SOX10-Internal Tandem Duplications and PLAG1 or HMGA2 Fusions Segregate Eccrine-Type and Apocrine-Type Cutaneous Mixed Tumors

Cutaneous mixed tumors exhibit a wide morphologic diversity and are currently classified into apocrine and eccrine types based on their morphologic differentiation. Some cases of apocrine-type cutaneous mixed tumors (ACMT), namely, hyaline cell-rich apocrine cutaneous mixed tumors (HCR-ACMT) show a prominent or exclusive plasmacytoid myoepithelial component. Although recurrent fusions of PLAG1 have been observed in ACMT, the oncogenic driver of eccrine-type cutaneous mixed tumors (ECMT) is still unknown. The aim of the study was to provide a comprehensive morphologic, immunohistochemical, and molecular characterization of these tumors. Forty-one cases were included in this study: 28 cases of ACMT/HCR-ACMT and 13 cases of ECMT. After morphologic and immunohistochemical characterization, all specimens were analyzed by RNA sequencing. By immunohistochemistry, all cases showed expression of SOX10, but only ACMT/HCR-ACMT showed expression of PLAG1 and HMGA2. RNA sequencing confirmed the presence of recurrent fusion of PLAG1 or HMGA2 in all cases of ACMT/HCR-ACMT, with a perfect correlation with PLAG1/HMGA2 immunohistochemical status, and revealed internal tandem duplications of SOX10 (SOX10-ITD) in all cases of ECMT. Although TRPS1::PLAG1 was the most frequent fusion, HMGA2::WIF1 and HMGA2::NFIB were detected in ACMT cases. Clustering analysis based on gene expression profiling of 110 tumors, including numerous histotypes, showed that ECMT formed a distinct group compared with all other tumors. ACMT, HCR-ACMT, and salivary gland pleomorphic adenoma clustered together, whereas myoepithelioma with fusions of EWSR1, FUS, PBX1, PBX3, POU5F1, and KLF17 formed another cluster. Follow-up showed no evidence of disease in 23 cases across all 3 tumor types. In conclusion, our study demonstrated for the first time SOX10-ITD in ECMT and HMGA2 fusions in ACMT and further refined the prevalence of PLAG1 fusions in ACMT. Clustering analyses revealed the transcriptomic distance between these different tumors, especially in the heterogenous group of myoepitheliomas.

Hyaline cell-rich chondroid syringoma: A potential pitfall on cytology

Chondroid syringoma is a rare adnexal tumor of skin, with few cases diagnosed on fine needle aspiration cytology (FNAC). Hyaline cell-rich chondroid syringoma (HCRCS) is a very uncommon variant of chondroid syringoma described in histopathologic studies. This variant differs from the usual chondroid syringoma in its site of presentation, cytohistologic features, and morphologically mimics malignant neoplasms. To the best of our knowledge, cytologic features of this entity have never been described. This case report highlights some unusual features of this tumor and discusses the cytologic features of HCRCS along with neoplastic mimics.

Cutaneous Mixed Tumour: A Rare Presentation of a Scrotal Lump Mimicking an Accessory Testis

Cutaneous mixed tumour (CMT), also known as chondroid syringoma (CS), is a rare benign tumour composed of epithelial, myoepithelial, and mesenchymal components with an incidence of less than 0.01% of primary skin tumours. It is more common in males and typically presents as a painless slow-growing firm mass in the subcutis of the head and neck region. Genital regions are very rarely involved. We present the case of a 50-year-old male with a 10-year history of an asymptomatic gradually enlarging mass in the upper scrotum. A surgical excision was performed. Microscopic examination showed features of CMT. This case highlights the diagnostic challenges associated with scrotal CMT and surgical management of these lesions. Additionally, we endorse the recommended terminology of CMT used by the fifth edition of WHO Classification of Skin Tumours (2023).

A Once-Thought Lipoma Turned Malignant Chondroid Syringoma

Chondroid syringoma is a relatively rare benign skin appendageal tumor with an incidence of <0.098%. Malignant chondroid syringoma (MCS) arises from cutaneous sweat glands and occurs on the extremities or trunk more commonly in women with only 51 reported cases. Due to the rarity of the disease and lack of published cases of MCS, the diagnostic criteria and treatment protocols are not clear. Based on available recommendations and histological criteria, MCS was diagnosed in a previously classified elbow lipoma following increased size and pain, and skin color changes in a 65-year-old woman.

