Malignant pleural effusions due to adeno-endocrine-cell carcinoma of the appendix: A case report

Background Lung adenocarcinomas present as tight clusters and three‐dimensional balls in effusion specimens. Unlike carcinomas of breast and stomach where singly lying malignant cells are seen in effusion samples, lung adenocarcinomas usually show cohesive morphology. This single‐cell pattern may also be confused with reactive mesothelial cells. We studied the frequency of pulmonary adenocarcinoma with single‐cell pattern cytomorphology in pleural effusion specimens. Materials and Methods All cases reported as either suspicious or positive for malignancy on pleural effusion cytology (PFC) over the past 1 year were retrieved. The clinical details were obtained from requisition forms. Cases with predominant single‐cell pattern, clinically suspicious of carcinoma lung were segregated. These were de‐stained and immunocytochemistry (ICC) for TTF‐1 was performed. Results Of 103 cases reported as either suspicious or positive for malignancy on PFC, 29 had a predominant single‐cell pattern. Of these, 13 (44.8%) were primary lung carcinoma. The rest were metastasis from ovary (5; 17.2%), breast (2; 6.9%), stomach (2; 6.9%), lymphoma (1; 3.5%), and Ewing's sarcoma (1; 3.5%). Five (17.2%) were those with unknown primary. All cases of lung carcinoma were positive for TTF‐1 ICC. Conclusion Single‐cell pattern of pulmonary adenocarcinoma is commoner than popularly believed. This pattern may be difficult to differentiate from carcinoma cells of other sites as well as from reactive mesothelial cells. A high degree of suspicion is therefore needed to perform relevant ICC to clinch the correct diagnosis.

Section: Discussionmentioning

confidence: 99%

“Single‐cell pattern” of adenocarcinoma cells in effusion cytology: Morphologic challenges of lung cancer

Guleria

Barwad

Malik

et al. 2020

“…21 In contrast, there are very few reports describing the cytologic features of carcinoid tumors in effusions. [22][23][24] Lozowski et al 22 report the cytologic findings in various diagnostic samples, including 15 body fluid specimens, from 18 patients with carcinoid tumors from various sites. The authors comment that the exfoliative smears rarely showed the cytologic pattern that is most characteristic of carcinoid tumors in FNA preparations.…”

Section: Discussionmentioning

confidence: 99%

“…22 Two additional case reports describe the cytologic features of a peritoneal fluid involved by metastatic goblet cell carcinoid and pleural fluid involved by an ''adeno-endocrine-cell carcinoma.'' 23,24 The pleural fluid findings of the latter were initially interpreted as representing small cell carcinoma due to the presence of smallsized cells with scant cytoplasm, high nuclear to cytoplasmic ratio, coarse hyperchromasia, nuclear overlap, and molding.…”

Section: Discussionmentioning

confidence: 99%

Cytology of metastatic thymic well‐differentiated neuroendocrine carcinoma (thymic carcinoid) in pleural fluid: Report of a case

Cameron

Alsharif

McKeon

et al. 2008

Thymic carcinoid tumors (well-differentiated neuroendocrine carcinomas) are uncommon anterior mediastinal neoplasms. These tumors are frequently accompanied by other endocrinopathies as part of a multiple endocrine neoplasia type I syndrome (MEN type I) and by paraneoplastic Cushing's syndrome and have a poor prognosis. We present the case of a 24-year-old man who presented for follow-up of thymic carcinoid with extensive bony metastases. He had recently completed radiotherapy to lesions involving his skull and mandible. An ultrasound-guided left-sided diagnostic and therapeutic thoracentesis was performed yielding 1 l of cloudy yellow fluid. The cytologic fluid preparations consisted of large "cannonballs" and atypical cell groups with salt and pepper nuclear chromatin. A panel of immunohistochemical stains were performed on the cell block material, and the atypical cells were positive for cytokeratin, synaptophysin, and chromogranin, but not for TTF1. These findings were consistent with metastatic well-differentiated neuroendocrine carcinoma (carcinoid tumor). This is the first reported case of a carcinoid tumor manifesting as large, spherical, smoothly contoured cell aggregates ("cannonballs") in a pleural fluid. Despite its rarity, a metastatic carcinoid tumor should be considered when "cannonballs" are found in effusions.

“…There have been several reports of metastatic GCC in effusion, and a few types of cells have been described. A common characteristic is signet‐ring cells with abundant cytoplasm and displaced nuclei.…”

Section: Discussionmentioning

confidence: 99%

“…Because of its malignant potential, it is classified as an appendiceal cancer in the 4th, and most recent, edition of the WHO classification . Confusingly, however, GCC with atypical morphology is classified as a mixed adenoneuroendocrine carcinoma (MANEC), which is referred to as adenocarcinoma ex GCC by Tang et al There are some reports of pleural effusion due to GCC, but the cytological features of GCC and MANEC have yet to be discussed.…”

mentioning

confidence: 99%

Cytological findings of appendiceal mixed adenoneuroendocrine carcinoma in pleural effusion: Morphological changes evident after metastasis

Tonooka

Oda

Hayashi

et al. 2014

Goblet cell carcinoid (GCC) of the appendix is now regarded as a malignant tumor, and mixed adenoneuroendocrine carcinoma (MANEC) is a carcinoma progressing from GCC. We describe a man initially diagnosed with GCC of the appendix who died 4 years after diagnosis. Pleural fluid due to metastasis was noted in the terminal phase. Histological findings of the initial tumor indicated that cells with signet-ring morphology were predominant, but the cytological morphology of the fluid was more atypical, making it difficult to diagnose as metastatic GCC by cellular morphology alone. The cells in the pleural fluid were immunopositive for synaptophysin, which was compatible with GCC, but p53 and ki67 staining indicated that the metastatic tumor was more aggressive. These findings suggested a final diagnosis of poorly differentiated adenocarcinoma-type MANEC, which we define as a tumor with typical GCC characteristics and foci that cannot be distinguished from a poorly differentiated adenocarcinoma. This case, which we believe is reported here for the first time, indicates the cytological features of GCC cells may change at metastatic sites to be more atypical and aggressive as the tumor progresses, and these changes should be considered in diagnosis.