Primary squamous cell cancer (SqCC) of the breast is a rather rare disease. These tumors are known to be quite aggressive in nature and are usually found to be treatment-resistant. Currently, there is no standard treatment guideline for the management of primary SqCC of the breast. In this case report, we present a case of primary SqCC of the breast in 60-year old postmenopausal women presenting as pigmented lesion over the right breast (no lump). Initial skin biopsy (core) done by dermatologist revealed squamous cell cancer in situ (Bowen’s disease); however surgical resection of the lesion and subsequent histopathological examination revealed primary SqCC (no secondary sites were found elsewhere in the body).

1. ONCOLOGY | CASE REPORT
PRIMARY SQUAMOUS CELL CANCER OF BREAST: A
CASE REPORT
Ketan Vagholkar∗,1, Shashwat Singh∗, Meenal Mapari∗ and Dhairya Chitalia∗
∗Department of Surgery, D.Y.Patil University school of Medicine, Navi Mumbai-400706. MS. India.
ABSTRACT Primary squamous cell cancer (SqCC) of the breast is a rather rare disease. These tumors are known to be
quite aggressive in nature and are usually found to be treatment-resistant. Currently, there is no standard treatment
guideline for the management of primary SqCC of the breast. In this case report, we present a case of primary SqCC of
the breast in 60-year old postmenopausal women presenting as pigmented lesion over the right breast (no lump). Initial
skin biopsy (core) done by dermatologist revealed squamous cell cancer in situ (Bowen’s disease); however surgical
resection of the lesion and subsequent histopathological examination revealed primary SqCC (no secondary sites were
found elsewhere in the body).
KEYWORDS Primary squamous cell carcinoma; breast cancer; biopsy; Bowen’s disease
Introduction
Primary squamous cell carcinoma (SqCC) usually arise in the
sun-exposed parts of the body; report of primary SqCC arising in
the breast tissue is very rare (the incidence rate being 0.04-0.1%
of all breast cancers) [1-3].
Theoretically, these types of tumors develop due to squa-
mous metaplasia of cancerous ductal cells [3-5]. Cutaneous
malignancy of the breast usually involves the nipple-areola com-
plex in the form of Paget’s disease. These tumours are usually
described as being highly aggressive, negative for hormone re-
ceptors and refractory to treatment (poor prognosis) [4-6].
Here we present a case of cutaneous SqCC of the breast which
was initially diagnosed as Bowen’s disease but later confirmed
as invasive SqCC after histopathological examination of the
resected specimen. In this case report, the diagnostic red flags of
this extremely rare condition are highlighted.
Copyright © 2020 by the Bulgarian Association of Young Surgeons
DOI:10.5455/ijsm.Primary-Squamous-Cell-cancer-Breast
First Received: July 26, 2020
Accepted: August 10, 2020
Associate Editor: Ivan Inkov (BG);
1
Annapurna Niwas, 229 Ghantali Road. Thane 400602. MS. India; E mail:
kvagholkar@yahoo.com; Mobile: 9821341290
Case report
A 60-year-old lady was referred to the surgical facility of a ter-
tiary care hospital in western India for excision of a pigmented
lesion over the right breast (Figure 1).
The patient gave a history of the lesion being present for
five years. However, there was a rapid increase in size over the
last one year. Initially, the patient sought consultation from a
dermatologist who performed a biopsy of the lesion.
The diagnosis of Bowen’s disease (squamous cell carcinoma
in situ) was made as there was no invasive component seen in
the slide (Figure 2). There was no history of any arsenic exposure
or exposure to any pesticides. There was no vaginal infection
with HPV (confirmed by gynaecologist of the same hospital).
The patient was referred to the surgery department for surgi-
cal excision. Physical examination of the right breast revealed
pigmented cutaneous lesion. The lesion was 3 cm in diameter,
circular in shape situated medial to the right nipple. There was
no lump in the affected breast. Examination of ipsilateral ax-
illa, contralateral breast and axilla were within normal limits.
Examination of other organ systems was also within normal
limits.
Preoperative blood reports (complete blood count, blood
sugar, both fasting and postprandial, creatinine and blood urea
and nitrogen) were within normal limits.
No radiological investigations (CT scan/MRI scan/PET CT)
were done for the lesion.
The patient underwent a wide local resection of the lesion.
The incision was marked to ensure a 5 mm margin all around
Ketan Vagholkar et al./ International Journal of Surgery and Medicine (2020) 6(4):32-35

2. Picture 1: Clinical photograph of the lesion.
Picture 2: Squamous cell carcinoma in situ. (Bowen’s disease)
Full thickness dysplasia of epidermis marked by black arrow.
(H&E 10X)
the lesion. (Figure 3A). The lesion was resected with 1.5 cm
depth into the subcutaneous tissues (Figure 3B and 3C). The
incision was closed primarily. (Figure 4) The specimen was
sent for histopathological examination which revealed the lesion
to be of basaloid variant of invasive squamous cell carcinoma
(Figure 5A and 5B). The margins of the specimen were all free
of tumour. Immunohistochemistry (IHC) markers for P40 were
positive confirming SqCC (Figure 6). Postoperative recovery
was uneventful. The patient has been following up for three
months with no recurrence.
No chemotherapy or radiotherapy was offered to the patient.
Discussion
Literature review revealed that primary SqCC of the breast is
quite rare, and it usually follows an aggressive course. Com-
pared to primary SqCC of the breast, metastasis to breast tissue
from other primary sites of cancer like lungs, skin, stomach,
or skin, are quite common. [7] Postmenopausal women are
more commonly found to have primary SqCC of breast tissue
[7, 9]; however, there are several reports of the same occurring
in younger women [7, 8]. Reported cases of primary SqCC of
breast revealed the usual size of the lesion to be as large as 8 cm;
Picture 3a: Incision marked with a margin of 5 mm all around.
Picture 3b: Resected specimen.
Picture 3c: Adequate resection extending into the subcutaneous
tissues.
Ketan Vagholkar et al./ International Journal of Surgery and Medicine (2020) 6(4):32-35

