An HIV-positive patient may develop an inflammatory myofibroblastic tumor (IMT). The development in an IMT in a patient with AIDS is a poor prognostic sign.
Tissue source: mesenchymal
Behavior: low malignant potential with many cured by complete excision
Sites of occurrence:
(1) lung
(2) adrenal gland
(3) GI tract
(4) spinal cord
(5) head and neck
(6) other extrapulmonary sites
Histologic features:
(1) spindle cells proliferation without atypia
(2) abundant small blood vessels
(3) myxoid and collagenous matrix
(4) mixed inflammatory infiltrate
Positive immunoperoxidase stains: vimentin (strong), smooth muscle actin (weak, focal)
Negative immunoperoxidase stains: S-100
Signs associated with worse prognosis:
(1) ALK1 positive
(2) RET, ROS1, NTRK3 or PDGFRbeta mutations
(3) metastases
