online] 2010 [cited 2022 Oct 1];27:149-51. Available from:

   Introduction Top

Phyllodes tumor - cystosarcoma phyllodes - is an uncommon mammary tumor with heterogenous histology consisting of both epithelial and stromal components. The cellularity of its connective tissue component is the most important feature distinguishing it from fibroadenoma. A small percentage of tumors are histologically overtly malignant, constituting less than ten percent of all phyllodes tumors. [1] Osseous differentiation is an extremely rare stromal alteration in phyllodes tumor causing histologic complexity. Preoperative diagnosis of these tumors by fine needle aspiration cytology (FNAC) and identification of overtly malignant tumor can help in planning the extent of surgery.

A case of phyllodes tumor with osseous differentiation is reported.

   Case Report Top

A 45-year-old woman presented with slowly progressive palpable mass of seven years duration in the upper outer and inner quadrant of the left breast measuring 10Χ6Χ5 cm, It was non-tender, mobile, not fixed to the skin or the underlying chest wall. It was of variable consistency with cystic firm and hard areas. There was no nipple retraction or enlarged lymph nodes. The general physical and systemic examination was within normal limits.

The routine investigations were done and found to be normal. Fine needle aspiration of the lesion was performed.

The cytological evaluation suggested a phyllodes tumor (high grade) with osseous stroma. Simple mastectomy was performed and the histologic diagnosis was malignant phyllodes with osseous differentiation.

Cytological evaluation of hematoxylin and eosin stained smears revealed a cellular aspirate containing epithelial and stromal fragments [Figure 1]. The epithelial components consisted of frond like groups of cohesive ductal epithelial cells resembling those seen in benign tumors. The cells within the groups were uniform with round to oval nuclei, fine chromatin and scant to moderate cytoplasm. The stromal component that predominated the smears consisted of leaf-like stromal fragments within a myxoid stroma. Individual mesenchymal cells with a spindle-shaped nucleus and occasional stromal fragments showed capillary vessels traversing over them were also seen. The spindle-shaped cells showed nuclear atypia. Amidst stromal fragments were seen eosinophilic amorphous and finely fibrillar material which represented the osseous stroma. It was also seen as thin intracellular strands within a cell cluster resembling osteoblasts with eccentrically placed round nucleus with central nucleolus and dense cytoplasm [Figure 2]. A cytological diagnosis of phyllodes tumor (high grade) with osseous stroma was suggested.
Figure 1 :Smears showing tightly cohesive clusters of benign ductal epithelial cells and leaf-like stromal fragments with scattered osteoid in the background (H and E, ×100)

Click here to view
Figure 2 :Smears showing amorphous and dense osteoid matrix along with scattered pleomorphic mesenchymal cells (H and E, ×400)

Click here to view

A simple mastectomy was performed and the specimen was subjected to histopathological examination.

Grossly the mastectomy specimen was covered by an elliptical bit of skin with nipple and areola measuring 12Χ12Χ8 cm. An irregular cystic mass was seen 2 cm from the nipple measuring 5Χ4 cm, which drained 10 ml of blood mixed fluid. Cut section through the nipple revealed an ill-defined grey white mass showing a variegated appearance with cystic, friable and solid areas. Adjacent to this was seen a well-defined hard glistening region 4 cm in diameter [Figure 3].
Figure 3 :Cut section of mastectomy specimen showing cystic, solid, and osseous areas

Click here to view

Microscopically the tumor was composed of a biphasic pattern consisting of epithelial and stromal fragments. The ductal components were benign. The stromal elements were predominant, arranged in interlacing fascicles and whorls. The cells showed marked pleomorphism, cellular atypia, multinucleated forms and abnormal mitosis [Figure 4]. Areas of osteoid matrix with osteoblasts were seen amidst the pleomorphic stromal components [Figure 4]. The final diagnosis of malignant phyllodes tumor with osseous differentiation involving the left breast was made.
Figure 4 :Sections showing sarcomatous stroma and osseous stroma with benign epithelial ductal component (H and E, ×400)

Click here to view

   Discussion Top

Phyllodes tumors of the breast are rare neoplasms accounting for less than 1% of breast tumors, 2-3% of mammary fibroepithelial neoplasms and 1.5% of all breast carcinomas. [1],[2] Malignant phyllodes tumors are rare ones comprising 0.18% of all breast malignancies. [3] They occur most often in 30-70 year-old females, the median age at the time of diagnosis being 45 years with a few occurring in adolescents. [4] These tumors present as discrete palpable masses with rapid enlargement. They are characterized by a tendency for local recurrence and extreme rarity of a distant metastasis. The phyllodes tumor is a tumor of specialized mammary stroma with a capacity for epithelial induction.

The value of FNAC in the diagnosis of phyllodes tumor is variable and the accuracy ranges from 25 to 70%. [5] A cytological diagnosis of phyllodes tumor is suggested by the presence of epithelial and stromal elements, the stroma presenting as cellular leaf-like fragments and isolated mesenchymal cells. [6] The stromal overgrowth is an important criterion for the diagnosis of malignancy in phyllodes tumor. [8] The parameters suggesting malignancy are extreme paucity of epithelial elements, and stromal cells in diffuse sheets and less cohesive clusters with marked stromal atypia and mitotic activity.

