J Clin Pathol 1981;34:1155-1162

Ectopic vestigial lesions of the neck and shouldersDS SHAREEF,* R SALM

From the Department of Histopathology, Royal Postgraduate Medical School, Hammersmith Hospital,London W12 OHS

SUMMARY A series of five vestigial lesions of the shoulder and back is reported. Their derivation isdiscussed and in four cases a branchial rather than a bronchial origin is favoured. The fifth case isheld to represent skin involvement by thyroglossal duct elements.

Most heterotopic tissues in the head and neck are dueto persistent embryonic structures, especially of thebranchial and thyroglossal vestiges.' We wish toreport a series of five cases of this type from the neckand shoulders, in order to draw attention to suchunusual manifestations and to discuss their disputedhistogenesis.

Case reports

CASE 1A negro female, aged 11 months, presented with aperiodically discharging subcutaneous lump on herleft shoulder which had been present since birth.This was situated in the left supraclavicular regionoverlying the supraspinatus muscle, and wasattached to the deep fascia. Healing after excision wasuneventful.

Microscopical examinationThe subcutaneous fat contained a centrally cysticnodule, 0 5 cm across, which communicated with thepigmented epidermis by way of an epidermis-linedduct, its melanin pigmentation decreasing withincreasing depth. Around the duct there were sweatand sebaceous glands, hair follicles and smoothmuscle bundles. The central cyst, 03 x 02 cm, wasfilled with keratin squames, inflammatory exudateand scanty erythrocytes. It was preponderantlylined by ciliated pseudostratified epithelium ofrespiratory type with focal groups of goblet cells anda thick basement membrane (Fig. 1), but one per-ipheral segment was lined by keratinising non-pigmented epidermis with a prominent granularlayer (Fig. 2). The subepithelial tissues were denselyinfiltrated with lymphocytes with an occasional

*Present address: Department of Histopathology, MountVernon Hospital, Northwood, Middlesex HA6 2RN.

Accepted for publication 29 April 1981

reactive centre. The fibrous cyst wall incorporated afew small sebaceous glands below the epidermis, andelsewhere there were groups of seromucinous glands,some of which were present in the adjacent fat tissue.In one level there were also a number of smoothmuscle bundles.

CASE 2A four-year-old girl presented from birth with a sub-cutaneous cyst on her left shoulder overlying theacromial process. There had been a slight dischargefrom the lesion for a week before excision. Healingwas uneventful.

Microscopical examinationThe lumen of the cyst was filled with pus. The cystlining had a somewhat wavy outline and consistedmainly of ciliated pseudostratified epithelium ofrespiratory type with many goblet cells, demarcatedby a delicate basement membrane (Fig. 3). One smallarea was lined by epidermis with underlying smallsweat glands (Fig. 4). A narrow zone of densechronic inflammatory infiltrate was present belowboth types of epithelium, followed by a thin ring offibrous tissue with occasional smooth musclebundles. There were no mucous glands.

CASE 3A 22-year-old woman underwent an operationfor the excision of the right thyroid lobe forpresumptive colloid nodule. The subcapsular thyroidparenchyma showed posteriorly an area of fibrosiswith many small cysts containing pale mucoidmaterial.

Microscopical examinationHyaline fibrous tissue, 2 x 1-2 cm, replaced theperiphery of the thyroid lobe, with widespreadvascular proliferations which varied in size fromcapillary to sinusoidal. There were numbers of

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Fig. 1 Case 1. Corrugated cyst walllined by respiratory epithelium withdistinct basement membrane covered byinflammatory exudate. Underlyinglymphoid tissue with reactive centre, smallseromucinous gland and two small smoothmuscles left and right. Haematoxylin andeosin x 60.

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| Fig. 2 Case 1. Segment of cystF. wall lined by hyperkeratotic

epidermis with small sebaceousglands at bottom.

* Haematoxylin and eosin x 150.

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Ectopic vestigial lesions of the neck and shoulders

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excised together with an adjacent small tissue nodule,09 x O5 cm.

Microscopical examinationThe separate nodule consisted of fibrous tissue withmany incorporated large tubular and cystic spaces ofirregular outline, measuring up to 04 x 0-2 cm,some of which contained mucin. These were lined byciliated epithelium of respiratory type (Fig. 8) withvarying numbers of goblet cells. There was a patchydense subepithelial lymphocytic infiltrate, but smoothmuscle and mucous glands were absent.

