Unusual presentation of chondroid syringoma of the hand: a literature review and case report.

Introduction

Chondroid syringoma (CS), is a rare benign tumor of eccrine and apocrine glands with epithelial and mesenchymal components, with the potential for malignant transformation and distant metastasis [ 1 ] . The incidence of cutaneous mixed tumors is rare, composing < 0.01% of all primary skin tumors [ 2 ] . These tumors are slow-growing, non-tender, firm dermal or subcutaneous nodules, cysts, or papules, and most lesions are 1–3 cm in diameter [ 3 ] . They are often present for several years without change in size. Excised lesions are usually firm, circumscribed, and shell out quickly from the surrounding tissues [ 4 ] . Histopathological findings include epithelial nests or islands of cuboidal or polygonal cells, tubule-alveolar structures, ductal structures, and a matrix of varying appearances. Keratinous cysts with squamoid cells can also be present [ 4 ] . While benign cutaneous mixed tumors are often found in the head and neck region, malignant mixed tumors are more often found on the trunk and extremities [ 2 ] . Moreover, only five cases of malignant CS have been published in the literature (Table 1 ). Table 1 Summary of the literature on malignant chondroid syringomas First author Publication date Anatomical location Diagnostic method Treatment Kiely, J, L. 1997 Left thenar eminence Histopathology Wide local excision Nicolau, S. 2001 Palmar aspect of right hand Histopathology Wide local excision Medina Henriquez, J. A. 2001 Left fifth metacarpophalangeal joint Histopathology Wide local excision Nguyen, C. M. 2017 Right thumb Histopathology Wide local excision, clear margins. Negative sentinel biopsy. Nakanishi, A. 2018 Left second distal phalanx, volar aspect Histopathology Wide local excision

HIGHLIGHTS Malignant chondroid syringoma (CS) is a slow growing skin tumor with metastatic potential. Malignant CS classically presents in the trunk or proximal extremities. There is limited literature describing its presentation in the hand and the tumor’s aggressive behavior. Delayed diagnosis may occur, presenting as bony erosions, loss of digits, and distant metastases. Given its poor prognosis, early recognition and diagnosis, prompt surgical management, and long-term surveillance are necessary.

We aim to present the case of a 67-year-old Hispanic male who developed a malignant CS appearing on the hand after 5 years of evolution with an aggressive presentation, which was managed with surgical excision. This case report has been reported in line with the SCARE checklist [ 5 ] . Written consent was obtained for the use and publication of the case and its associated images.

Case history

The patient is a 67-year-old male who presented to the emergency department (ED) due to the presence of an ulcerative lesion on the ulnar aspect of his left hand. The patient reported no previous medical history and no surgical history and denied any allergies or drug use. Additionally, the patient denied any family history of cancer. The patient reported that the lesions first appeared approximately 5 years prior as a small nodule to which the patient attributed to an insect bite thus not seeking medical attention. Over the next 3 years, the patient reported that the swelling progressed, eventually involving his fourth and fifth digits. Lesion later progressed with pain and functional impairment, with limited range of motion (ROM) of the involved fingers. Lesion continued to evolve, developing ulceration and bony erosion, resulting in an auto-amputation of the fifth digit, which prompted him to visit the ED. During this same period, the patient reported an unintentional weight loss of approximately 20 pounds. Although the patient had visited his primary care physician during the early swelling phase, he subsequently deferred further medical care until his emergency presentation.

On examination, the patient presented an approximately 4.0 × 3.0 cm open, ulcerative wound on the ulnar aspect of the left hand with absence of fifth digit and deformity of fourth digit associated with limited ROM (Fig. 1 ). Radiographs of the left hand revealed diffuse soft tissue swelling and marked periarticular osteopenia pronounced over the first through the third digits. Extensive destructive changes were evident in the third, fourth, and fifth metacarpals (Fig. 2 ). Juxta-articular periosteal reaction and bony destruction were also noted at the distal radius and ulna. Due to concerns of possible infectious processes, internal medicine and infectious disease service were consulted, recommending prophylactic antibiotic management with vancomycin and cefepime. Figure 1. The initial appearance of the tumor (A, B, C, D, and E) is described as an open wound on the ulnar aspect of the left hand with an absent fifth finger and a grossly deformed and flexed ring finger. Figure 2. Anteroposterior (A), oblique (B), and lateral (C) left hand X-rays. Diffuse soft tissue swelling of the hand, diffuse periarticular osteopenia, most prominent on the first, second, and third digit. Extensive destructive changes on third, fourth, and fifth metacarpals, most notable on the fourth digit. Juxta-articular osteoporosis noted at the distal radius and ulna with periosteal reaction on distal radius.

