Malignant Chondroid Syringoma: A Diagnosis by Fine Needle Aspiration Cytology

Dear Editor, Chondroid syringomas (CS), also known as a benign mixed tumor of skin, arise from the eccrine and/or apocrine gland. CS are mostly asymptomatic, present as subcutaneous to deep dermal, painless, firm nodules in the head and neck region more commonly than the trunk and back.[1] Malignant chondroid syringoma (MCS) is a very rare neoplasm that is very slow-growing. It is predominantly seen in females and affects the extremities and trunk, whereas its benign counterparts show a predilection toward the male gender.[1,2] On an extensive literature search, we found approximately 51 cases of MCS reported so far on histopathology; however, only 2 cases described cytological features of MCS.[3] Here, we report two cases diagnosed as MCS on cytology, later confirmed on histopathology. Case 1: A 38-year-old female presented with a subcutaneous swelling in the left axillary lesion with overlying ulceration of size 8 cm × 6 cm. The swelling has been present for the past 8 years, with a rapid increase in size in the last 1 year. Fine needle aspiration cytology (FNAC) was done from the swelling showed the presence of epithelial cells and myoepithelial cells (plasmacytoid shape and bland nucleus). Epithelial cells were arranged in groups forming ill-formed glands and singly scattered in an abundant and prominent chondromyxoid background. The epithelial cells had scanty cytoplasm and markedly pleomorphic nuclei with prominent nucleoli. A FNAC diagnosis of malignant skin adnexal neoplasm (possibly malignant condroid syringoma) was made [Figure 1].Figure 1: (a) Photomicrograph showing axillary swelling of size 6 cm × 6 cm with ulceration. (b) Fine needle aspiration cytology (FNAC) smears are highly cellular, showing a biphasic tumor comprised of epithelial cells arranged in groups forming ill-formed glands and singly scattered in a chondromyxoid background (May-Grunwald Giemsa [MGG] 400×). (c) FNAC smears show epithelial cells had scant cytoplasm, markedly pleomorphic nuclei with prominent nucleoli (MGG 400×)The tumor was excised with a wide surgical margin along with axillary lymph node dissection. On histopathological examination, the overlying epidermis was ulcerated. The tumor is composed of malignant epithelial cells embedded within chondromyxoid stroma. The malignant epithelial cells are arranged in irregular nests, ducts, glands, and anastomosing cords. The epithelial cells showed marked pleomorphism, moderate eosinophilic cytoplasm, and hyperchromatic nuclei with irregular nuclear margins. The stroma was heterogeneous, comprising predominantly myxoid material within which malignant cells were embedded. These cells showed marked pleomorphism as well as eosinophilic cytoplasm, irregular hyperchromatic nuclei, and occasional multinucleation. Atypical mitosis was noted along with areas of hemorrhage and necrosis. Present within the dermis adjacent to the aforementioned malignant neoplastic proliferation and distinctly separate from the latter was a benign mixed tumor of skin. Immunohistochemistry reveals the simultaneous presence of luminal cells that were positive for cytokeratin and epithelial membrane antigen (EMA) and myoepithelial cells that were positive for S-100 and vimentin. The patient was clinically well at the time of his last follow-up visit, 6 months post-surgery, with no evidence of local recurrence or metastatic disease. Case 2: A 32-year-old male presented with left cervical swelling of size 2 cm × 2 cm for 1.5 years, which was painless and nonprogressive in nature. Fine needle aspiration smears yielded high cellularity composed of epithelial cells in sheets and also in glands, showing eccentrically placed plasmacytoid cells with moderate anisonucleosis, nuclear atypia, and binucleation dispersed in chondromyxoid stroma. Occasional atypical mitosis was also noted. A diagnosis of MCS was made, which was confirmed on histopathology [Figure 2].Figure 2: (a) Histopathology showing cells arranged in solid nests, cords, and gland-like structures surrounded by chondromyxoid stroma and areas of necrosis (hematoxylin and eosin [H&E] 200×). (b) The histopathology section shows tumor cells embedded in chondromyxoid stroma (H&E 200×). (c) Histopathology section revealed pleomorphic epithelial cells having hyperchromatic nuclei and prominent nucleoli (H&E 600×)Malignant CS are rare adnexal tumors with only 51 cases reported in the literature so far.[3] MCS is a slow-growing tumor characterized painless subcutaneous nodule and untreated for many years, but a rapid increase in size and pain draws attention, which can result in local destruction, metastasis, and can cause death.[1,2] On histopathology examination, these tumors are asymmetric, irregular, with the presence of an epithelial component in tubules or solid aggregates of polygonal or plasmacytoid cells. These tumor cells show mild to marked pleomorphism, bi- or multinucleation, along with abundant mitotic figures with areas of necrosis. The stroma can be myxoid or chondromyxoid, or even osteoid, rarely.[3,4] Histopathologic criteria for malignancy include: nuclear atypia and/or cellular pleomorphism, presence of frequent mitotic figures, an infiltrative growth pattern, presence of satellite nodules, necrosis, and vascular and/or perineural invasion.[4] On cytology, MCS shows increased cellularity with the presence of pleomorphic cells in tubules and cords dispersed in a classical chondromyxoid stroma. Immunohistochemistry can be helpful, by showing expression of a combination of different epithelial and mesenchymal markers – cytokeratins, EMA, S-100, vimentin, carcinoembryonic antigen, and blood group antigen H.[3,4] In the second case, morphological diagnosis was made based on the presence of pleomorphism, necrosis, mitosis, and marked atypia as per in literature by Zufall et al.[3] on it systemic review [Figure 3].Figure 3: (a) Photomicrograph showing a lesion in neck right side of size 2 cm × 2 cm. (b) Epithelial cell clusters in chondromyxoid background (May-Grunwald Giemsa [MGG], 600×). (c) Biopsy shows atypical cells present in cord and nests in a chondromyxoid background (H&E 200×)The differential diagnosis of MCS, both on cytology and histopathology, includes mucinous carcinoma and myxoid chondrosarcoma. The neoplastic cells in mucinous carcinoma show a typical fenestrated pattern with thin septae and with mucinous deposits in between. The mucinous material may mimic chondromyxoid stroma on cytology; however, the fibrillary nature and brilliant magenta color on May-Grunwald Giemsa smears clearly separate later from the former. Present cases had clearly defined chondomyxoid areas with the presence of myoepithelial cells case. Metastatic deposits of myxoid chondrosarcoma of skin show noncohesive, spindle-shaped cells, whereas ductal or tubular formation is seen in MCS.[5,6] Here, we describe cytological findings of MCS, highlighting that FNAC may provide a quick and easy alternative for the diagnosis of such lesions, thus saving time and guiding further management. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published, and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.