Squamous cell carcinoma, a rare variant of primary breast carcinoma: a case report

Breast cancer is the most common malignancy occurring worldwide in females but primary squamous cell carcinoma represents a very rare variant of breast carcinoma, accounting for less than 0.1%. Mostly it is grayish-white in colour with an ill-defined cut surface and has cystic areas of foci of necrosis macroscopically. Squamous elements in these neoplasms can range from well to poorly differentiated. The majority was moderately differentiated and showed cystic degeneration correlating with the macroscopic appearance.

A 45-year-old female presented to us with a painless progressive lump involving all quadrants of left breast that at presentation had involved the whole breast and was associated with foul-smelling discharge. The patient had toxic features and was taken up for toilet mastectomy. The wound was left open for a delayed closure. The histopathological report suggested triple negative squamous cell carcinoma involving the breast.

Squamous cell carcinoma is commonly seen in the skin and lung, it rarely originates in breast tissue. There are reports that it may develop within a previous benign lesion such as an epidermal cyst or chronic inflammatory lesions. It may also mimic benign breast disease resulting in inappropriate or delayed management. Clinically and radiologically it is indistinguishable from adenocarcinoma, the most common presentation being cystic lesion. Because of limited data and few case reports worldwide, management strategies have been controversial. Total mastectomy with axillary clearance is usually done. As it is locally advanced, conservative surgery is not feasible most of the time. Radiotherapy has been used in locally advanced cases, though not much useful.

Very rare incidence along with nonspecific presentation poses a major challenge in the diagnosis of primary SCC.