A non-contrast computed tomography (CT) performed at this time showed significant soft tissue defect associated with thickening of the subcutaneous tissues along the ulnar aspect of the hand (Fig. 3 ). Additional findings included diffuse reticular pattern of the subcutaneous tissues, trace-free fluids, and soft tissue edema along the left forearm and hand. At this time, based on initial examination and radiographic evaluation, the differential diagnosis included infectious process versus neoplasm. Subsequent magnetic resonance imaging (MRI) of the left hand revealed extensive soft-tissue swelling at the wrist and metacarpal compartments with heterogeneous high-intensity signal changes surrounding the third to fifth metacarpals, suggesting inflammatory changes consistent with osteomyelitis or an underlying malignancy (Fig. 4 ). Given findings, the patient was admitted into the Oncologic Orthopaedic Surgery Service for further evaluation and management. Figure 3. Coronal (A, B, C, and D) left hand non-contract computed tomography series of the left hand. Significant soft tissue defect associated with thickening of the subcutaneous tissues along the ulnar aspect of the hand with diffuse reticular pattern of the subcutaneous tissues, trace-free fluids, and soft tissue edema along the left forearm and hand. Figure 4. Axial (A and B) and coronal (C and D) views of left hand MRI. Extensive soft-tissue swelling at the wrist and metacarpal compartments with heterogeneous high-intensity signal changes surrounding the third to fifth metacarpals, consistent with underlying pathology or infectious origin.

Chest and abdominopelvic CT scans revealed multiple lytic lesions involving the right ilium, S1–S2 vertebral bodies, and right femoral neck. Thoracic CT demonstrated various osteolytic lesions throughout the lower cervical and upper thoracic vertebral bodies without signs of compression or involvement of dural sac (Fig. 5 ). Additionally, a lesion was identified within the sternum. Differential diagnosis at this stage included multiple myeloma, squamous cell carcinoma, and Majorine ulcer. Oncology service was consulted as multiple myeloma was strongly suspected due to the presence of multiple lytic lesions on imaging; however, initial hematologic/oncologic workup returned negative. Figure 5. Thoracic CT (A and B) showing multiple osteolytic lesions throughout the lower cervical and upper thoracic vertebral bodies without signs of compression or involvement of dural sac.

Given the presence of an ulcerative lesion, progressive loss of function, imaging findings concerning for malignancy, and clinical examination suggestive of health risk, excisional biopsy through amputation was pursued as both diagnostic and therapeutic intervention. Given surgical planning, plastic surgery was consulted for recommendations, to which they agreed with the surgical plan. Prior to surgery, antibiotic therapy was halted, given infectious disease service recommendations in order to maximize tissue culture yield. On gross examination, the specimen measured 4.0 × 3.0 × 2.6 cm, appearing tan and homogeneous, involving skin, subcutaneous tissue, and underlying bone. The tumor extended to the inked margins. Histopathological analysis of tissue demonstrated naked atypical and diffusely infiltrative-appearing cords, with ductal structures composed of enlarged, frankly atypical, and pleomorphic appearing tumor cells with hyperchromatic staining nuclei (Figs 6 and 7 ). Immunohistochemistry was positive for S-100, focally positive carcinoembryonic antigen, and positive CA-9/19, consistent with malignant chondroid syringoma. Intraoperative cultures were taken, which later were positive for Pseudomonas aeruginosa and Staphylococcus lugdunensis , for which the infectious disease team started antibiotic management. Patient presented with a normal postoperative course, able to be discharged home at 4-days post-op with scheduled follow-up appointments with Oncologic service, internal medicine service, and Orthopaedic surgery service. Figure 6. A. H&E 10×, acral skin with underlying dermal tumor; B. H&E 20×, mixed tumor with epithelial component arranged in a glandular and tubular structure within a chondroid matrix; C. H&E 40×, glandular structures with atypical cells with hyperchromatic nuclei and scant cytoplasm within a hyaline chondroid matrix; D. H&E 60×, markedly enlarged, atypical cells with hyperchromatic nuclei and scant cytoplasm within a spindle cell stroma; E. H&E 40×, focal necrosis; F. H&E 60×, few mitotic figures; G. H&E 20×, perineural invasion; H. H&E 40×, lymphovascular invasion. Figure 7. A. 20×, nests of cuboidal cells with strong expression for cytokeratin-7 (CK7) immunostain; B. 20×, tumor focally positive for CA19-9 immunostain; C. 20×, tumor focally positive for monoclonal carcinoembryonic antigen immunostain; D. 20×, tumor focally positive for S-100 immunostain.

Postoperatively, the patient was seen at the 1-month postoperative follow-up, presenting with a healed surgical site without signs of infection or wound complication. The patient did report minimal pain at the surgical site but was able to manage with acetaminophen. As per Oncologist recommendations, the patient had performed a Lymphoscintigraphy with evidence of severe lymphatic disruption of the left upper extremity. He was subsequently evaluated at the 2-month mark, being monitored jointly with the Internal Medicine and Oncology teams. Interventional Radiology was consulted by the medicine team for a biopsy of a sternum lesion identified on imaging. Despite multiple efforts, the patient was difficult to reach and was only intermittently contacted by our service via phone. At approximately 6 months post-op, the patient only reported worsening back pain and fatigue. According to the patient, his oncologist had confirmed disease progression; however, no updated radiographs or clinical records were available for review.

