phyllodes tumor of the breast accounts for 0.3%1% of all primary breast tumors and for 2.5% of all fibroepithelial tumors of the breast .
they are circumscribed biphasic fibroepithelial tumors , with classic histology showing hypercellular mesenchymal stroma and double - layered epithelium in clefts .
based on stromal cellularity , atypia , mitosis and nature of tumor margins , phyllodes tumor is classified into benign , borderline , and malignant .
coexistence of invasive carcinoma in the proximity of malignant phyllodes tumor as synchronous collision tumors and skin ulceration by malignant phyllodes tumor is extremely rare .
we report one such case in a 51-year - old female presenting as a fungating mass .
a 51-year - old female presented with a history of breast lump for past 6 months .
there was a history of rapid increase in size with pain and ulceration for 1 month .
there was no history of breast malignancy in the family . on examination , left breast showed a huge foul smelling fungating mass with absent nipple and areola , occupying almost entire left breast .
positron emission tomography scan revealed large hypermetabolic mass in the left breast and few hypermetabolic lymph nodes in the left axilla .
there was no evidence of metastasis elsewhere in the body . with the diagnosis of phyllodes tumor probably malignant with skin ulceration , mastectomy with axillary dissection
an another firm tumor measuring 2.5 cm with spiculated margin was seen at the periphery of large tumor , abutting it [ figure 1 ] .
histology of the larger tumor showed stromal predominance occupying a low power field [ figure 2 ] , increased cellularity , spindle cells with moderate atypia , and increased mitosis [ figure 3 ] of 13/10 high power field ( hpf ) .
, an epithelial tumor is seen without transition zone in between [ figure 4 ] , consists of cells in tubules and trabeculae with stromal desmoplasiar [ figure 5 ] .
a diagnosis of malignant phyllodes tumor with ulceration with coexisting invasive carcinoma of no special type was rendered .
gross specimen showing large lobulated phyllodes tumor ( gray arrow ) and a spiculated tumor at its proximity ( black arrow ) low - power view of phyllodes tumor showing stromal predominance and epithelial cleft ( h and e , 10 ) phyllodes tumor showing hypercellular stroma and increased mitosis ( arrows ) ( h and e , 40 ) phyllodes tumor merging with invasive carcinoma of no special type ( h and e , 10 ) invasive carcinoma showing tumor cells in nests and tubules ( h and e , 40 )
phyllodes tumor is a biphasic fibroepithelial tumor of the breast , accounting for 0.3%1% of all primary breast tumors and for 2.5% of all fibroepithelial tumors of the breast .
clinically , patients present with unilateral firm breast mass , not attached to skin . large tumors might stretch the skin , but ulceration is very rare ( seen in our case ) .
phyllodes tumor is classified based on stromal cellularity , stromal atypia , stromal overgrowth , mitosis and tumor margins into benign , borderline , and malignant .
any phyllodes tumor can harbor ductal carcinoma in situ or invasive carcinoma , although it is an uncommon finding .
the epithelial tumor can be seen either with or outside the phyllodes tumor , synchronously , or metachronously , in the same or distinct breast .
very rare cases of malignant phyllodes tumor with coexisting invasive carcinoma outside the phyllodes tumor in the same breast were described .
our patient had invasive carcinoma in the proximity of phyllodes tumor without a transition zone synchronously in the same breast as a collision tumor .
genetic changes with intratumoral heterogeneity have been reported , which might lead to the transformation of epithelial and mesenchymal elements , resulting in the development of phyllodes tumor and the association of breast carcinoma inside the phyllodes tumor .
the coexistence of both tumors can be made out by meticulous examination of the specimen and extensive sampling .
phyllodes tumor have homogenous surface with lobulated margins , while breast carcinoma usually has firm consistency with spiculated margins .
histologically , malignant phyllodes tumor reveal stromal overgrowth occupying more than a low - power field , hypercellularity , stromal atypia , mitosis of more than 10/10 hpf , and invasive margins
local recurrence is usual and can metastasize to lungs , liver , and bone by hematogenous spread .
it is graded based on the amount of tubule formation , nuclear atypia , and mitosis per 10 hpf .
it usually metastasize to axillary lymph nodes , and to other organs such as lungs and bone .
the behavior of the tumor and treatment depends on the higher grade of either of the tumors , mitotic activity , resected margin status , skin involvement , and metastasis .
malignant phyllodes tumor with coexisting invasive breast carcinoma in the same breast outside the phyllodes tumor is a rare occurrence .
there were two case reports of malignant phyllodes tumor ulcerating the skin with coexisting invasive breast carcinoma as collision tumor and presenting as a large fungating mass in the english literature .
early diagnosis and complete surgical removal prevent the recurrence of such tumors and improve patient outcome .
treatment of these rare cases has to be standardized with a multimodal approach , including complete surgical removal with axillary clearance , and adjuvant treatment with chemotherapy and radiotherapy as well .
 phyllodes tumor is a rare fibroepithelial biphasic tumor of the breast composed of hypercellular mesenchymal stroma and double - layered epithelial component , arranged in clefts with leaf - like projections . 
 phyllodes tumor with coincidental presence of invasive carcinoma or in situ ductal carcinoma in the same or distinct breast is a rare occurrence , documented by some reports . 
 invasive carcinoma can be seen within or outside the phyllodes tumor . 
 skin ulceration by malignant phyllodes tumor with coexisting invasive carcinoma as collision tumor is extremely rare . here , we report an extremely rare presentation of malignant phyllodes tumor as a giant fungating mass with distinct invasive carcinoma in the same breast in a 51-year - old female . 
Introduction
Case Report
Discussion
Conclusion
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