Cytodiagnosis of a herniated disk presenting as a soft tissue mass. A case report

Sequestered disc herniation mimicking psoas abscess: A rare case report

Intervertebral disc herniation is common condition, with majority occurring in lumbar and cervical spine. Most lumbar disk herniations occur within the spinal canal, with approximately 7%-10% identified within the foramen or extraforaminal location. Extraforaminal disc herniation in extreme lateral, retroperitoneal or anterior terms are used when disc material is seen towards anterolateral or anterior to the spine. Disc herniation in these locations is easily mistaken for an abscess or a neoplasm especially when it is not connected to the parent disc (sequestered disc). We describe a case of 60-year male who initially was misdiagnosed as psoas abscess and subjected to invasive investigation which later turned out to be histologically confirmed disc sequestration in the retroperitoneum. Thus, knowledge of this condition is essential in avoiding unnecessary workup and treatment.

Degenerative Disc Disease Mimicking Spondylodiscitis with Bilateral Psoas Abscesses

BACKGROUND

Sequestered disc fragments may present as a lesion with peripheral enhancement on magnetic resonance imaging. When located in the psoas muscle compartment, this finding could mimic an abscess.

CASE DESCRIPTION

We describe a case of a 52-year-old man who returned from Togo after 2 years of living in precarious conditions. He was afebrile and complaining of lumbar back pain. The magnetic resonance imaging showed L3 and L4 vertebral body enhancement with bilateral psoas lesions in continuity with the disc space, suggesting spondylodiscitis with a differential diagnosis of inflammatory herniated disc. A computed tomography-guided biopsy of the right psoas lesion was performed to rule out spondylodiscitis. Histology was compatible with extruded disc material.

CONCLUSION

Herniated disc fragments should be considered as a differential diagnosis of psoas abscesses. Coronal plane images may show the continuity of bilateral herniated disc fragments, mimicking psoas abscesses.

Sequestered disc fragment mimicking a psoas abscess

BACKGROUND CONTEXT

If a herniated lumbar disc fragment extrudes and migrates away from the spinal column, the radiographic appearances can be confusing.

STUDY DESIGN

In this article, we report a rare case of a sequestrated disc fragment in the psoas muscle, discrete from the adjacent disc space, which presented with features similar to a psoas abscess on imaging studies.

CONCLUSIONS

It is vital that in such cases the correct diagnosis is made to avoid unnecessary treatments and inappropriate management.

Cytopathologic analysis of paraspinal masses: a study of 59 cases with clinicoradiologic correlation

Paraspinal masses (PSM) are uncommon and present a wide spectrum of differential diagnoses on fine-needle aspiration (FNA). We analyzed 59 cases of PSM on FNA in a 15-yr period, in the context of clinicoradiologic correlation. Radiologic findings, clinical data, and tissue biopsies were reviewed. Patients were 14-83 yr of age (mean 54.7) with a M:F ratio of 1.36:1. Of the 59 cases, 39 (66%) were deemed diagnostic. Of these, 8 (21%) revealed nonneoplastic lesions and 31 (79%) yielded neoplasms: 2 (6%) benign and 29 (94%) malignant. Of the malignant cases, 22 (76%) were metastatic tumors from various sites, while 7 (24%) were cancers from local spread, which included non-Hodgkin's lymphoma (NHL, 5) and myeloma (2). Benign neoplasms were nerve sheath tumors. Metastatic tumors consisted of adenocarcinoma, 9; squamous-cell carcinoma, 3; renal-cell carcinoma, 1; and non-small-cell carcinoma/not otherwise specified (NOS), 9. Twenty-four (41%) cases received further studies: immunoperoxidase (IPOX) alone, 17 (71%); special stains for microorganisms, 2 (8%); IPOX/other special stains, 4 (17%); and flow cytometry analysis, 1 (4%). Eight (14%) cases received follow-up biopsies. Half of these biopsies added information to previously "nondiagnostic" FNAs. Of the previously "diagnostic" FNAs, tissue biopsy yielded no additional information. Cytopathologic diagnoses were consistent with the pre-FNA radiology analyses in 13 (39%) cases. In instances of radiologic and cytopathologic discrepancy (4 cases, 12%), diagnoses made by FNA reversed the initial radiologic impression of neoplasm to infection, and vice versa. PSMs are rare lesions (0.26% of total FNAs done in 15 yr at our institution). The most common lesion encountered is metastatic adenocarcinoma, followed by NHL. Ancillary studies are helpful in difficult cases. In cases of radiologic/cytopathologic discrepancy, FNA diagnoses are more accurate and decisive for patient management. The sensitivity and specificity of a PSM FNA are 88% and 75% respectively.