3. Picture 4: After healing of the incision.
usually larger than breast adenocarcinoma [6].
There are usually no specific mammographic or ultrasound
features for primary SqCC of the breast. The biopsy is the only
confirmatory investigation. HP examination revealed the pres-
ence of sheets of malignant squamous cells within between in-
tercellular bridges and keratin deposits. In our case, the lesion
was positive for IHC marker P40, which was confirmatory for
SqCC. There was no axillary (neither ipsilateral nor contralateral)
lymph nodal involvement in our patient. Similar to our findings,
the literature review also revealed that 70% of the patients with
breast SqCC do not have axillary lymph node involvement [9].
Moreover, there are number of criteria for the diagnosis of
primary SqCC of the breast; these are the tumor should not arise
from the surface of the skin of the breast or that of the nipple, 90%
of the tumor cells are squamous in nature, thorough exclusion
of the tumor as being secondary in nature metastasizing from
other extramammary sites, and absence of neoplastic ductal or
mesenchymal elements [1-5].
In the present case, the patient satisfied all the above men-
tioned four criteria.
Due to the rarity of this tumor, the treatment strategy for
primary SqCC is not yet established. Currently, employed treat-
ment strategies are taken from treatment strategies for manage-
ment of invasive ductal and lobular breast cancers. In our case,
the patient was managed with total surgical resection of the
lesion; no adjuvant chemotherapy or radiotherapy was given as
it was a circumscribed lesion which was completely removed.
However, a literature search revealed that there are published
reports of primary SqCC where patients received multifaceted
therapy involving surgical resection of lesions, chemotherapy,
radiotherapy and also anti-estrogen drugs. But the efficacy of
this type of multidimensional treatment strategy is not yet estab-
lished, especially due to the rare occurrence of the tumor. Some
of the SqCC tumors of the breast are found to be radiosensitive,
and some are not [10].
Again chemotherapeutic drugs usually used for management
of invasive ductal carcinoma of the breast might not be effective
for SqCC of the breast. Aparicio I and his colleagues published
a study through compilation and analysis of data on patients
diagnosed with SqCC of the breast from 1979 to 2006 [6]. They
found 11 such cases out of a total of 5771 breast cancer cases.
Picture 5a: Squamous cell carcinoma: Dysplastic stratified squa-
mous epithelium invading the underlying dermis in the form of
lobules, nests and cords. Upper dermis shows pigment inconti-
nence. Deep dermis and subcutaneous tissues are unremarkable.
(H&E 40X)
Picture 5b: Individual tumour cells are basaloid with round
to polygonal shape, pleomorphic and hyperchromatic nuclei.
Tumour nests show peripheral palisading. (H&E 400X).
Ketan Vagholkar et al./ International Journal of Surgery and Medicine (2020) 6(4):32-35

4. Picture 6: Immunohistochemistry showing nuclear positivity in
tumour cells for P40 (100X).
They found the tumors were aggressive in nature and usually
were treatment refractory. Moreover, they noted that there was
no survival benefit for SqCC patients receiving neoadjuvant
or adjuvant chemotherapy compared to patients who did not
receive chemotherapy.
Also, the tumors being hormone receptor-negative, hormone
blockade might be quite ineffective.
Prognosis of primary SqCC of the breast is not clear. Some of
the published reports claim the outcome to be similar to those
of poorly differentiated breast cancer (low overall survival rate).
Aparicio, I and his colleagues found the mean disease-free sur-
vival interval to be 92 months [6]. In another case report on
primary SqCC of breast cancer, the patient was doing well after
surgical resection of the tumour alone at 36 months after surgery.
Similarly, another case reported by Carbone S and her colleagues
where 51 year old women diagnosed with primary SqCC tumor
of breast was managed with breast conserving surgery (lumpec-
tomy) and adjuvant chemotherapy and radiotherapy [11].
In the case presented the patient did not present with breast
lump rather only with pigmented lesion over right breast (that
is why she consulted dermatologist at first). Initial biopsy report
was that of Squamous cell carcinoma in situ (Bowen’s disease).
However, surgical removal of the lesion revealed the actual
nature of the tumor (primary SqCC of the breast).
Conclusion
Hence before coming to any conclusion regarding pigmented
lesions of the breast, surgical resection and subsequent biopsy of
the lesion is mandatory for confirmation of diagnosis and also
to avoid the wrong diagnosis.
Conflict of interest
There are no conflicts of interest to declare by any of the authors
of this study.
Acknowledgement
I would like to thank the Dean of D.Y.Patil University School of
Medicine for allowing me to publish the case report.
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