1. A CASE OF PRIMARY EXTRASKELETAL MYXOID CHONDROSARCOMA OF THE BREAST: A RECHERCHÉ ENTITY
Anurag Sharma1; Shivani Sharma1; Ram K. Kajla2; Azad Singh1; Gauraw K. Saurav1; Kamakhya Gogoi1;Lata Kini1
1Department of Pathology and Laboratory Medicine, CORE Diagnostics Pvt Ltd, Gurgaon, India; 2Department of Surgery, Prince Bijay Singh Memorial Hospital, Bikaner, India.
BACKGROUND
RESULTS
Primary chondrosarcoma of breast is rare and only 20 cases have been reported in English literature. Of the 20 cases, there was only one case of primary extraskeletal myxoid chondrosarcoma (EMC). We report a case of primary EMC of the breast in a 45-year-old woman.
Microscopic Features
The microscopic evaluation revealed a malignant neoplasm with a prominent nodular growth pattern. The tumor cells were arranged in anastomosing cords and strands. Individual tumor cells showed mild to moderate pleomorphism, hyperchromatic nuclei, prominent nucleoli, and moderate to scant eosinophilic cytoplasm and were embedded in an abundant myxoid, basophilic matrix. Necrosis, hemorrhage, and brisk mitotic activity were noted. No malignant epithelial element was seen. The benign breast acini and ductules were present in between the above-mentioned nodules; no periacinar/ductular condensation of stroma was observed (Figure 1 to Figure 3). Lymphovascular invasion was not observed. Eighteen axillary lymph nodes examined were negative for tumor. A battery of Immunohistochemical stains, including mesenchymal, epithelial, and mammary lineage- associated markers were performed to type the tumor and ascertain the histogenesis of the tumor. The tumor cells depicted immunoexpression for vimentin, S-100 protein, neuron specific enolase (NSE), CD99, and synaptophysin (SYN) in variable degrees (multifocal to diffuse) and intensities (moderate to strong), while the epithelial markers (pancytokeratin [panCK], epithelial membrane antigen, high molecular weight cytokeratin, and cytokeratin 5/6), CD34, myoepithelial markers (smooth muscle actin and p63) and mammary lineage-associated markers (GATA3, mammaglobin, and gross cystic disease fluid protein-15 [GCDFP-15]) were negative in the tumor (Figures 4 to 8). The Ki-67 labelling index was 50%. A fluorescence in situ hybridization (FISH) was performed to detect a rearrangement of the EWSR1 locus, using the LSI EWSR1dual-color, break-apart probe according to the manufacturer’s recommendations. No rearrangement involving the EWSR1 locus was detected (Figure 9). Prognostic markers, including estrogen and progesterone receptors, Her-2/neu, isocitrate dehydrogenase, and ERG were negative. A whole body imaging by PET-CT scan was within normal limit.
CASE REPORT
Clinical History
A 45-years-old female presented with a left breast mass for 1 month duration. The mass was not associated with pain, nipple discharge, or other constitutional symptoms. Local examination failed to reveal tenderness, edema, cutaneous changes (ulceration or nodularity), or axillary lymphadenopathy. Systemic physical examination was within normal limits. Personal and family history was not significant for any malignancy. Mammogram showed a fairly circumscribed mass with spicules of regular to irregular calcifications. Core needle biopsy from the breast mass showed a myxoid soft tissue tumor with chondrosarcomatous areas; interspersed benign breast acini and ducts were present. Based on the morphologic attributes, a metaplastic carcinoma, malignant phyllodes tumor with heterologous elements, myoepithelial carcinoma, extraskeletal myxoid chondrosarcoma, and metastatic myxoid soft tissue sarcoma were brought into the differential diagnostic consideration. Subsequently, a modified radical mastectomy was performed. The pathologic features are described below.
Materials and Methods
The specimen was fixed in 10% neutral buffered formalin. The sections were routinely processed and the slides were stained with Hematoxylin and eosin.
Gross Pathology
The modified radical mastectomy measured 28.0 x 18.0 x 6.0 cm with a 15.0 x 7.0 cm portion of grossly unremarkable tan skin. Nipple and areolar complex measured 3.0 x 3.0 cm and was grossly unremarkable. On sectioning, a 6.0 x 5.0 x 4.0 cm tan-white to
tan-gray, partly hemorrhagic, and partly cystic tumor was present in the central area of the breast; ivory white areas were seen interspersed with tan areas. The tumor was 4.0 cm from the deep/posterior resection margin, 2.0 cm from the overlying skin, 2.5 cm from the superior margin, 2.0 cm from the inferior margin, 4.5 cm from lateral margin, and 9.0 cm from the medial margin. Multiple tan, ovoid, and rubbery axillary lymph nodes were identified, which ranged from 0.4 cm to 1.5 cm in maximum dimension.
Fig. 2 Tumor cells in cords and nests (200X)
Fig. 1 Nodular growth pattern
(40X)
Fig. 3 Tumor cells in myxoid matrix (400X)
Fig. 6 S100 Positivity
(200X)
Fig. 4 NSE Positivity
(200X)
Fig. 5 SYN Positivity
(200X)
Fig. 7 CD99 Positivity
(200X)
Fig. 8 GCDFP 15
(200X)
Fig. 9 No Rearrangement of EWSR1 locus
REFERENCES
Lucas DR, Stenman G: Extraskeletal myxoid chondrosarcoma. Fletcher CD, Bridge JA, Hogendoorn PW, Mertens F, editors. World Health Organization Classification of Tumor, Pathology and Genetics of Tumors of Soft Tissue and Bone. Lyon, France, International Agency for Research on Cancer. 2013, pp 223e224.
Benini S, Cocchi S, Gamberi G, Magagnoli G, Vogel D, Ghinelli C, et al. Diagnostic utility of molecular investigation in extraskeletal myxoid chondrosarcoma. J Mol Diagn. 2014; 16(3):
Lubana SS, Bashir T,Tuli SS, Kemeny MM, Heimann DM. Breast Metastasis of Extraskeletal Myxoid Chondrosarcoma: A Case Report. Am J Case Rep. 2015; 16:
Agaram NP, Zhang L, Sung YS, Singer S, Antonescu CR. Extraskeletal Myxoid Chondrosarcoma with non-EWSR1-NR4A3 Variant Fusions Correlate with Rhabdoid Phenotype and High Grade Morphology. Hum Pathol. 2014; 45(5): 1084–91..
Farahat A, Magdy N, Elaffandi A. Primary myxoid chondrosarcoma of the breast. Ann R Coll Surg Engl. 2014; 96(1):112E-411E.
CONCLUSIONS
In conclusion, primary EMC of breast is an extremely rare entity and should be included in the differential diagnosis, while dealing with myxoid lesions of the breast. An expeditious diagnosis of EMC of the breast would allow the surgeon to effectuate a breast conservative surgery contrary to more radical approaches taken in cases of other primary malignant mammary neoplasms.