The patient was prescribed systemic chemotherapy by his oncologist, though he reported poor tolerance with significant nausea, fatigue, and weight loss. According to the patient, chemotherapy was discontinued due to worsening functional decline and increasing pain suggestive of limited therapeutic response. The patient was subsequently transitioned into palliative care and ultimately passed away 2 years after presentation.

Discussion

Sweat gland carcinomas are rare skin tumors that can be easily misdiagnosed and are generally associated with a prolonged course and a poor prognosis [ 6 ] . Malignant CS often presents as non-specific, painless subcutaneous nodules and goes untreated for months as they show little concern to patients. It is usually growth and pain that prompt patients to seek medical attention. Our patient presented with a slow-growing swelling with a 5-year evolution.

Zufall et al found that gross characteristics of the tumor, tumor size greater than 5 cm, and truncal tumor location were associated with a higher risk of metastasis [ 7 ] . Our case had a tumoral lesion measuring 4 × 3 × 2.6 cm, located on the hand, and with metastatic disease on presentation. Also, while MCS tumors are commonly located on the extremities, truncal lesions had a higher metastatic risk [ 7 ] . Differentiating sweat gland carcinoma from other skin malignancies is essential clinically because prognosis and treatment differ from the more commonly encountered basal and squamous cell carcinoma [ 6 ] .

Imaging is not typically used to diagnose, but more so to evaluate for metastasis and lymphadenopathy on a suspected malignancy. Nicolau et al suggested that while MRI may yield non-specific findings, it can help describe the anatomical extent of the lesion, including location, tissue of origin, and depth of invasion [ 6 ] . Our case presented with soft tissue swelling. Fine needle aspiration cytology may help confirm a diagnosis of malignant CS when unclear. Features suggesting malignancy include increased cellularity, a hemorrhagic background, and discohesive pleomorphic epithelial cells in ill-forming cords.

On the other hand, Zufall et al. concluded in their systematic review that those malignant CS greater than five cm and those located in the trunk should be treated with a wide local excision and followed closely as they were found to have a greater risk of metastasis [ 7 ] . Wide local excision with clear margins is the standard of treatment. Our case had a lesion involving a hand. Ray’s amputation specimen disclosed disease in the margins. However, the patient already had metastatic disease. In their systematic review of 51 patients with malignant CS, Zufall et al . found a metastasis rate of 35% and a mortality rate of 18% [ 7 ] . They failed to associate typical malignant features in histology with metastatic risk. However, lesions with frequent mitotic figures had a high rate of metastasis. Patients with truncal lesions had the highest rate of metastasis, with 75%. However, those with lesions on extremities were not far behind with 65% [ 7 ] .

Malignant CS tumors of the hand are rare lesions that have the potential to metastasize and be lethal, as reported in our case. Careful monitoring of these patients is essential, especially if the lesion is large and in the trunk. This case report offers insight into this pathology and its unusually slow growth and metastatic presentation.

Conclusion

Malignant chondroid syringoma is a rare tumor with unpredictable behavior and potential for distant metastasis, even without classic high-risk features. This case emphasizes the need for suspicion in chronic cutaneous lesions with progressive symptoms. Early diagnosis, complete excision, and close follow-up are essential, and further research is needed to guide management.

Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article.

Published online 10 February 2026

Ethical approval

This study is a case report and does not require ethical approval from our institution’s IRB. The patient was not physically involved in the research and only previously collected data was used. However, we have complied with HIPAA to protect the patient’s information.

Consent

The patient gave written informed consent for publication and accompanying images. Upon request, the editor-in-chief of this journal can review a copy of the written consent form.

Sources of funding

No funding was received for this research.

Author contributions

J.D.-A.: Conceptualization, Data collection, Literature review, Manuscript drafting, Critical revision; J.I.A.J.: Data collection, Conceptualization, Manuscript drafting, Critical revision, Final approval, Supervision; J.A.S.A.: Literature review, Manuscript editing, Manuscript revisions, Figure preparation; J.B.: Critical revision, Final approval, Supervision.

Conflicts of interest disclosure

No conflicts of interest.

Research registration unique identifying number (UIN)

Not applicable.

Guarantor

José I. Acosta Julbe, MD (corresponding author) is the guarantor of this study. This manuscript submitted does not contain information about medical device(s)/drug(s). No relevant financial activities outside the submitted work.

Provenance and Peer Review

This article was an original, uncomisioned case report which was internally peer-reviewed.

Data Availability Statement

The data regarding the findings of this case report are not publicly available to protect patient confidentiality. Request for furthr information regarding clinical data may be directed to the corresponding author.

Acknowledgements

The authors acknowledge the support of the administrative staff Department of Orthopedic Surgery at University of Puerto Rico.

Support

The authors received no support for this study.

Declaration of generative AI and AI-assisted technologies in the writing process

This work’s author(s) did not use AI and AI-assisted technologies in writing.

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