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Fig. 3 Case 2. Cyst wall lined by ciliated respiratory

epithelium covered by inflammatory exudate.

Underneath a zone oflymphoid infiltrate with smooth

muscle at bottom. Haematoxylin and eosin x 600.

incorporated glandular tubules and cysts, measuringup to 06 cm across (Fig. 5). The larger cysts werelined by flattened epithelium and often containedmucin. Elsewhere the lining epithelium was of theciliated pseudostratified respiratory type withoccasional goblet cells and an inconspicuous base-ment membrane, sometimes bordered by a smoothmuscle layer with underlying seromucinous glands(Fig. 6). A single cyst was lined by thick, non-keratinising stratified epithelium with a patchilythickened basement membrane, and this was theonly cyst to show subepithelial lymphocytic infil-tration (Fig. 7). Loosely arranged smooth musclefibres were encountered along the periphery of anoccasional glandular structure, and smooth musclefibres and groups of seromucinous glands were alsodistributed haphazardly in the fibrous stroma.

CASE 4

A 26-year-old woman was admitted for hyper-parathyroidism. A parathyroid adenoma was

hyperkeratotic epdems coee by infammtor

bunle. SmAl sweat glnd at bttmHaematoxylln and eosin x 150.

,;.*W AKVW'^o+;b S.e. .. +

bundles.~~~~~~~~.mlswea ......totom

bundes.atoxal swand eosind at bottom

Shareef, Salm

Fig. 5 Case 3. Cyst wall lined by low respiratoryepithelium and adjacent thyroid tissue. Haematoxylinand eosin x 150.

CASE 5

A 17-year-old woman underwent an operation forthe excision of a longitudinal, granular, depressedarea of skin in the midline of the neck measuring5 x 0-5 cm, which had been present since birth. Thepatient was symptom free four years later.

Microscopical examinationCross-sections through the excised strip of skinconsisted of striated muscle, presumably platysmal,covered by skin. Along the excisional margins theepidermis was thin and the dermis contained sweatand sebaceous glands. More centrally the epidermiswas acanthotic and the underlying corium lackedany skin appendages. Instead, there were numbers ofshort perpendicular tubules which opened on to theskin surface (Fig. 9). These were lined by ciliatedpseudostratified epithelium of respiratory type withmany goblet cells and a delicate basement mem-

brane, surrounded by a dense chronic inflammatoryinfiltrate. Branching tubules, demarcated by thickbasement membranes (Fig. 10), penetrated thestriated muscle to a depth of 0-2 cm.

Discussion

The salient features of the five cases are listed inTable 1. All our patients were females, in contrast tothe findings of Fraga et al.2 of a male preponderanceof 5: 1, based on material from the files of the ArmedForces Institute of Pathology. As one would expectwith developmental lesions, our three superficiallysituated cases were detected at birth. The two lesionslocated in the deeper tissues were only demonstratedon microscopical examination of the excised tissues.The small shoulder cyst of case 1 had had a dis-

charging sinus, whereas the discharge of the largershoulder cyst of case 2 had been slight and of shortduration, thus suggesting that cyst size is largelydependent on the presence or absence of a patentfistula.

Microcystic lesions embedded in fibrous tissuewere noted in cases 3 and 4, the lesion of case 3 beingsituated within the substance of the thyroid lobe, andthat of case 4 adjacent to it. One of the cysts reportedby Fraga et al.2 was also present close to a thyroidlobe, but we have been unable to trace any previousreport of an intrathyroidal localisation. The linearmidline lesion of case 5 is pathognomonic of aderivation from the thyroglossal duct. The remainingfour lesions were interpreted as being of branchialrather than of bronchial origin for reasons discussedbelow.The one microscopical feature common to all five

cases was the presence of ciliated respiratoryepithelium which lined the cysts preponderantly orexclusively. Smaller areas of epidermis or stratifiedepithelium were present in cases 1, 2, and 3, theepidermis in case 1 being associated with sebaceousglands, and in case 2 with sweat glands. A patchilythickened basement membrane was noted in cases l,3, and 5, a feature also noted by Fraga et al.2 and Drutet al.3 The chronic subepithelial inflammatoryinfiltrate was dense in cases 1 and 2, which had haddischarging sinuses, but in the remaining cases suchinfiltrate was either focal or minimal. Smoothmuscles were present in cases 1, 2, and 3, and sero-mucinous glands in cases 1 and 3. Most of thesefindings are in agreement with those of previousreports; the similarities and differences are sum-marised in Tables 1 and 2.As to pathogenesis, there is general consensus that

lesions of this type are not teratomatous, because ofthe presence only of tissue elements compatible witha derivation from the primitive foregut.