Benign Chondroid Syringoma on Chin: A Case Report and Literature Review

Chondroid syringoma is a cutaneous adnexal tumor originating from sweat glands origin. It is rare in occurrence and usually benign, having an incidence of 0.01 to 0.098%. As these tumors are uncommon, their diagnosis is missed many times and are misdiagnosed. Hence in any case of facial skin swelling increasing slowly in size, this entity should be kept in mind as one of the possibilities and differential diagnosis. Histopathological examination of the excision biopsy gives the definitive confirmatory diagnosis. Surgically excising the swelling locally along with a surrounding normal tissue cuff is the standard treatment given which prevents recurrence. Hereby we present a 35-year-old case of facial chondroid syringoma having a focal component of eccrine hidrocystoma, keratinous cyst as well as syringocystadenoma papilliferum on the chin that was clinically suspected to be an epidermoid cyst or mucocele.

Chondroid syringoma of the axilla: A potential for misdiagnosis as metastatic carcinoma on fine needle aspiration cytology

Chondroid syringoma is a rare benign adnexal tumor and tends to occur in the head and neck region. Involvement in the axilla is very unusual, and the differential diagnosis of such presentations includes lymphadenopathy and cyst. Fine needle aspiration cytology (FNAC) is a very useful tool for the diagnosis of chondroid syringoma. The characteristic feature of chondroid syringoma in cytology is the presence of distinct biphasic cell populations of epithelial and myoepithelial cells in the chondromyxoid stroma. If the typical biphasic cellular and chondromyxoid stromal elements are not visible in smears, it may be misdiagnosed in cytology. Here, we describe a case of axillary chondroid syringoma that was initially misdiagnosed as a metastatic carcinoma by FNAC. Although chondroid syringoma rarely occurs in the axilla, it should be included among the differential diagnoses of an axillary mass. Cytopathologists need to discern the unique cytological features of chondroid syringoma and avoid misdiagnosis for prompt management of the patient.

Cutaneous pleomorphic adenoma of the periocular region - a case series

Mixed tumour of the skin is a rare entity also known as chondroid syringoma and pleomorphic adenoma. These usually present as slow-growing skin nodules with a smooth surface, clear boundaries, and no ulceration. Case series exist describing pleomorphic adenomas in the periocular region including the lids and orbit, separate to the more familiar lacrimal gland pleomorphic adenoma. These may arise from accessory or ectopic lacrimal gland tissue but in the eyelids are more likely to arise from sweat glands in the skin. Histopathological analysis of these lesions is important to identify complete excision, minimising recurrences and in identifying rare but potential malignant transformation. We describe the clinical features and outcomes in three cases of pleomorphic adenoma with two at the medial canthus (including one recurrence) and one in the brow region.

Proptosis Revealing a Rare Lacrimal Gland Tumor: A Case of Chondroid Syringoma in a 35-year-old Patient

Lacrimal gland chondroid syringoma is a very rare tumor with classic clinico-radiological symptoms that should be familiar to clinicians for appropriate patients’ management as the tumor has potential for recurrence and malignant transformation. We report herein a case of chondroid syringoma in a 35-year-old patient presenting with progressive painless proptosis for 2 years. He underwent complete surgical removal of the tumor, with subsequent clinical improvement of his symptoms.

Cytodiagnosis of chondroid syringoma-Series of three cases

Chondroid syringoma is a rare, benign, appendegeal neoplasm. It was initially termed as mixed tumor as it comprises both epithelial cells and chondromyxoid stroma. It usually presents as a slow growing, solitary, painless, subcutaneous, or intracutaneous mass, frequently in the head and neck region. Cytological features usually include the presence of both components, similar to histology but aspiration of only one component or atypical features can pose challenges in diagnosis. According to literature, only a few single case reports describing the cytological features of chondroid syringoma has been published. We report three cases of chondroid syringoma and its differential diagnosis on cytology.

An atypical chondroid syringoma with malignant degeneration: Utility of comparative genomic hybridization in confirming the diagnosis

Chondroid syringoma (CS) represents the cutaneous counterpart of mixed tumor (pleomorphic adenoma) of salivary glands. Definitive diagnosis is made on histopathology and is based on the presence of characteristic epithelial and stromal components. We report a case of an atypical CS arising on the extremity of an elderly male patient. Histomorphologic features of necrosis and cellular atypia raised suspicion for malignant degeneration, an exceptionally rare circumstance in this context. To further support the diagnosis of malignancy, array comparative genomic hybridization was performed from both low and higher grade areas of the tumor. Both regions demonstrated multiple copy number gains and losses, with additional loss of q7p (TP53), loss of 19p, and loss of heterozygosity on16q demonstrated in the more atypical foci. To our knowledge, this is the first case description of malignant degeneration of a CS with correlative microarray analysis. The findings in this case may prove useful in confirming the diagnosis in future ambiguous cases.

