CASE REPORT
A 32-year-old female with an unremarkable medical history presented to the clinic with a small, non-tender, and erythematous nodule on the dorsolateral aspect of her left arm, which initially appeared three months before. Since then, the nodule had slowly darkened and grown to 1 cm ×1 cm in size. Her history and physical exam were insignificant except for multiple warts on the dorsal aspect of the right hand. (Figure 1). Initially, the patient was suspected of having an infectious cyst and was treated with 10-days of antibiotics. However, she was unresponsive to antibiotics and was evaluated by a surgeon, who diagnosed the lesion as an abscess and surgically removed it.
After two weeks, a rapidly growing mass measuring 4 cm ×4 cm originated from the incised area. The mass was surgically excised again but reappeared within one week, measuring 5 cm ×5 cm, after which the patient was referred to our hospital for further evaluation. The magnetic resonance imaging (MRI11We first met the patient after her last surgery. Unfortunately, the patient did not take any pictures from the arm mass at the disease onset and intervals between surgeries.) of the left arm with and without contrast showed multiple enhancing lesions at the subdermal region of the posterolateral aspect of the left arm with multiple enlarged axillary lymph nodes, the largest of which measured approximately 17 mm, suggestive of metastasis. The tumor was radically excised with negative surgical margins. Microscopic examination of the lesion demonstrated a neoplastic round cell tumor with prominent foci of necrosis (Figure 2). IHC staining revealed neoplastic cells with positive expression for CD99, Ck20, and NSE (Figure 2), but no LCA, Vimentin, CD3, CD20, and HMB45 expression consistent with MCC (Figure 3). Also, The MCPyV PCR real-time of the lesion was positive.
High-resolution computed tomography (HRCT) Scan of the chest and abdominopelvic area with and without contrast showed lymphadenopathy 39 mm×25 mm in the left axillary fossa along with a calcified lymph node (6mm) in the abdominal cavity beyond the left abdominal muscle. She was diagnosed with stage III MCC and subsequently treated with adjuvant radiation to her left arm and axilla with 45.0 Grays (Gy) of radiation in 35 fractions, followed by six cycles of chemotherapy with etoposide and cisplatin. The patient’s post-treatment PET/CT scan showed no evidence of neoplastic disease and supported remission. However, high-dose chemotherapy caused frequent myalgias and weakened immune system. Unfortunately, she developed febrile neutropenia and expired due to septic shock one month after the last chemotherapy course.