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Ectopic vestigial lesions of the neck and shoulders

Table 1 Summary offive cases of ectopic vestigial lesions ofneck and shoulders

Case Sex Age at Site Size Macroscopical Respiratory Goblet Epidermis Sero- SmoothNo presentation (cm) appearance epithelium cells or mucinous muscle

(yr) stratified glandsepithelium

I F 11/12 Shoulder 0-4 Singlecyst ± + + + +2 F 4 Shoulder 4 Single cyst + + + + +3 F 22 Intrathyroidal 2-5 x 1-2 Microcystic + + + + +4 F 26 Juxtathyroidal 0-8 x 0 5 Microcystic + + - - -5 F 17 Midline of neck 5 x 0 3 Linearscar + +

Table 2 Summary ofpreviously reported subcutaneous vestigial cysts of neck and thorax

References No of Site Respiratory Goblet Stratified Sero- Smooth Cartilagecases epithelium cells epithelium mucinous muscle

glands

"2Seybold and Clagett1948 1 Presternal + + - + - +

'Fraga et al. 1971 30 26 in or near suprasternalnotch3 over scapula1 on shoulder + + - 16/30 24/30 2/30

8Constant et al. 1973 1 Suprasternal notch + + + + + -

3Drut et al. 1974 4 Suprasternal notch 4 4 - 4 4

Fig. 6 Case 3. Cyst wall lined byrespiratory epithelium. Underneath azone ofsmooth muscles and large

I .. seromucinous gland. Haematoxylin andtc eosin x 150.

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The two modes of histogenesis considered mostlikely are origins from the branchial pouches or fromthe respiratory buds. The chief protagonists thatsuch cysts represent ectopic bronchial cysts have beenFraga et al.2 These authors put forward the view thatcells from the respiratory buds are pinched off andsequestrated during early fetal development, thoughthey did admit that the location in the shoulder andscapular areas in four of their patients was difficult toexplain on this basis. Cogent arguments, however,can be advanced against the postulated bronchialderivation of such cysts.

Firstly, although two of their cases showed thepresence of sinuses leading to behind the manubrium,they were unable to demonstrate a connection withthe respiratory system. On the other hand, somebranchial cysts possess lower pedicles, and lower

Fig. 7 Case 3. Cyst lined by stratified epithelium withdistinct basement membrane and adjacent lymphoidinfiltrate. Haematoxylin and eosin x 400.

Fig. 8 Case 4. Cyst lined by ciliated respiratoryepithelium with adjacent lymphoid infiltrate.Haematoxylin and eosin x 600.

external as well as upper internal sinuses have beenfound in about one-third of all branchial cysts.4Secondly, intrathoracic bronchial cysts are notinfrequently associated with other congenital abnor-malities.5 In contrast, no other congenital lesions,including skeletal defects, have ever been recorded inassociation with the cysts under discussion.

Fraga et al.2 rejected a branchial origin for severalreasons: the presence of smooth muscle and sero-mucinous glands; the paucity of lymphoid tissue; theoccasional presence of cartilage; and their mostcommon anatomical sites in or near the suprasternalnotch.As to the presence of seromucinous glands, these

have occasionally been seen in the walls of branchialcysts.4 But whereas bronchial cysts are lined byrespiratory epithelium and possess smooth musclecoats, branchial cysts are predominantly lined bystratified epithelium and lack smooth muscle in theirwalls.

This morphological difference is usually attributedto branchial clefts being of ectoendodermal deri-vation. However, if sequestration of cells shouldoccur both early in fetal life as well as from thedeeper-that is, from the endodermal parts of thebranchial cleft membrane, then differentiation torespiratory epithelium is as likely to occur as insequestrations from the respiratory bud. Mucousglands are also likely to develop, analogous to theformation of sebaceous and sweat glands below theepidermis in cases 1 and 2, and induction of the

Ectopic vestigial lesions of the neck and shoulders

Fig. 9 Case 5. Tubular glands linedby respiratory epithelium opening on toskin surface surrounded by lymphoidinfiltrate. Haematoxylin and eosin x 60.

ig. IO CaseS.Deeper tubular glandlined by ciliatedrespiratoryepithelium with manygoblet cells and thickbasement membrane.Haematoxylin andeosin x 400.

