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Year : 2020 | Volume
: 37
| Issue : 3 | Page : 151-152 |
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Synovial/ganglion cyst involving the sternoclavicular joint |
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Jasmeet Assi, Laila Khazai
MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030, USA
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Date of Submission | 14-Apr-2020 |
Date of Acceptance | 03-Jun-2020 |
Date of Web Publication | 10-Jul-2020 |
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How to cite this article: Assi J, Khazai L. Synovial/ganglion cyst involving the sternoclavicular joint. J Cytol 2020;37:151-2 |
Synovial/ganglion cysts are common lesions in adults, commonly involving the soft tissue regions of wrist, dorsum of foot or knee. However, rare cases have been reported involving the sternoclavicular joint. Diagnosis in a usual anatomic location is generally made clinically or based on imaging studies alone. The same process in a usual location, however, can pose considerable difficulty in making a diagnosis simply because the clinician, radiologist and pathologist are all caught off guard. Here we present a case of synovial/ganglion cyst involving the sternoclavicular joint, diagnosed by Fine-Needle Aspiration Cytology (FNAC).
A 59-year-old male with a history of infiltrative basal cell carcinoma involving his right posterior shoulder skin, with multiple subsequent recurrences, presented with pathological fracture of his right clavicle. This proved to be recurrence of his basal cell carcinoma on biopsy, promoting systematic evaluation for other possible sites of recurrence or metastasis. On physical examination, the oncologist noticed a small firm lesion in the left suprasternal notch, with “dimpling of overlying skin”. Ultrasound examination of this area showed a hypoechoic nodule measuring 0.7 × 0.6 × 0.6 cm. In light of the recently diagnosed tumor progression, FNA was requested to exclude the possibility of metastasis.
The smears showed rare macrophages in a background of abundant acellular mucoid matrix that appeared as magenta on Diff-Quick and green-blue on Papanicolaou stains [Figure 1]. There were no tumor cells, but the cytologic picture of cyst content together with the peculiar granular mucoid texture of the aspirated material was unexpected as the sample had been labeled as “possible lymph node”. The unusual findings were discussed with the radiologist performing the procedure who reported that after aspiration the lesion collapsed into half its' original size. On second review of ultrasound images, low echogenicity and absence of a fatty hilum in the lesion were interpreted as “more suggestive of a cyst as opposed to a lymph node or a solid soft tissue nodule”. The combination of imaging (well-circumscribed cystic lesion at the sternoclavicular junction) and FNA findings (granular mucoid material displaying folding pattern reminiscent of crinkled plastic food wrap) was considered diagnostic for a synovial/ganglion cyst, with the understanding that definitive distinction between the two entities would only be possible after histologic examination of a resection specimen. | Figure 1: Low and high power appearance of aspirated material. (a) Magenta mucoid material displaying a folding pattern reminiscent of crinkled plastic food wrap on Diff-Quick stain. (b) Higher magnification highlighting the large amount of fine granular debris. (c) Same material staining as green-blue on Papanicolaou stain, with embedded histiocytes. (d) Higher magnification, highlighting the mucoid appearance of cyst content (a and b Diff-Quick, ×20 and 40; c and d, Papanicolaou, ×20 and 40)
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Synovial/ganglion cysts show identical clinical/radiographic features. However, the two lesion are pathologically distinguished from each other based on the presence or absence of a true (cell-lined) wall.[1],[2],[3] As opposed to synovial cyst, the origin of ganglion cysts is somewhat obscure and numerous theories as to their pathogenesis have been proposed including degenerative, traumatic, and metaplastic etiologies. The current most widely held belief is that they develop as a degenerative phenomenon of either fibrous joint or synovial tissue, which explains their anatomical association with tendons or bursae. Both lesions tend to measure about 1.5-2.5 cm in diameter, and patients are usually between the ages of 25-45. The typical presentation is that of an asymptomatic, firm, circumscribed mass. Occasionally, however, lesions can become painful due to compression of an adjacent nerve.
On clinical examination, imaging, and FNA, the differential diagnosis is limited, since soft tissue lesions with a mucoid/myxoid material are more likely to be deep seated, and do not present as a firm circumscribed mass. The clinical finding of a superficial, circumscribed firm lesion in proximity to a joint, and recovery of clear gelatinous fluid are considered characteristic and the diagnosis can be made with confidence despite the lack of specific cytologic findings.[1],[2],[3]
The most characteristic feature of the aspirates is recovery of thick, clear, viscous fluid in the syringe. This material is typically bright magenta color in Diff-Quick and dark green blue on Papanicolaou stains.[1],[2],[3] Examination under low power magnification shows a typical folding pattern reminiscent of crinkled plastic food wrap, while higher magnification highlights scattered histiocytes in background of abundant fine, granular debris.
In conclusion, we present a case of a common lesion in a usual site, which would have been impossible to diagnose had there not been close communication with our radiology colleagues. Even though synovial/ganglion cysts are relatively well described in radiology literature, we could only find one reported case of such lesions in this anatomic location in cytology literature.[4],[5] This case highlights the necessity of detailed clinical and radiologic information when dealing with cytology samples, which by definition are small.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
References | |  |
1. | Dodd LG, Layfield LJ. Fine-needle aspiration cytology of ganglion cysts. Diagn Cytopathol 1996;15:377-81. |
2. | Dodd LG, Mjor NM. Fine-needle aspiration cytology of articular and periarticular lesion. Cancer Cytopath 2002;96:157-65. |
3. | Punia RS, Gupta S, Handa U, Mohan H, Garg S. Fine needle aspiration cytology of bursal cyst. Acta Cytologica 2001;46:690-2. |
4. | Meyerson J, Pan YL, Speath M, Pearson G. Pediatric ganglion cysts: A retrospective review. Hand ( N Y) 2019;14:445-8. |
5. | Sethi D, Lamba S, Gupta B, Swain M. A rare case of ganglion cyst of sternoclavicular joint diagnosed and treated by fine-needle aspiration cytology. J Clin Sci 2017;14:204-6. [Full text] |

Correspondence Address: Dr. Laila Khazai MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston USA
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/JOC.JOC_49_20

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