Pigmented Squamous Cell Carcinoma In Situ: Report of a New Case and Review of the Literature

Abstract

Pigmented squamous cell carcinoma in situ (PSCCIS) is very rare, being clinically described as a pigmented lesion with histological characteristics of an in-situ carcinoma presenting pigmentation within neoplastic cells. A 50-year-old Afro-descendant man came for clinical evaluation of a painful black and red lesion located on the right aspect of the oropharyngeal isthmus. After incisional biopsy, the resulting sample was described as a pigmented squamous cell carcinoma in situ, a diagnosis further confirmed by immunohistochemical analysis. Treatment consisted in total excision of the lesion, and no recurrence was observed after a 30-month follow-up. Clinicians and pathologists should be aware of PSCCIS as a differential diagnosis of melanoma, a lesion which significantly increases the morbidity and mortality rates among these patients. Key words:Pigmented squamous cell carcinoma in situ; oropharyngeal mucosa; immunohistochemistry.

Clinicopathological and immunohistochemical characteristics of pigmented oral squamous cell carcinoma

“…The most common location of POSCC in this study was the tongue (72%), which is consistent with previous findings ( 13 – 22 ) and in line with conventional OSCC. Similar to 18 reported cases ( 13 – 22 ), 23 tumors (92%) were diagnosed as pathological T1-T2 stage. In total, 23 of 25 cases (92%) were low-invasive type POSCC.…”

“…Histological analysis revealed that 28% of cases, showing early invasion patterns, shared some similarities with the characteristics of pigmented carcinoma in situ (22). In previous studies, there have been four cases of OSCC in situ with the symbiosis of melanocytes (13,15,21,22), two of which showed white discoloration on the lesion (15,21). Our study found pigmentation in leukoplakia associated with the tumor in 7 cases (28%).…”

“…Our study found that pigments were interspersed in neoplastic cells from the epithelial surface to the basal layer. Histological analysis revealed that 28% of cases, showing early invasion patterns, shared some similarities with the characteristics of pigmented carcinoma in situ ( 22 ). In previous studies, there have been four cases of OSCC in situ with the symbiosis of melanocytes ( 13 , 15 , 21 , 22 ), two of which showed white discoloration on the lesion ( 15 , 21 ).…”

“…POSCC is a rare variant of SCC that is histologically similar to typical SCC but with the presence of non-neoplastic melanocytes within the lesion ( 20 , 22 ). Pigmentation in POSCC is not always macroscopically visible and may be detected only microscopically ( 18 , 19 ).…”

“…Although pigmentation, commonly found in the oral mucosa, represents various clinical patterns ranging from physiological alterations to oral manifestations of systemic diseases and malignancies, pigmented oral squamous cell carcinoma (POSCC) is a rare and underrecognized pathological variant of OSCC. To the best of our knowledge, only 18 cases have been reported in the English literature (13)(14)(15)(16)(17)(18)(19)(20)(21)(22). Owing to the lack of a large case series, the clinical characteristics, treatment outcomes, and prognosis of POSCC remain unclear.…”