Tympanomastoid cholesterol granuloma: radiological and intraoperative findings of blood source connection

Abstract

The hypothesis that the close contiguity between the cholesterol granulomas and some rich blood sources provided the trigger to the aggressive nature of tympanomastoid cholesterol granulomas has been recently reported. To corroborate this new etiopathogenetic theory we retrospectively reviewed a series of 14 patients with primary middle ear and mastoid cholesterol granulomas and investigated the temporal bone marrow invasion and its hematopoietic potentialities and a possible cholesterol granulomas contiguity with relevant vascular structures such as the carotid artery, sigmoid jugular system, mastoid or dural vein. Eight cases did not show radiological sign of bone marrow invasion or hematopoietic potentialities visible in MRI. Besides no intraoperative vascular connections that could explain an initial bleeding source were found. Cholesterol granulomas bone marrow invasion was present in six patients. A bone marrow hematopoietic potentiality was showed in four of these patients, whereas, an evident anatomical contiguity of the cholesterol granuloma with some important temporal bone vascular structures was visible in five cases. Analysis of cardiovascular risk factors showed that four patients presented one or more of the risk factors analysed.

Tympanomastoid cholesterol granulomas: Immunohistochemical evaluation of angiogenesis

“…who were referred to surgery at the Sensory Organs Department of the Sapienza University of Rome in the period between January 2000 and March 2016. Two patients with CGs recently treated by surgery have been added to the total number of CG patients reported in the previously published paper . Seven patients were male and nine female, ranging in age from 18 to 82 years (average age, 41.2 years).…”

“…A review of all preoperative images (computed tomography [CT] and magnetic resonance imaging [MRI] studies) was performed in our patients. The inclusion criteria adopted for imaging evaluation of the CGs in this study were the same used in the previously published study: 1) Evidence of high signal intensity on T1‐ and T2‐weighted images or high signal intensity on fluid attenuated inversion recovery (FLAIR) MRI and low signal intensity on diffusion‐weighted MRI was usually observed in CGs. 2) Visible bone erosion and CGs invasion of the mastoid or temporal bone marrow (CT and MRI).…”

“…However, the studies of Pfister et al and Iannella et al were limited in that they were deductive studies based on radiological and intraoperative findings of CGs, without pathological or immunohistochemical data able to corroborate the investigated hypothesis.…”

“…In recent years, some authors have postulated that in most CGs, whether in the petrous apex or mastoid compartments, growth is initiated and sustained by a pathological connection with an abundant blood source within the temporal bone or the adjacent cranial base, leading to the growth of new vessels and cell proliferation …”

“…In the exposed marrow theory, exceptionally vigorous pneumatization invades and partially replaces the hypervascular marrow normally resident in the nonpneumatized apex. This exuberant pneumatization leads to a breakdown in the partition between the mucosal envelope and the blood‐rich marrow resulting in a proclivity for chronic seepage …”