Discussion:
Malignant lymphomas represent the 3rd most frequent
histological subtype of head and neck cancers (12%) after squamous cell
carcinoma (46%) and thyroid carcinoma (33%).
Extranodal involvement represents 23% of NHML and 1-4% of HML of head
and neck (2).
Four localisations are the most affected: the Waldeyer’s ring, the
sinuses and the nasal cavities, the oral cavity and the salivary glands
(3).
Waldeyer’s ring, as it is a lymphoid structure, is the site of the most
affected by head and neck extra nodal malignant lymphomas (4–8)
1) NHML of the larynx:
Primary laryngeal malignant lymphomas are rare and mainly NHML. They
predominantly arise from the supraglottic region (containing follicular
lymphoid tissue). A meta-analysis published by Kim et al, reported 57
cases of laryngeal NHML (1). They occur preferentially in elderly men.
Clinically they most often manifest as dysphonia, dysphagia, and stridor
with or without general signs (9). The diagnosis is confirmed by a
biopsy. According to the World Health Organization’s classification for
NHMLs, type B is the most common malignant cell phenotype (10, 11).
The initial assessment includes a chest, abdomen and pelvic scan
cervico-thoraco-abdominal CT and a cervical Magnetic resonance imaging,
a bone marrow biopsy and a serum LDH test. The 18-Fluoro-deoxyglucose
positron emission computed tomography (18 FDG TEP) is currently
recommended (12). Radiotherapy is the main treatment for indolent
early-stage NHML (stage I, II) at a total dose of 24 GY in 12 fractions.
It must be combined with a chemotherapy in case of presence of poor
prognosis factors. As for aggressive NHML, treatment is based on
chemotherapy: R-CHOP regimen (rituximab, cyclophosphamide, doxorubicin,
vincristine, and prednisolone) followed by consolidating radiotherapy
depending on tumor response (13,14). The prognosis is similar to lymph
node NHML. Ten years overall survival at is 50 - 60% (11)
2) HML of the larynx:
Primary extra nodal HML remains extremely rare and even exceptional
(1-4%) (2) .To our knowledge no case of a laryngeal HML has been
reported in the literature. Therefore, this case represents the first
one described. The clinical presentation is not specific and very
heterogeneous depending on the anatomical localization. The diagnosis is
confirmed by an histological and immunoisthochemical analysis (5). The
monoclonal antibodies panel used includes CD15 (Leu M1), CD20 (L-26),
CD30 (Ber H2), CD45 (LCA), CD45RO (UCHL-1), latent membrane protein type
1 (LMP-1 ; CS1-4) of Epstein-Barr virus (EBV) and polyclonal CD3 and
fascin (4,5). The most common subtype is classical mixed cellularity
lymphoma (2,4). However, Quinones-Avila et al (5) suggested that the
classical nodular-sclerosis and lymphocyte-rich Hodgkin
Lymphoma subtypes are more common. This could be explained by the fact
that in previous studies lymphomas diagnosis was only based on the
histomorphological characteristics and old malignant lymphomas
classification systems were used.
Head and neck HML treatment consists in ABVD chemotherapy regimen
followed by a radiotherapy at a total dose of 25 to 40 Gy, targeting the
Waldeyer ring and the involved cervical lymphnodes fields (8).
This treatment provides excellent disease long-term local control with
similar results to those reported in cases of lymph node HML. According
to the results of a cohort of 34 patients, head and neck extra nodal HML
treated with ABVD or MOPP regimens chemotherapy (mechlorethamine,
vincristine, procarbazine, and prednisone) followed by radiotherapy at a
total dose of 39.6 Gy, in the MD Anderson Cancer Center at the
University of Texas between 1967 and 2007, the 10-year disease-free
survival rate was 71% (2).