Malignant Chondroid Syringoma With Nose and Paranasal Sinus Extension: A Case Report

Chondroid syringoma is a rare, skin appendageal tumor. It is also known as mixed tumor of skin, as it histologically resembles mixed tumor of salivary gland (pleomorphic adenoma). It is most commonly a benign tumor, but a few malignant counterparts have been described in history. It usually presents as a solid, slow-growing, solitary, and painless nodule in the head and neck region. Malignant counterpart is rare and commonly affects trunk and extremities. Early diagnosis and surgery by wide local excision are the most reliable treatments to date. Recurrences are common and hence close follow-up is advised. In this study, we present a case of malignant chondroid syringoma of face with extensive extension into nose and paranasal sinuses, which was recurrent and managed by surgical excision and radiotherapy. To the best of our knowledge, this is the first reported case with extension and bone destruction into nose and sinuses.

A Rare Forehead Mass: The Chondroid Syringoma

The chondroid syringoma is an extremely rare skin tumor most commonly found in the area of the head and neck region. Its rarity, potential for malignancy, and frequent misdiagnosis for other more common tumors can impart unique challenges in diagnosis and management. Diagnosis is usually revealed by excision followed by histologic examination. We report a case of a 42-year-old male with no prior medical history diagnosed with chondroid syringoma of the forehead and review the relevant literature.

Fine needle aspiration cytology as a preliminary diagnostic tool in chondroid syringoma: a case report and review

We report a case of chondroid syringoma (CS) in a 44-year-old male. He presented with a firm asymptomatic nodule in his left upper lip of 2-year duration. The initial clue to the diagnosis was made on fine needle aspiration cytology (FNAC), and a final diagnosis was based on histopathological examination. The case highlights the importance of FNAC in providing clues to the diagnosis of suspected cases of chondroid syringoma before performing large excisions and repair, which would require more skill and time. We have also reviewed the cytological findings of all the cases of benign CS reported until the current date.

Clinical and pathological study on mixed tumors of the skin

Mixed tumor of the skin (MTS) is a rare benign tumor of the sweat glands with a reported frequency of 0.01% to 0.098%. The objective of the study is to investigate clinicopathological and immunohistochemical features of mixed tumor of the skin.This was a retrospective study of 21 patients diagnosed with MTS at the Institute of Dermatology and Venereology of Sichuan Provincial People's Hospital from 1980 to 2016. Pathological sections of all cases were reread and the diagnosis was verified.There were 14 males (67%) and 7 females (33%). MTS affected the face. The lesions were skin-colored or lightly red, with no subjective symptoms in most cases. Histopathologically, the tumors consisted of epithelial and interstitial components. The epithelium was mainly composed of cubic or polygonal cells, which can be seen within the tubule-like structures with bilayer epithelium. The inner cells mainly expressed cytokeratin and other epithelial markers. The outer cells expressed epithelial and mesenchymal markers. The outer cells expressed S-100, P63, and glial fibrillary acidic protein. The tumors showed interstitial mucus-like and fibrosis changes, and some parts had cartilage-like changes.Pathological diagnosis is particularly important because the clinical symptoms of MTS lack specificity.

A rare large cutaneous chondroid syringoma involving a toe: A case report

RATIONALE

Chondroid syringoma (CS) occurs mostly on the face and neck, and rarely occurs in the toe. Malignant CS is invasive, grows quickly, and has a high recurrence rate. The presence of a bilobed CS in 1 toe has never been reported in the literature.

PATIENT CONCERNS

A 72-year-old male patient presented with a mass in a third toe of his right foot. The mass had slowly grown in 2 years. He felt mild pain and the mass occupied most of the tip of the toe.

DIAGNOSES

Radiographs showed a large soft-tissue mass in the third toe of his right foot without any bone destruction. Ultrasonogram showed 2 partly fused hypoechoic masses within the lesion. The mass was therefore diagnosed as a benign CS.

INTERVENTIONS

We amputated the toe with the mass under local anesthesia. The postoperative pathohistological examinations confirmed that the lesion was a bipartite CS exhibiting active cellular proliferation.

OUTCOMES

Two years after surgery, there was no tumor recurrence.

LESSONS

CS can also present as multiple adjacent masses. Complete surgical resection and long-term follow-up are essential.

Benign chondroid syringoma affecting the upper lip: Report of a rare case and review of literature

Chondroid syringoma (CS) (mixed tumor of the skin) is a rare neoplasm of the sweat glands, which presents itself as a slow-growing, painless, nonulcerated, subcutaneous or intracutaneous mass often occurring in the head and neck region. The clinician may miss the diagnosis of this lesion due to its rarity. CS should be considered in the differential diagnosis of any subcutaneous nodules, especially in the head and neck region. The diagnosis of CS is mainly based on the histopathologic examination. This article presents a 35-year-old male with a mass on the upper lip that was histopathologically diagnosed as an apocrine variant of benign CS with squamous metaplasia after surgical excision. No sign of recurrence is evident till date during the follow-up. We report this case because of its rarity. A brief literature review and all the reported cases in the lip have been listed.

