Rapid Evolution of a Squamous Cell Carcinoma In Situ to Locally Invasive With Perineural Involvement

November 2020 | Volume 19 | Issue 11 | Case Reports | 1110 | Copyright © November 2020


Published online October 16, 2020

Margit Juhasz MD MSc,a Joel L. Cohen MDa,b

aUniversity of California, Irvine, Department of Dermatology, Irvine, CA
bAboutSkin Dermatology and DermSurgery, Greenwood Village, CO

Abstract
We present a case of rapidly progressing squamous cell carcinoma in situ (SCCis) with progression to aggressive SCC. An elderly gentleman with multiple medical comorbidities presented with a left zygomatic tumor initially diagnosed as SCCis with adnexal extension on histology. After a period of approximately 10 weeks, the patient underwent Mohs micrographic surgery (MMS) with evidence that the tumor was now consistent with a well-differentiated SCC, with perineural involvement. MMS was stopped after two stages and the patient was sent to head and neck surgical oncology for further evaluation and management.

It has been reported in the literature that 3–5% of SCCis will progress to invasive SCC; although the inciting event to cause such progression is unknown, it is thought that mutations in key oncogenes or tumor suppressor genes such as TP53 may play a role. In addition, as many as 31% of SCCis may have a component of invasive SCC that is missed on initial histology due to sampling bias. This case reminds us that sampling bias can occur during biopsy, SCCis can rarely progress to invasive SCC, and highly aggressive SCCs may prove to be therapeutically challenging requiring a multidisciplinary approach.

J Drugs Dermatol. 2020;19(11):1110-1111. doi:10.36849/JDD.2020.5184

INTRODUCTION

Non-melanoma skin cancers (NMSCs) are one of the most common type of cancer worldwide. When diagnosed early, basal cell and squamous cell carcinomas (BCC and SCC, respectively) are easily treated with local destruction or surgical excision. However, delay in detection or treatment can result in NMSCs becoming locally destructive, invasive and even metastatic. SCC in situ (SCCis, also known as Bowen or Bowen’s disease) is a superficial form of SCC in which cancerous cells have not invaded through the full-thickness epidermis. The presence of atypical basaloid cells is associated with progression of pre-cancerous skin lesions to invasive SCC.1

There is a reported 3%–5% rate of SCCis progression to invasive SCC;2 however, occult invasion of SCCis has been reported in as many as 10% of cancers subsequently removed by surgical excision or Mohs micrographic surgery (MMS).3 Due to sampling bias, it has been reported that 31% of SCCis diagnosed on biopsy can have a component of invasive SCC which is discovered on the final pathology of the surgically excised specimen.4 In this report, we describe a case of a rapidly progressive SCCis to invasive SCC with perineural involvement resulting in a therapeutic and diagnostic conundrum.

CASE

A 91-year-old man with an extensive medical history including multiple NMSCs, colon cancer, severe heart disease requiring a pacemaker, and multiple orthopedic fractures secondary to osteoporosis presented to clinic with a biopsy-proven SCCis with adnexal extension on the left zygoma. The patient was subsequently scheduled for MMS, however suffered a hip fracture requiring admission to a rehabilitation facility for eight weeks. The patient was offered radiotherapy, however refused, and MMS was scheduled upon patient’s discharge from the rehabilitation center. The patient underwent MMS 10 weeks after initial diagnosis of the SCCis.