PMC8631727_01
Echocardiographic image: solid neoplasm floating in the left ventricle outflow chamber, connected to the anterolateral papillary muscle of the left ventricle and characterized by homogeneous density, large base implant, and regular margins.
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F1
The echocardiographic images (Figure 1) revealed an ovoid mass, adherent to the anterolateral papillary muscle and characterized by a similar echogenicity to the myocardial tissue with a mobile offshoot located in the outflow tract; the radiologists confirmed a suspicion of a single expansionary lesion through CT scan of the chest with contrast.
The area between the tumor and the normal myocardium is characterized by a mixed inflammatory infiltrate composed of polymorphonuclear leukocytes, lymphocytes, monocytes, and plasma cells (Col. Hem-Eos, original magnification x40: A,B).
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F2
A surgical exploration revealed the presence of a polypoid, non-encapsulated, and lobulated neoplasm measuring 4 x 0.3 x 0.2 cm (Figure 2), with hard elastic consistency, smooth external surface, and foci of mucoid degeneration (Figure 3) surgically removed by exeresis through transaortic access, obtaining samples for the histological, histochemical, and immunohistochemical analysis.
Gross view: lobulated and polypoid tumor measuring in cm 4 x 0.3 x 0.2, of whitish color, and of elastic consistency. Compact tissue with focal mucoid degeneration was observed to cut.
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F3
A surgical exploration revealed the presence of a polypoid, non-encapsulated, and lobulated neoplasm measuring 4 x 0.3 x 0.2 cm (Figure 2), with hard elastic consistency, smooth external surface, and foci of mucoid degeneration (Figure 3) surgically removed by exeresis through transaortic access, obtaining samples for the histological, histochemical, and immunohistochemical analysis.
Microscopic view; the neoformation, localized predominantly in the subendocardium, has a polypoid aspect (A,B), and it consists of monomorphic spindle cells, without atypia, dense proliferation, arranged both in parallel bundles (B) and storiform pattern (C). Coagulative necrosis was observed in the central part of the tumor (Col. Hem-Eos, original magnification x10: A,B; x40: C,D).
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F4
The histological exams, performed with hematoxylin-eosin, Masson's trichrome, Alcian blue PAS, and Weigert and Van-Gieson stain, allowed observing the microscopic structure of the neoplastic mass, consisting of spindle monomorphic cells, arranged in parallel bundles and a storiform pattern (Figure 4), and conspicuous inflammatory components with a population of lymphocytes and granulocytes.
Neoplastic spindle cells infiltrate the small intramural coronary vessels extrinsically, with subsequent flow obstruction and ischemic necrosis of the tributary myocardium (Col Hem-Eos: A,B; actin: C,D; original magnification x10: A,D; x40: B,C).
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F5
The spindle cells infiltrated the small intramural coronary vessels with consequent obstruction and ischemic necrosis of the tributary myocardium (Figure 5).
Spindle cells showing positivity for the actin:muscle specific (A,B) and vimentin stain (C,D) (original magnification x10: A; x40: C,D; x100: B).
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F6
Spindle cells showed positivity for anti-vimentin, anti-ASMA, anti-muscle specific actin (Figure 6), and anti-ALK (Figure 7); the inflammatory component resulted positive for anti-CD3, anti-CD 8, anti-CD20, anti-kappa, and lambda chains and anti-CD68 antibodies.
Spindle cells (col Hem-Eos: A) showing positivity for the ALK stain (B) (original magnification x10).
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F7
Spindle cells showed positivity for anti-vimentin, anti-ASMA, anti-muscle specific actin (Figure 6), and anti-ALK (Figure 7); the inflammatory component resulted positive for anti-CD3, anti-CD 8, anti-CD20, anti-kappa, and lambda chains and anti-CD68 antibodies.