Chondroid Syringoma

Chondroid syringoma is a cutaneous sweat gland tumor. Despite its relative rarity, a benign and malignant variant have been described. We present a case report of chondroid syringoma of the foot in a healthy patient. Definitive diagnosis required histopathologic examination, while treatment included wide resection. Surgeons who are presented with a painless, solid nodule in the lower extremities should be cognizant of this neoplasm.

LEVELS OF EVIDENCE

Therapeutic, Level IV: Case report.

Local recurrence of cutaneous mixed tumor (chondroid syringoma) as malignant mixed tumor of the thumb 20 years after initial diagnosis

Benign cutaneous mixed tumor (chondroid syringoma) is the cutaneous counterpart of the benign mixed tumor (pleomorphic adenoma) of salivary glands, consisting of both epithelial and mesenchymal elements. The incidence of cutaneous mixed tumor is rare, composing <0.01% of all primary skin tumors. Herein, we report a case of malignant mixed tumor which recurred in the right thumb 20 years after the reported initial diagnosis of a benign mixed tumor at this site. Histologically, the lesion consisted of highly atypical and infiltrative cells in cords and ductal structures, with an adjacent focus of residual benign mixed tumor present. Perineural invasion of multiple dermal and subcutaneous nerves was also seen. Immunohistochemical staining was strongly and diffusely positive for CK5/6 and p63, with patchy positive S100 and CK7 staining. Wide excision was performed, with no evidence of recurrence or metastasis 5 years later.

Chondroid syringoma of the axilla: An unusual tumor diagnosed by fine needle aspiration

Chondroid syringoma (CS) is a rare benign adnexal tumor of the skin with a resemblance to pleomorphic adenoma of salivary gland, most commonly involving the head and neck region. In the present literature, reports of the cytologic appearance of CS are scarce as it is rarely encountered by fine needle aspiration (FNA). A 67-year-old woman presented with a 1 year history of a 1 cm subcutaneous nodule in the right axilla. FNA biopsy was performed revealing an epithelial-mesenchymal biphasic neoplasm suggesting CS. Surgical excision confirmed the diagnosis and demonstrated extensive ossification, an extremely rare feature, with only seven reported cases, all located on the head. CS is a rare benign adnexal tumor of the skin, often overlooked due to its unremarkable clinical presentation. FNA is a reliable tool for the diagnosis of CS and helps guide optimal surgical management.

Giant benign Chondroid Syringoma in the elbow

Chondroid syringoma (CS) is a rarely seen benign tumor rooted in the epithelial and mesenchymal cells of the skin. It is generally localized in the head and neck region and rarely in the extremities. A case is presented here of a giant CS in the rarely seen location of the elbow. A 55-year old male presented at our hospital with the complaint of a slow-growing painless mass in the left elbow. On the left elbow radiograph, mass opacity was observed with a regular border surrounded by a fine radiolucent line within the subcutaneous tissue adjacent to the humerus in the posterior of the elbow. On the contrast elbow MRI mass was observed lobular contours, a regular border and isointensity to muscle in the subcutaneous fat plans. Hypointense linear images were observed in the mass. The lesions demonstrate evident enhancement. An excisional biopsy was performed. A diagnosis of benign CS was made histopathologically. Especially in the differential diagnosis of slow growing cutaneous and subcutaneous nodules in the extremities, CS should feature when fibrous septa are seen on MRI.

Giant chondroid syringoma with divergent differentiation: Cyto-histo-immuno correlation

Chondroid syringoma is a rare benign skin adnexal tumor of eccrine/apocrine origin affecting commonly the head and neck region. It is also called as mixed tumor of skin because of the presence of both the epithelial and mesenchymal components. There are very few case reports of chondroid syringoma diagnosed on fine needle aspiration cytology (FNAC). We hereby report a case of giant chondroid syringoma occurring over the lower back in a 50-year-old male, diagnosed initially on cytology and confirmed by histopathology. This case is reported for its unusual size and site of occurrence. We describe the clinical features, cytology, histopathology, immunohistochemistry, and differential diagnosis of giant chondroid syringoma along with review of literature.

Chondroid syringoma with extensive ossification

Chondroid syringoma is a rare appendagel skin tumor. Due to its uncharacteristic presentation, it is rarely diagnosed clinically. Here we present one such case in a 50-year-old lady. She presented with a hard mobile lesion over her nose which was excised. The histologic picture is characterized by a combination of epithelial and myoepithelial structures within a chondromyxoid and fibrous stroma. For these tumors, excision is the treatment of choice.