European Annals of Otorhinolaryngology, Head and Neck diseases (2013) 130, 95—98

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CASE REPORT

Ectopic pyriform sinus parathyroid adenoma

N. Guevaraa,∗, B. Agopiana, D. Benisvyb, S. Lassallec, J. Santini a,L. Castilloa

a Institut universitaire de la face et du cou, groupement de coopération Sanitaire, centre hospitalier universitaire de Nice,centre Antoine-Lacassagne, 31, avenue de Valombrose, 06107 Nice cedex 2, Franceb Service de médecine nucléaire, centre Antoine-Lacassagne, 33, avenue de Valombrose, 06189 Nice cedex 2, Francec Laboratoire de pathologie clinique et expérimental, hôpital Pasteur, CHU de Nice, 30, avenue de la Voie-Romaine, 06000 Nice,France

KEYWORDSAdenoma;Parathyroid;Pyriform sinus;Ectopic

SummaryObjective: To describe the diagnosis and treatment of ectopic pyriform sinus parathyroid ade-noma.Material and methods: A 44-year-old woman presented with persistent primary hyperparathy-roidism after previous failed cervical exploratory surgery.Results: Diagnosis of ectopic pyriform sinus parathyroid adenoma was suggested by computedtomography and technetium-99 m sestamibi scintigraphy (99mTc-MIBI SPECT/CT). A submucosaltumor was identified under laryngoscopy and resected by endoscopic CO2 laser. Histopathology

confirmed the diagnosis of parathyroid adenoma.Conclusions: Ectopic pyriform sinus locations are rare in parathyroid adenoma. 99mTc-MIBISPECT/CT facilitates diagnosis, especially in case of previous failed neck exploration. Endo-scopic CO2 laser resection is the treatment of choice.© 2012 Elsevier Masson SAS. All rights reserved.

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Introduction

Ectopic parathyroid adenoma is a significant cause of post-surgical persistent primary hyperparathyroidism (PHPT) [1].

Pre-operative assessment generally allows diagnosis ofthe ectopic gland, but there remains a non-negligible riskof false negatives, as not all parathyroid lesions take up

sestamibi in the same way [2].

False positives on this examination are much rarer, oftendue to associated nodular thyroid pathology [3].

∗ Corresponding author. Tel.: +33 04 92 03 17 68.E-mail address: guevara.n@chu-nice.fr (N. Guevara).

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1879-7296/$ – see front matter © 2012 Elsevier Masson SAS. All rights redoi:10.1016/j.anorl.2012.04.008

A pyriform sinus location is quite exceptional; there haseen only one report of management by endoscopic CO2

aser [4].We report the case of a woman presenting with ectopic

denoma of the pyriform sinus, not diagnosed on initialcintigraphy, and treated, after failure of classic neck explo-ation, by endoscopic CO2 laser.

ase report

44-year-old woman was referred for surgical managementf PHPT. Two successive assessments found hypercalcemiand inadequate parathormonemia (ionized calcium and PTH:

served.

96

Figure 1 Weighted subtraction images after planar scintig-raphy (99mTc/99mTc-MIBI). Hyperfixation at right parathyroid P4(black arrow). NB: moderate fixation could be discerned onretrospective re-reading in the inferior part of the left sub-mandibular fovea (white arrow), doubtless corresponding to thepyriform sinus adenoma.

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.48 mmol/L; 56 pg/L (< 38.8), and 1.36 mmol/L; 122.7 ng/L< 51), respectively. Cervical ultrasound found a non-suspectulti-micronodular thyroid with no increase in parathy-

oid volume. 99mTc-MIBI parathyroid scintigraphy suggestedight retrothyroid hyperfunctional parathyroid more or lessn position P4 (Fig. 1).

Cervicotomy with right parathyroid exploration wasssociated to resection of the right P IV, which showedacroscopically increased volume. Histology found slight

odular hyperplasia.Postoperative biological analysis found persistent PHPT:

onized calcium, 1.40 mmol/L; PTH, 93 pg/mL (< 38.8).ormonal assessment for associated multiple endocrine neo-lasia was normal.