The cytological smears from phyllodes tumors share many similarities with those of fibroadenoma causing difficulty in diagnosis. The presence of large cells low epithelial / stromal ratio, benign nature of epithelial elements and stromal atypia favors a diagnosis of phyllodes tumor. [5]

Cystosarcoma phyllodes can have heterologous stromal components consisting of bone, cartilage, smooth muscles or fat. [8] The neoplastic stromal components is highly pleomorphic reminiscent of fibrosarcoma, malignant fibrous histiocytoma, rhabdomyosarcoma liposarcoma, and osteogenic sarcoma. [1],[9],[10] Osseous differentiation of the stroma contributes to the histologic complexity of these tumors and correlate with malignant phyllodes tumor (high grade).

   Conclusion Top

Malignant phyllodes tumor of the breast can be diagnosed by FNAC. It is very important to acknowledge the morphologic variants of sarcomatous stroma and to recognize the cytologic features of such rare tumors that help in planning the most appropriate treatment. It is also important to follow up the patients postoperatively for long periods for recurrence and metastases.

   References Top

1.Vera-Alvarez J, Marigil-Gσmez M, Abascal-Agorreta M, Garcνa-Prats MD, Lσpez-Lσpez JI, Pιrez-Ruiz J. Malignant phyllodes tumor with pleomorphic liposarcomatous stroma diagnosed by fine needle aspiration cytology: a case report. Acta Cytol 2002;46:50-6.  Back to cited text no. 1
2.Moffat CJ, Puinder SE, Dixon AR, Elston CW, Blamey RW, Ellis IO. Phyllodes tumors of the breast: a clinicopathological review of thirty-two cases. Histopathology 1995;27:205-18.  Back to cited text no. 2
3.Millar EK, Beretov J, Marr P, Sarris M, Clarke RA, Kearsley JH, et al. Malignant phyllodes tumors of the breast display increased stromal p53 protein expression. Histopathology 1999;34:491-6.  Back to cited text no. 3
4.Bernstein L, Deapen D, Ross RK. The descriptive epidemiology of malignant cystosarcoma phyllodes tumors of the breast. Cancer 1993;71:3020-4.  Back to cited text no. 4
5.Tse GM, Ma TK, Pang LM, Cheung H. Fine needle aspiration cytology features of mammary phyllodes tumors. Acta Cytol 2002;46:855-63.  Back to cited text no. 5
6.Rao CR, Narasimhamurthy NK, Jaganathan K, Mukherjee G, Hazarika D. Cystosarcoma phyllodes. Diagnosis by fine needle aspiration cytology. Acta Cytol 1992;36:203-7.  Back to cited text no. 6
7.Ward RM, Ewan HL. Cystosarcoma phyllodes. A clinicopathological study of 26 cases. Cancer 1986;58:2282-9.  Back to cited text no. 7
8.Powell CM, Rosen PP. Adipose differentiation in cystosarcoma phyllodes. A study of 14 cases. Am J Surg Pathol 1994;18:720-7.  Back to cited text no. 8
9.Barnes L, Pietruszka M. Rhabdomyosarcoma arising within a cystosarcoma phyllodes. Case report and review of the literature. Am J Surg Pathol 1978;2:423-9.  Back to cited text no. 9
10.Silver SA, Tavassoli FA. Osteosarcomatous differentiation in phyllodes tumor. Am J Surg Pathol 1999;23:815-21.  Back to cited text no. 10

Correspondence Address:
Jayashree Krishnamurthy
Department of Pathology, VIMS, Bellary
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0970-9371.73305

Rights and Permissions


  [Figure 1], [Figure 2], [Figure 3], [Figure 4]

This article has been cited by
1 Phyllodes tumor with a benign heterologous osseous component: a diagnostic challenge
Lene Gaarsmand Christensen,Tina Di Caterino,Maj-Lis Talman
APMIS. 2019; 127(6): 484
[Pubmed] | [DOI]
2 Risk of Local Recurrence of Benign and Borderline Phyllodes Tumors: A Danish Population-Based Retrospective Study
Kaveh Borhani-Khomani,Maj-Lis Møller Talman,Niels Kroman,Tove Filtenborg Tvedskov
Annals of Surgical Oncology. 2016; 23(5): 1543
[Pubmed] | [DOI]
Ezhil Arasi Nagamuthu, Anunayi Jeshtadi, Archana Boddu, Lavanya Motrapu
Journal of Evidence Based Medicine and Healthcare. 2016; 3(50): 2518
[Pubmed] | [DOI]


    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Email Alert *
    Add to My List *
* Registration required (free)  

    Case Report
    Article Figures

 Article Access Statistics
    PDF Downloaded113    
    Comments [Add]    
    Cited by others 3    

Recommend this journal