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surrounding primitive mesenchyme to form smoothmuscle and, more rarely, of cartilage, can be readilyenvisaged.

Cysts with discharging sinuses become infected,and their florid lymphoid tissue should be regardedas a secondary reaction, as already pointed out byNicholson.6 Thus, the paucity of lymphoid tissue insome of the cysts under consideration probablyreflects the fact that they were closed cysts, and doesnot exclude a branchial derivation.

Contrary to the contention of Fraga et al.,2 theoccasional presence of cartilage is not proof of abronchial origin, for islands of cartilage have beendemonstrated in the walls of branchial cysts4 6 7hence the term "cervical auricles" of the earlierliterature.4

Finally, the commonest location of these cysts heldby some authors to be of bronchial origin, namely ator near the suprasternal notch, is indeed also thecommon site of the skin orifices of external branchialfistulas, as stressed in an editorial footnote to thecommunication of Constant et al.8We would also re-emphasise the difficulty of

explaining the presence of such cysts in the scapularand shoulder regions, of which our cases 1 and 2 arefurther examples, if one assumes them to be ofbronchial origin. However, if one regards them as ofbranchial origin, no such difficulty is encountered.For whereas late in fetal life the branchial clefts areremote from such ectopic sites as the upper chestwall, upper back and shoulder regions, during theearly stages ofembryonic development, the branchialpouches are in close proximity to those areas des-tined to form these parts of the body, and seques-trated cells from the branchial clefts may be carriedalong with, for example, the developing limb buds.With this postulated development no other associ-ated malformations need be expected. Hence wewould conclude that, although neither a branchialnor a bronchial origin of such cysts can be provenconclusively, a branchial origin appears to be morelikely.The lesion of case 5, unlike the other four, we

regard as of thyroglossal duct origin. Persistence of

Shareef, Salm

the thyroglossal stalk is known to give rise to medialfistulous openings in the neck,9-11 but we areunaware of any previous report with skininvolvement.

We wish to record our gratitude to Dr JW Magner,Cork, and to Dr I Zayid, Halifax, Nova Scotia forgenerously furnishing us with material and clinicalinformation of case 2 and case 5 respectively. We aregreatly indebted to Professor JG Azzopardi for hisinterest and help, and to Professor NA Wright forreading the manuscript. The skilled photomicro-graphy was the work of Mr W Hinkes.

References

Willis RA. Some unusual heterotopias. Br Med J 1968 ;iii:267-72.

2 Fraga S, Helwig EB, Rosen SH. Bronchogenic cysts in theskin and subcutaneous tissue. Am J Clin Pathol 1971 ;56:230-8.

3 Drut R, Castelletto RH, Duclouc KH. Quiste broncogenicode la piel. Med Cutan IberLat Am 1974;2:81-5.

4 Willis RA. The borderland ofembryology andpathology. 2nded. London: Butterworths, 1962:283-9.

6 Filler D, Feustel H, Hermstein N, Maintz J. Die broncho-gene Zyste. Med Klin 1978;73:34-6.

6 Nicholson GW. Studies on tumour formation. Guy'sHospital Reports 1922;72:193-218.

7Bailey H. The clinical aspects of branchial fistulae. Br JSurg 1933 ;21 :173-82.

8 Constant E, Davis DG, Edminster R. Bronchogenic cyst ofthe suprasternal area. Plast Reconstr Surg 1973 ;52:88-90.

9 Schweitzer R. Demonstration eines Rontgenbildes mitoffenem Ductus thyroglossus. Schweiz Med Wochenschr1929;10:250.

10 Sgalitzer KE. Contribution to the study of the morpho-genesis of the thyroid gland. J Anat 1941 ;75:389-405.

Arey LB. Developmental Anatomy. A textbook andlaboratory manual of embryology. 7th ed. Philadelphiaand London: Saunders, 1965:242-3.

12 Seybold WD, Clagett OT. Presternal cyst. Report of a case.Journal of Thoracic Surgery 1945;14:217-20.

Requests for reprints to: Dr R Salm, HistopathologyDepartment, Royal Postgraduate Medical School,Hammersmith Hospital, DuCane Road, London W12OHS, England.