Malignant phyllodes tumor in an 11-year-old girl with fatal clinical outcome. A case report

Introduction

Phyllodes tumor is a rare fibroepithelial tumor accounting for 0.3 to 1% of all breast neoplasms [1]. It’s name was first coined by Muller in 1838 as “cystosarcoma phyllodes” due to its stroma having leaf like projections into cystic spaces and due to its fleshy consistency [2]. However, in 1981, WHO renamed it as phyllodes tumor and this has gained worldwide acceptance. According to WHO criteria, phyllodes tumor is divided into three broad histological subgroups based on tumor margins, stromal cellularity, mitotic rate and pleomorphism. These are the benign, borderline and malignant subtypes [3]. Histologically it is characterized by both epithelial and stromal cells, with relatively greater stromal proliferation as compared to a fibroadenoma together with atypical cells, necrosis and hemorrhage.

Phyllodes tumor usually affects women between 35 and 54 years of age and hence is rare amongst adolescents and the elderly [4]. A number of case series have been published of malignant phyllodes in postpubertal adolescents, but there are only 5 cases of phyllodes tumor reported in premenarchal children, 3 of which were benign [5–7] and 2 malignant [8,9]. Therefore, to the best of our knowledge, we report the third case of malignant phyllodes tumor in an 11-year-old girl with lung, liver and bone metastases.

Case report

An 11-year-old girl, known case of phyllodes tumor, who presented to us with a right breast lump suggesting recurrence of phyllodes tumor and was admitted at our hospital for wide local excision of the recurrent lesion. According to the patient’s mother, she noticed a lump in the right breast 1 year back, while she was changing her daughter’s clothes. The lesion did not cause any symptoms but it rapidly increased in size. Mastectomy was done in an outside hospital and specimen was sent to our lab for histopathology which showed a malignant phyllodes tumor measuring 14 × 12.5 × 3.5 cm. The deep margin was (Figs 1 and 2) involved by tumor. Local recurrence of the tumor occurred within one month. Imaging studies were done in an outside hospital. On the basis of these investigations, a wide location excision was performed at our institution. Histopathology revealed a4.5 × 3 × 3 cm recurrent malignant phyllodes tumor. All margins were free of tumor. Histopathology showed a highly cellular lesion composed of spindle shaped cells having pleomorphic hyperchromatic elongated nuclei. Interspersed between these were plumps with vesicular nuclei having prominent nucleoli. Rare epithelial elements noted. Upto 51 mitoses/10HPFs and foci of necrosis were seen (Fig. 3). Postoperatively the patient remained stable and was discharged uneventfully. The patient presented 2 years later in clinic with complaints of dyspnea, chest pain and a large left chest wall mass. There was no other evidence of metastatic disease. CT chest showed a large soft tissue density mass involving upper mid zone of the left lung. Mass was necrotic in appearance with patchy enhancement. It measured 14.1 × 10.7 cm in craniocaudal and transverse extent, bulging into the mediastinum medially and causing encasement of the left pulmonary artery, left main bronchus and the upper lobe bronchus with surrounding pneumonitis. Mediastinal extension was positive. FNAC was done which showed poorly differentiated neoplastic cells. The patient was referred to a cardiothoracic surgeon who declared that the mass was inoperable. The patient was then admitted at another hospital and treated symptomatically. No chemoradiation was given. One year later patient died of disease due to wide spread metastasis to bone and liver.

Discussion

Phyllodes tumor usually presents as a rapidly growing painless breast lump, being firm, round, mobile, well-defined and macrolobulated [3]. A study conducted by Khurshid et al. [10] at Aga Khan University Hospital (AKUH), Karachi, Pakistan determined the frequency of phyllodes tumor (PT) in adolescent girls and young women (less than and equal to 25 years of age). It showed that only 11% of the total phyllodes tumor cases reported in the course of 16 years were below the defined age group with an equal prevalence of benign, borderline and malignant subtypes and the average age of presentation being 19.1 years, 21.9 years and 19.7 years respectively [10]. Another study conducted in Eastern Nigeria by Nzegwu et al. showed that the mean age of presentation of phyllodes tumour was 24 years with a standard deviation of 7 years, giving an average age range of 17–31 years. The masses ranged in size from 5 cm to 25 cm [11]. Hence only a few cases of phyllodes tumor in children have been reported in the literature [9,12–15]. To the best of our knowledge, this is the third case of malignant phyllodes tumor in a premenarchal girl (Table 1). It is often hard to differentiate it from a fibroadenoma on a clinical or radiological basis, hence a tissue diagnosis is preferable to investigative procedures in patients suspected of having phyllodes tumor. According to Chu et al. in a series of 106 patients with phyllodes tumor, 71.7% had a preoperative diagnosis of fibroadenoma [16]. The 5 year survival rates for benign, borderline and malignant tumors have been reported by Reinfuss et al. to be 95.7%, 73.7% and 63.1% respectively [17]. Metastasis is seen in only 10% of all phyllodes tumors with the most common sites being lungs, bone and liver [18]. Hematogenous dissemination is more frequently seen as compared to lymphatogenous metastasis being 20% and 10% respectively [19]. Poor prognostic factors include greater than 10 mitotic figures per high power fields, infiltrating margins, severe atypia, stromal overgrowth, stromal component other than fibromyxoid and tumor necrosis [20]. Malignant phyllodes tumor in our patient behaved more aggressively than other two pre-menarchal patients who were free of disease at 3 years of follow up (Table 1). Local recurrence after simple excision is seen in 21%, 46% and 65% of the benign, borderline and malignant tumors respectively and this incidence significantly decreases after wide-local excision to 8%, 29% and 36% respectively [1]. Breast-conserving surgery versus mastectomy for removal of phyllodes tumor has remained a bone of contention.

In conclusion, we report a malignant phyllodes tumor in an 11-year-old girl, which recurred twice. The patient died of disease 3 years after initial surgical resection due to wide spread metastases. Although its mean age of presentation is between 35 and 54 years of age, it should always be considered as one of the differentials in both pre and post menarchal girls presenting with a rapidly growing painless breast lump. The possibility of its malignant potential should never be ruled out.