Parathyroid scintigraphy was again performed, coupledo CT (99mTc-MIBI SPECT/CT), 2 months post-surgically. Theestamibi fixation facing the right fossa was unchanged;estamibi fixation as seen at the left pyriform sinus was sug-estive of a hyperfunctional ectopic parathyroid or of andenopathy (Fig. 2).

Flexible endoscopy visualized a submucosal tumefactionf the left pyriform sinus (Fig. 3).

Direct suspension laryngoscopy was performed, withO2 laser lesion resection. Macroscopic examination of thepecimen found a 1.8 × 1 × 1-cm nodular lesion of tissu-ar consistency. Anatomopathologic examination suggesteddenoma, despite the absence of an identifiable residual

ing of normal parathyroid tissue.

Postoperatively, blood values returned to normal: ionizedalcium, 1.15 mmol/L; PTH, 10.1 ng/L; at 6 months’ follow-p, there was no recurrence.

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N. Guevara et al.

iscussion

HPT involving ectopic pyriform sinus adenoma has beenarely reported, and often entails difficulties of diagnosisnd treatment [4,5].

In the present case, initial scintigraphy was false-positiveor right retrothyroid adenoma, showing a subtraction imagef sestamibi fixation with right supralobular projection.cintigraphy generally shows excellent specificity, with thealse-positive risk basically limited to associated nodularhyroid pathology [6], as in the present case. Image fusionoupling single-photon emission CT to conventional CT scanSPECT/CT) easily detects such false positives. It also greatlynhances diagnostic sensitivity to ectopic adenoma [7] andeems indispensable in patients having already undergoneurgical exploration. It is indeed sometimes recommendeds a systematic first-line examination [8].

Thus, retrospectively, on the second scintigraphic explo-ation, the right supralobular projection image could benterpreted as showing micronodular lesions with greaterptake of 99mTc-MIBI than of technetium alone. As theltrasound and peroperative aspects of these micronodularesions were in no way suspect, no surgical treatment waspplied.

It is noteworthy that the first scintigraphic examinationlso failed to diagnose ectopic adenoma. The sensitivityf planar scintigraphy is around 87% to 94% [2,6]. Eveno, on retrospective re-reading of the first results, slightlyeinforced fixation projecting under and inward of the leftubmaxillary gland could be discerned on the planar images.his represented fixation of the ectopic adenoma, which,owever, was overlooked due to the low degree of fixation,ts unexpected location and the apparently more typicalcintigraphic right P4 image.

Cervical ultrasound is indispensable: it also can revealncreased parathyroid volume and enables precise morpho-ogic assessment of the thyroid gland. Thus, associatedS-SPECT-CT performs better than the alternative imagingechniques, raising sensitivity to more than 90% and thusnabling even more precise selection of candidates for min-mally invasive surgery [5,9].

Embryologically the P3 and P4 parathyroids are of endo-ermic origin, deriving respectively from the 3rd and 4thranchial clefts. Two types of ectopia have been reported:ongenital, resulting from pathologic embryonic migration,nd acquired, resulting from secondary migration underravitational force. To these may be added embryonicefects in pharyngeal sac migration, a rare pathology inhich vestigial parathyroid tissue may subsist in the phar-nx. It is rare for adenoma to develop on such vestigialissue; very few cases have previously been reported [10],nd the present case is an addition to these.

Endoscopic CO2 laser resection has, to the best of ournowledge, been described in only one previous report4]. The technical characteristics of CO2 laser enable pre-ise non-hemorrhagic surgery and thus complete excisiononserving the gland. This intra-cavity technique avoidedurther cervicotomy, thus minimizing surgery time and mor-

idity.

Ectopic pyriform sinus parathyroid adenoma 97

Figure 2 Tomoscintigraphy coupled to CT (99mTc-MIBI SPECT/CT). Tissue image with moderate Tc-MIBI fixation localized in theleft pyriform sinus.

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igure 3 Flexible endoscopy. Submucosal mass in the superiornd posterior part of the left pyriform sinus.

onclusions

ctopic pyriform sinus locations are rare in parathyroid ade-oma. 99mTc-MIBI SPECT/CT facilitates diagnosis, especiallyn case of previous failed neck exploration. Endoscopic CO2

aser resection is the treatment of choice.

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N. Guevara et al.

isclosure of interest

he authors declare that they have no conflicts of interestoncerning this article.

eferences

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