"Leiomyomatoid angiomatous neuroendocrine tumor" (LANT) of the pituitary reflects idiosyncratic angiogenesis in adenomas of the gonadotroph cell lineage.

Schürch, Christian; Birrer, Michèle Andrea; Estella, Isabelle; Kappeler, Andreas; Hewer, Ekkehard; Vajtai, Istvan (2013). "Leiomyomatoid angiomatous neuroendocrine tumor" (LANT) of the pituitary reflects idiosyncratic angiogenesis in adenomas of the gonadotroph cell lineage. Pathology, research and practice, 209(3), pp. 155-160. Elsevier 10.1016/j.prp.2013.01.003

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Based on a single-case observation, the descriptive label "leiomyomatoid angiomatous neuroendocrine tumor" (LANT) has been tentatively applied to what was perceived as a possible novel type of dual-lineage pituitary neoplasm with biphasic architecture. We report on two additional examples of an analogous phenomenon encountered in male patients, aged 59 years (Case 1) and 91 years (Case 2). Both tumors were intra- and suprasellar masses, measuring 5.6 cm × 4.4 cm × 3.4 cm, and 2.7 cm × 2 cm × 1.7 cm, respectively. Histologically, Case 1 was an FSH-cell adenoma interwoven by vascularized connective tissue septa that tended to exhibit incremental stages of adventitial overgrowth. The epithelial component of Case 2 corresponded to an LH-cell adenoma, and lay partitioned by a maze of paucicellular to hyalinized vascular axes. Irrespective of architectural variations, perivascular spindle cells exhibited immunopositivity for vimentin, muscular actin, and smooth muscle actin. Conversely, negative results were obtained for CD34, EMA, S100 protein, GFAP, and TTF-1. Ultrastructural study failed to reveal metaplastic cell forms involving transitional features between adenohypophyseal-epithelial and mesenchymal-contractile phenotype. We propose that LANT be regarded as a peculiar reflection of maladaptive angiogenesis in some pituitary adenomas, rather than a genuine hybrid neoplasm. While no mechanistic clue is forthcoming to account for this distinctive pattern, hemodynamic strain through direct arterial - rather than portal - supply of the adenoma's capillary bed may be one such explanatory factor. The apparent predilection of the LANT pattern for macroadenomas of the gonadotroph cell lineage remains unexplained.

Item Type:

Journal Article (Original Article)

Division/Institute:

04 Faculty of Medicine > Service Sector > Institute of Pathology > Clinical Pathology
04 Faculty of Medicine > Service Sector > Institute of Pathology
04 Faculty of Medicine > Service Sector > Institute of Pathology > Autopsy

UniBE Contributor:

Schürch, Christian; Birrer, Michèle Andrea; Estella, Isabelle; Kappeler, Andreas; Hewer, Ekkehard and Vajtai, Istvan

Subjects:

500 Science > 570 Life sciences; biology
600 Technology > 610 Medicine & health

ISSN:

0344-0338

Publisher:

Elsevier

Language:

English

Submitter:

Doris Haefelin

Date Deposited:

13 Jul 2015 09:29

Last Modified:

09 Feb 2017 13:25

Publisher DOI:

10.1016/j.prp.2013.01.003

PubMed ID:

23419690

BORIS DOI:

10.7892/boris.70202

URI:

https://boris.unibe.ch/id/eprint/70202

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