# Abnormal expression of LCA and CD43 in SCLC: a rare case report and brief literature review

## TL;DR

This case report describes a rare instance of small cell lung cancer with unusual LCA and CD43 expression, highlighting the importance of careful diagnosis.

## Contribution

The paper presents a rare case of SCLC with abnormal LCA and CD43 expression, emphasizing diagnostic challenges.

## Key findings

- The tumor cells were positive for LCA and CD43, which are uncommon in SCLC.
- The case highlights the risk of misdiagnosis due to atypical immunohistochemical profiles.
- Further studies are needed to understand the significance of LCA and CD43 in SCLC.

## Abstract

To present an unusual case of abnormal LCA expression and CD43 in SCLC and to review the reported literature to avoid potential diagnostic pitfalls.

A 73-year-old male patient suffered from persistent back pain for more than one month. MRI revealed a compression fracture of the L1-L5 vertebra. A CT scan revealed multiple nodules and masses at the left root of the neck, lung hilum and mediastinum, and multiple areas of bony destruction of the ribs. Histology of the tumor revealed that small and round cells were arranged in nests with areas of necrosis. The tumor cells were round to ovoid with scant cytoplasm and indistinct cell borders. The nuclear chromatin was finely granular, and the nucleoli were absent or inconspicuous. Immunohistochemically, the tumor cells were positive for cytokeratin, TTF-1, POU2F3, LCA, and CD43.

This report highlights a potential diagnostic pitfall in the diagnosis of SCLC, urges pathologists to exercise caution in cases of LCA and CD43 positivity and illustrates the need for further immunohistochemical studies to avoid misdiagnosis.