Cytological, histological, and immunohistochemical findings of pulmonary carcinomas with basaloid features

Abstract

Pulmonary basaloid carcinoma (BC), a variant of large cell, nonsmall cell carcinoma (NSCC), and basaloid squamous cell carcinoma (BSQCC) can show features similar to small cell carcinoma (SCC) and large cell neuroendocrine carcinoma (LCNEC). Distinction from SCC, especially on FNA, is therapeutically relevant. We describe cytological, histological, and immunohistochemical features of BC and BSQCC. Numerous cytologic features were documented in cytologic preparations. Similar features and architecture were evaluated in the resections. Immunohistochemical results were recorded. Histologically confirmed BC (n = 3) and BSQCC (n = 3) were included. Five FNAs of SCC, (four with histologic follow-up) were studied for comparison of cytological, histological, and immunohistochemical findings. In cytologic preparations of BC/BSQCC, cells were arranged mostly as tightly cohesive clusters (n = 4) or singly and in clusters (n = 2) with a predominance of clusters. Cytologic features of BC and BSQCC were similar: palisading (n = 6), crush artifact (n = 6), hyperchromasia (n = 5), focal nuclear molding (n = 6; very rare in 2/6), nucleoli, usually pinpoint (n = 3), scant cytoplasm (n = 6), necrosis (n = 5), apoptosis (n = 4), squamous differentiation (n = 1). BSQCC tended to have occasional larger cells, including keratinizing cells in one case. Histologic sections (n = 6) showed neuroendocrine features, including organoid arrangements, nests, and palisading. BC and BSQCC show overlapping features with SCC and LCNEC in cytological and histological specimens. Unlike SCCs, BC/BSQCC lack prominent nuclear molding, show tightly cohesive cell clusters, and demonstrate palisading. However, immunostains were the very helpful and probably necessary to accurately diagnosing BC/BSQCC, which show the immunostaining pattern of p63 (+), HMWCK (+), and TTF-1 (-).

The variable morphological spectrum of penile basaloid carcinomas: differential diagnosis, prognostic factors and outcome report in 27 cases classified as classic and mixed variants

“…They are morphologically similar to basaloid carcinomas described in other anogenital and non-genital sites (anus, cervix, vulva, head and neck, lung and esophagus) [2][3][4][5][6][7][8][9][10][11][12][13]. They comprise about 5-10% of penile squamous cell carcinomas (SCC), are frequently associated with HPV genotype 16 [14][15][16], are positive for p16 by immunohistochemistry [17] and have an aggressive clinical behavior with a high-rate of vascular invasion and inguinal lymph node metastasis [18].…”

Cytological findings of monophasic synovial sarcoma presenting as a lung mass: report of a case and review of the literature

“…These cases could be diagnostically challenging since these patients are often older and have the demographic features overlapping with non‐small‐cell carcinoma. In the lungs, the differential diagnoses for monophasic synovial sarcoma include low‐grade neuroendocrine tumor, basaloid squamous‐cell carcinoma, solitary fibrous tumor, leiomyoma, inflammatory myofibroblastic tumor, and malignant peripheral nerve sheath tumor . A comprehensive immunohistochemical panel showing negativity for neuroendocrine markers (synaptophysin and chromogranin); squamous cell markers (p63 and p40); solitary fibrous tumor markers (CD34 and STAT6); smooth muscle markers (SMA and desmin); and inflammatory myofibroblastic tumor markers (ALK, SMA, and prominent inflammatory infiltrates) can help rule out these entities.…”

Value of Thyroid Transcription Factor-1 Immunostaining in Tumor Diagnosis

“…In a review of 47 published studies on the expression of TTF-1 in squamous cell carcinomas of the lung, 23 reported positivity in 3% to 38% of the cases investigated, 42,43,45,[52][53][54][55][65][66][67][68]71,73,82,86,87,97,[109][110][111][112][113][114] whereas all of the cases in the remaining 24 investigations were negative for this marker. 20,26,35,36,44,46,47,56,63,70,85,94,100,[115][116][117][118][119][120][121][122][123][124][125] Because of the lack of adequate documentation in the vast majority of these studies, it is not possible to accurately determine all of the factors that may have played a role in the reported results. However, in a recent investigation in which an...…”