Pulmonary large cell neuroendocrine carcinoma exhibiting extensive pagetoid spread in the bronchial epithelium: A case report

Neuroendocrine carcinoma of the uterine cervix with extensive pagetoid spread pattern

There have been no reported cases of neuroendocrine carcinoma (NEC) of the cervix with pagetoid spread (Pag-S). A 44-year-old woman came to our department because of abnormal cytology that persisted immediately after a radical hysterectomy for NEC of the cervix. A mapping biopsy in a large area from the vaginal wall to the vulva revealed that synaptophysin/Ki-67-positive tumor cells were scattered within the epithelium in multiple areas, suggesting a wide Pag-S of NEC. Because tumor cells were found beyond the vaginal wall, the anterior pelvic exenteration was performed. Since we could pathologically confirm the complete resection and no distant metastases were detected, no adjuvant therapy was performed. Four years have passed since the initial treatment without any tumor recurrence. It is known that the prognosis of NEC of the cervix that invades beyond the cervix is poor; however, if there is a Pag-S pattern, a radical surgical treatment can be considered.

Pulmonary Neuroendocrine Carcinomas in Situ: Do They Exist?

INTRODUCTION

Although precursor lesions of pulmonary squamous carcinoma, adenocarcinoma, and carcinoid tumor are well known and accepted entities, precursor lesions of pulmonary neuroendocrine carcinomas, i.e., small cell lung carcinoma and large cell neuroendocrine carcinoma, have never been identified. A small body of literature documenting intraepithelial involvement in cases of pulmonary neuroendocrine carcinomas begs the question of whether the intraepithelial lesion represents de novo intraepithelial neoplasia or invasion by underlying tumour.

METHODS AND MATERIALS

The literature on cases of invasive neuroendocrine carcinomas with an intraepithelial component exhibiting a neuroendocrine immunophenotype was thoroughly and critically reviewed.

RESULTS

The authors of the publications of cases of coexisting invasive and intraepithelial neuroendocrine carcinoma generally favour invasion as the explanation for the intraepithelial component. However, in practice, it is difficult or impossible to determine the direction of migration of tumor cells when there is both an invasive and intraepithelial component. Pulmonary neuroendocrine carcinomas in situ have been produced in genetically engineered mouse models.

CONCLUSIONS

Based on the illustrations in the literature of human cases and the production of pulmonary neuroendocrine carcinomas in situ in genetically engineered mice, it seems likely that these tumours also exist in humans. However, their existence and acceptance require definitive proof. Studies should be undertaken to identify bronchial and other lung biopsies with in situ carcinoma exhibiting a neuroendocrine immunophenotype and a subsequent negative resection specimen and no follow-up evidence of invasive carcinoma. Documenting such cases would provide definitive proof for the existence pulmonary neuroendocrine carcinomas in situ in humans.

Pagetoid involvement of bronchioles by metastatic breast carcinoma

We report a case of a 36-year-old female with endobronchiolar spread of breast carcinoma in the lung. The patient had recently been diagnosed with invasive ductal breast carcinoma and imaging of the lungs revealed bilateral lung nodules. She then underwent a wedge resection of a lung nodule. The biopsy revealed a subpleural metastatic nodule of invasive ductal carcinoma with an intra-alveolar pattern of spread at its advancing edge. Several smaller foci of intra-alveolar tumor were noted as well as pagetoid spread of tumor cells along a 0.9 mm wide bronchiole. The neoplastic cells were TTF-1 negative, GATA3 positive and ER positive. This is the third reported case of pagetoid spread of metastatic breast carcinoma along the bronchial tree. This case emphasizes the importance of examining not only bronchi but also bronchioles to detect this unusual pattern of spread of metastatic breast carcinoma in lung resection specimens.