2019 Research Forum

Applicant & Principal Investigator: Sundeep Grandhe MD R2 Faculty Sponsor: Saman N. Ratnayake MD

A Rare Case of Stage IV Basaloid Squamous Cell Cancer with Intrapulmonary and Brain Metastases

Sundeep Grandhe MD R2, Tushar Bajaj MD R1, Hanh Duong MS III, Saman N. Ratnayake MD

INTRODUCTION Metastatic Basaloid Squamous Cell Carcinoma (BSCC) is a lethal, high grade variant of squamous cell carcinoma which is extremely rare in the oral cavity but common in the oropharynx. We present one case of metastatic BSCC arising in hypopharynx with both pulmonary and brain metastases. PURPOSE A 42-year-old Male smoker presented with a one-week history of headache; however, six months prior endorsed increasing throat pain and swelling of the left neck. Oral examination identified a 2 centimeter by 2-centimeter ulceroproliferative growth with indurated margins on the lower aspect of the hypopharynx. Laryngoscopy identified a large tumor obstructing the supraglottic larynx. Triple endoscopy demonstrated a large tumor that was ulcerative within the base of the tongue. Incisional biopsy was performed at the base of the tongue and histopathology revealed tumor cells with a basaloid appearance, hyperchromatic nuclei with scant cytoplasm arranged in a lobular configuration amongst a background of mitotic figures consistent with a diagnosis of invasive basaloid squamous cell carcinoma of the base of the tongue. CT of the neck soft tissue with contrast demonstrated bilateral cervical level II and level III necrotic adenopathy likely metastatic and CT of the Chest with contrast demonstrated innumerable bilateral pulmonary nodules measuring up to I cm in diameter with mediastinal and right hilar adenopathy concerning for metastatic disease. Repeat CT chest with contrast after chemoradiation demonstrated progression of the metastatic disease with increase in both number and size of the interpulmonary metastatic nodules and mediastinal lymphadenopathy. CT of the brain with contrast demonstrated small enhancing lesion in the central brainstem atypical for metastasis. After extensive discussion, patient opted for treatment with Pembrolizumab based on the KEYNOTE-055 study. DISCUSSION Basaloid squamous cell carcinoma (BSCC) is an extremely rare variant of squamous cell carcinoma with a reported frequency of less than 1% of all squamous cell cancers [l]. It may also present like sec with a painless irregular mass which may or may not ulcerative [2,3,4,5], and frequently with metastasis of cervical lymph nodes due to rich lymphatic accessibility [6,7]. Our patient followed this presentation, coming into the emergency department with an enlarging tender neck mass.It was discovered at that time, he already had bilateral cervical level II and III necrotic adenopathy that were likely due to metastasis . BSCC is more aggressive and will more often have distant metastasis instead of recurring locally [8]. Our patient continued to have metastasis after treatment to the lungs and brain, which rarely has been reported with BSCC. CONCLUSION The diagnosis of basaloid squamous cell carcinoma in the setting of intrapulmonary and brain metastases is an extremely rare, high grade bimorphic aggressive variant of conventional SCC that needs to be histopathologically differentiated from other tumors containing basaloid component. Given its high mortality rate and aggressive clinical course, once the diagnosis is made, the treatment should be planned given the considerations.

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