Prominent signet ring cell morphology in a pulmonary squamous cell carcinoma

Nuri Yigit,Ertugrul Celik,Ibrahim Yavan

doi:10.5146/tjpath.2015.01337

Abstract

In daily practice, signet ring cell morphology immediately brings to the mind the possibility of an adenocarcinoma at first glance. The signet ring cell appearance has been described and is well-known in a wide variety of some other neoplasms as well. Surprisingly however, neoplastic cells having the same morphology can unexpectedly be encountered in not previously well-documented tumors. Here, we present an 85-year-old man diagnosed with primary pulmonary squamous cell carcinoma and a large signet ring cell population. Examination of the lobectomy specimen and further radiological workup was consistent with stage I disease. Signet ring cell variant of squamous cell carcinoma is a very infrequent tumor and has been reported in only eight cases from skin, cervical and oral cavity biopsies as well as in one case of pulmonary acantholytic variant of squamous cell carcinoma with focal signet ring cells. To be aware of this entity is crucial for pathologists to reach the correct diagnosis, particularly in cytological samples, because of its potentially modifying effect on treatment options and patient management compared to adenocarcinomas. Our patient remained in clinical remission during the 9-month follow-up.

Highlights

The term ‘signet ring cell morphology’ describes a cell with a large intracytoplasmic vacuole, resulting in compression and eccentric displacement of the nucleus.Malignant signet ring cells are more commonly seen in the adenocarcinomas, those of gastric, colonic, pancreatic, breast, and lung origin
The presence of a dominant population of atypical signet ring cells is almost always associated with a diagnosis of an adenocarcinoma that is called “signet ring cell carcinoma”
This scenario works in most cases, pathologists should be cautious regarding the risk of overlooking the different types of tumors, very infrequently encountered, with very similar morphology

Summary

Introduction

The term ‘signet ring cell morphology’ describes a cell with a large intracytoplasmic vacuole, resulting in compression and eccentric displacement of the nucleus.Malignant signet ring cells are more commonly seen in the adenocarcinomas, those of gastric, colonic, pancreatic, breast, and lung origin. We would like to remind pathologists that atypical signet ring cells are most frequently seen in adenocarcinomas, but it is very important and crucial to know that they can unexpectedly be seen in other non-adenocarcinoma tumor types that have not been well-described . Signet ring cell variant of pulmonary squamous cell carcinoma (SCC) is an extremely uncommon neoplasm and only one such case containing focal signet ring cell alteration has been recently described so far.

Results

Conclusion