Lethal midline granuloma (LMG) is an historical term for a condition in which necrotic and highly destructive lesions develop progressively in the middle of the face, principally the nose and
palate. Many cases presented with ulcerations in or perforations of the palate.
LMG was thought to be a manifestation of three
or four
different diseases: the well-characterized disease of
granulomatosis with polyangiitis, the ill-defined disorders of polymorphic reticulosis or mid-line malignant reticulosis, and an incompletely defined form of
non-Hodgkin lymphoma. Subsequent studies found that the cells infiltrating the midline tissues in cases of lethal midline granuloma that were not clearly diagnosed as granulomatosis with polyangiitis were: a) infected by the
Epstein–Barr virus and b) consisted of malignant
lymphocytes, usually
NK cells or, rarely,
cytotoxic T cells.
The disease is therefore now regarded as a NK/T cell malignancy, is grouped with other
Epstein–Barr virus–associated lymphoproliferative diseases and is classified by the
World Health Organization (2017 update) as a manifestation of the well-defined disease,
extranodal NK/T-cell lymphoma, nasal type (ENKTCL-NT).
ENKTCL-NT is a rare type of
lymphoma that commonly involves the nasal cavity, oral cavity, and/or
pharynx but less commonly can also involve the eye,
larynx
The larynx (), commonly called the voice box, is an organ in the top of the neck involved in breathing, producing sound and protecting the trachea against food aspiration. The opening of larynx into pharynx known as the laryngeal inlet is about ...
, lung,
gastrointestinal tract
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organ (biology), organs of the digestive syste ...
, skin, and various other tissues.
Patients presenting with highly localized midline facial disease fit the historical definition of lethal midline granuloma. These cases, unlike other cases ENKTCL-NT that have more widespread disease, often show no or relatively little progression of their disease over long periods of time.
Since cases of LMG that were manifestations of granulomatosis with polyangiitis, a vascular inflammatory but not malignant disease, the term lethal midline granuloma is considered confusing and obsolete.
References
External links
Lymphoma
Lymphoid-related cutaneous conditions
Epstein–Barr virus–associated diseases
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