Otolaryngology - Head & Neck Surgery Supplement - 2020 Official Program Abstracts - P200

P200
Otolaryngology-Head and Neck Surgery 163(1S)
Presentation schedule is subject to change. The Official Program Abstracts supplement does not reflect changes made after August 10, 2020.
A Rare Case of Locally Aggressive Desmoid
Fibromatosis Presenting as a Neck Mass
Lindsay C. Boven, MD (Presenter); Abhijit Gundale;
Nestor Dela Cruz, MD; Hugu H. Cuellar-Saenz, MD;
Amol Takalkar, MD; Cherie-Ann O. Nathan, MD
Objectives: Fibromatosis is a rare entity, representing 0.03%
of neoplasms, with 15% occurring in the head and neck. No
clear management guidelines exist because of the rarity of
these tumors. It is important to be aware of cases and the treatment modalities used to guide future planning.
Methods: We report a case of desmoid fibromatosis presenting as a right neck mass infiltrating the internal jugular vein
and sternocleidomastoid muscle (SCM).
Results: A 25-year-old African American man presented
with a painful rapidly growing right level 2 neck mass, firm
and minimally mobile on examination. Fine-needle aspiration
showed benign spindle cells. Computed tomography with
contrast revealed a 2- × 3-cm mass with nondistinct borders
invading the SCM and abutting the right carotid artery and
internal jugular vein. Magnetic resonance imaging showed a
T1 intermediate intensity and T2 low-intensity mass invading
the carotid sheath. No concerning fluorodeoxyglucose avidity
was seen on positron emission tomography. During surgical
exploration, the mass involved levels 2 and 3. It infiltrated the
internal jugular vein and surrounding SCM, which were both
sacrificed. Cranial nerves XI and XII were adherent to the
mass but dissected off. Histopathology confirmed desmoid
fibromatosis with positive margins. Immunohistochemistry
was positive for beta-catenin, α-smooth muscle actin, and
CD163. Ki67 had less than 1% proliferation index. Although
radiation (RT) was offered, given the patient's young age and
paucity in the literature of adjuvant RT, the patient elected for
observation with serial imaging.
Conclusions: Locally aggressive desmoid fibromatosis frequently involves adjacent structures. As in this case, it is difficult to obtain negative surgical margins and sacrifice
cranial nerves in young patients. Consideration of this tumor
in the differential with early diagnosis may lead to better
outcomes.

Head and Neck

Recurrent Neck Mass: A Case Report
Dylan Erwin (Presenter); David W. Lesko; Jay Ferrell, MD
Objectives: To discuss the diagnosis and management of a
rare branchial anomaly and provide a thorough literature
review of the topic. To describe the appearance of fourth
branchial anomaly on computed tomography scan and direct
observation.
Methods: Fourth branchial cleft anomalies are an exceptionally rare cause of recurrent neck mass in pediatric and
adult patients. In this report, we present a case of an infected
fourth branchial cleft cyst in a 20-year-old woman. This case
demonstrates the diagnostic challenges of these anomalies and
keys to their successful management. A focused literature
review highlighting the history surrounding these lesions is
also provided. The 20-year-old female presented in early 2018

with a 2-year history of recurrent left neck abscesses and subsequent treatment with antibiotics and steroids.
Results: After undergoing repeated incision and drainage
procedures, the patient underwent definitive management
with direct laryngoscopy, ablation of left pyriform sinus tract,
left hemithyroidectomy, and excision of the branchial anomaly without evidence of recurrence.
Conclusions: In addition to the diagnostic challenges and
management of this rare pathology, this case report highlights
the unique anatomical relationship between fourth branchial
anomalies and the pyriform fossa as well as the superior and
recurrent laryngeal nerves.
Resolving the Transcriptomic Heterogeneity
of Fibroblasts in the Head and Neck
Squamous Cell Carcinoma Tumor
Microenvironment
Cornelius H.L. Kurten, MD (Presenter); Aditi Kulkarni, MS;
Anthony Cillo, PhD; Stephan Lang, MD; Umamaheswar
Duvvuri, MD, PhD; Dario A.A. Vignali, PhD; Lazar
Vujanovic, PhD; Robert L. Ferris, MD, PhD
Objectives: In this study, we aim to use the novel, powerful
technology of single-cell RNA sequencing (scRNAseq) to
investigate the previously understudied, but important, fibroblasts, a cell subset implicated in limiting the efficacy in
HNSCC immunotherapy.
Methods: Nineteen tumor specimens and peripheral blood
leukocytes (PBLs) from untreated patients were freshly processed. Cell suspensions were sorted into CD45+ and CD45-
cells. 10× Genomics 3′ single-cell libraries were generated and
sequenced. After aggregation and normalization (CellRanger),
scanpy was used for the bioinformatic analyses of this highdimensional data set. Uniform manifold approximation and
projection (UMAP) clustering was performed to visualize the
data.
Results: Analyzing 136,947 single cells with 1036 median
genes, 30 different cell clusters were identified, of which
21 clusters were formed by immune cells whereas CD45-
nonimmune cells formed 9 clusters. A total of 4725 nonvascular stromal cells were further characterized by subclustering.
Cell type allocation was performed based on the highest
expressed genes and differentially expressed hallmark gene
sets. We delineated pericytes, cancer-associated fibroblasts
(CAFs), normal fibroblasts, and elastic fibroblasts. For elastic
fibroblasts-not previously described in HNSCC scRNAseq
studies-identification was corroborated by expression of tropoelastin, fibrillin-1, and microfibril associated protein 4.
Further, substantial heterogeneity could be appreciated among
CAFs, with some patient-specific clustering as well as variable expression of effector-molecules (metalloproteinases).
Conclusions: Extracting transcriptomic profiles from single cells using scRNAseq allows the detailed characteri-
zation of fibroblasts, including the identification of rare
subsets as well as the resolution of interpatient and intrapatient heterogeneity.

Otolaryngology - Head & Neck Surgery Supplement - 2020 Official Program Abstracts

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