Title : Chromoblastomycosis with transformation to invasive squamous cell carcinoma: Oncological complication of a neglected mycosis
Abstract:
A 71-year-old male patient, a farmer, originally from and residing in Petén, presented with a history of a nodular lesion on his left upper extremity, extending into the midarm region, which had begun 31 years prior. The patient was unable to describe how the lesion began or triggered it. He had previously consulted at a tertiary care hospital, where a biopsy was performed and antifungal treatment with fluconazole was initiated, without clinical improvement. Due to the lack of therapeutic response, the patient discontinued treatment and did not continue medical follow-up.
The patient reported progressive growth of the lesion, associated with ulceration, pain, foul odor, and functional limitation of the affected limb, prompting him to seek medical attention. Physical examination revealed a chronic dermatosis localized to the left upper extremity, characterized by multiple erythematous nodules forming verrucous plaques with intense scaling. and an ulcerated exophytic lesion measuring 14 × 11 cm involving more than 180° of the forearm, which presents with fetid, yellowish-green bloody and purulent discharge. The lesions are indurated, with irregular, well-defined borders, on xerotic skin with photodamage. Extensive soft tissue edema extending to the mid-third of the arm is associated with limited extension of the limb and restricted wrist mobility. The ipsilateral axilla is negative.
Skin biopsies were taken for histopathological study. Histological sections of the left upper limb show the formation of keratin pearls and areas of ulceration. Underlying this is a solid neoplasm composed of medium-sized cells with abundant cytoplasm and intercellular bridges; vesicular nuclei, some with prominent nucleoli and others hyperchromatic and pleomorphic. Extensive areas of necrosis and granulation tissue are evident, with perineural and lymphovascular invasion.
Sections of nodular cutaneous lesions show loss of epidermal continuity with a surface covered by granulation tissue. The epidermis shows hyperkeratosis and parakeratosis. Multiple granulomas with multinucleated giant cells phagocytizing fumagoid cells (Medlar bodies) are identified in the dermis, findings consistent with
chromoblastomycosis.
The microbiological study reported abundant pure culture of Candida parapsilosis. The radiograph of the left upper extremity showed extensive swelling and thickening of the soft tissues of the forearm, consistent with an advanced inflammatory process, without identifying lytic or blastic bone lesions.
Based on the histological results, treatment by oncological surgery was evaluated, and radical surgery was chosen due to soft tissue involvement, functional impairment, and neurological deficits. Limb preservation was not possible, and external beam radiotherapy would offer little benefit due to the tumor's size.
Due to extensive limb involvement and associated tissue destruction, a transhumeral amputation was performed. Multiple ulcerated nodular lesions, confluent into scaly plaques and erosions, with a peripheral grayish halo, were identified throughout the skin surrounding the neoplasm. Dissection revealed a tumor with a depth of invasion
of 3.5 cm, involving the subcutaneous tissue and reaching the fascia of the extensor muscles of the fingers.
