[Hidradenocarcinoma arising from pre-existing hidradenoma]

Malignant Transformation of Retroauricular Hidradenoma in Hidradenocarcinoma in a Nine-Year-Old Patient: A Case Report

Hidradenocarcinoma, a rare malignant entity that derives from sweat glands, is especially rare in the pediatric population. The treatment of choice is surgery. Radiation therapy is used only in selected patients. Chemotherapy is not used extensively because its effectiveness has not been demonstrated yet. This case report describes a nine-year-old female patient who presented in 2018 with a vegetative lesion in the right parietal region. After excisional surgery, pathology confirmed that the lesion was a benign hidradenoma. However, the lesion recurred six months later, and subsequent surgery revealed nodular hidradenoma with positive margins. In July 2019, a new heterogenous lesion appeared in the right retroauricular region, which was surgically removed. The pathology report found possible malignant characteristics, and the patient was referred to our hospital where she was diagnosed with poorly differentiated right retroauricular carcinoma with infiltrative and perineural permeation, along with homolateral lymph node metastasis. It was histologically compatible with a hidradenocarcinoma. The patient underwent a wide-margin excision and homolateral total cervical lymphadenectomy, followed by adjuvant radiotherapy. The last follow-up MRI was negative for disease recurrence or metastasis; however, a slow-growing node on the left jugular chain (level II) was noted. The patient is on regular follow-ups to monitor disease status and treatment-related adverse events. This case highlights the challenges of diagnosing and treating hidradenocarcinoma, a rare malignancy that requires aggressive management with a multidisciplinary approach. More robust clinical evidence is needed to define the best treatment approach for these aggressive tumors.

Hidradenocarcinoma of the Abdominal Wall Treated With Wide Surgical Excision and Adjuvant Radiotherapy

Hidradenocarcinomas are rare malignant sweat gland tumors that typically arise in the head and neck area. To the best of our knowledge, this is the only reported instance of hidradenocarcinoma of the abdominal wall as well as the first case arising from a region of prior trauma. A 72-year-old female presented with a left abdominal wall lesion, which she had first noticed after an injury to the area. Initially, the lesion remained stable in size, after which it became mildly pruritic, progressive in size, and expressive of a clear, non-odorous discharge. Imaging demonstrated a heterogeneous cystic density. Surgical pathology revealed a malignant dermal adnexal neoplasm composed of pleomorphic polygonal cells and focal intracytoplasmic lumina lined by eosinophilic cuticles, as well as areas of ductal differentiation, apocrine differentiation, and mucinous metaplasia. Surgical excision of the mass was performed, followed by adjuvant external beam radiotherapy (EBRT). The patient had no long-term toxicities or clinical evidence of local disease recurrence as of one year post-surgery and six months post-EBRT. Early diagnosis and treatment are essential to improving outcomes in patients with hidradenocarcinomas. Frequent follow-up is equally important, as these tumors have high recurrence rates.

An Unusual Case of Lower Extremity Clear Cell Hidradenocarcinoma

Hidradenocarcinoma (HC) is a rare malignant sweat gland tumor with metastatic potential primarily located in the head, neck, and trunk. We present an unusual case of a large lower extremity Clear Cell HC managed with surgical resection and adjuvant locoregional radiation after excluding lymph node involvement.

[Hidradenocarcinoma of the heel associated with inguinal metastases]

BACKGROUND

Hidradenocarcinoma is a rare malignant tumour involving the sweat glands. It classically arises de novo, only rarely resulting from pre-existing hidradenoma. The literature contains few reports of lymph node metastasis in this tumour. We report a case of a patient with hidradenocarcinoma of the heel associated with inguinal node metastases.

PATIENTS AND METHODS

We report the case of a 64-year-old patient with a history of chronic smoking, who in the last two years developed a painless nodule in his right heel, with no prior injury, and which gradually increased in size to become an ulcerated tumour. Physical examination revealed a rounded tumour mass, ulcerated in the centre, and associated with multiple inguinal adenopathies. Histological and immunohistochemical examination was suggestive of hidradenocarcinoma. The patient had undergone extensive local excision with inguinal lymphadenectomy. Histological examination showed infiltration of lymph nodes by the tumour with capsular rupture. Radiotherapy was subsequently given. The outcome was good without recurrence after 34 months of follow-up.

DISCUSSION

Hidradenocarcinoma is a rare malignant tumour. Diagnosis is based on histological and immunohistochemical examination. However, hidradenocarcinoma may on occasion be difficult to differentiate from hidradenoma, a benign tumour, hence the interest of complete surgical resection with safety margins even in the absence of cytological malignancy. Local recurrences are common. The occurrence of lymph node metastasis during hidradenocarcinoma has been described only rarely in the literature. Such metastases usually occur after tumour resection. The specific features of our case are the rarity of lymph node metastases in hidradenocarcinoma coupled with the fact that these metastases were discovered upon diagnosis of the primary tumour.

Challenges in the diagnosis of cutaneous adnexal tumours

The diagnosis of cutaneous adnexal neoplasms, a heterogeneous group of entities, is often perceived by practising pathologists as challenging. A systematic approach to diagnosis is necessary for classification of these lesions, which establishes the tumour differentiation (follicular, sebaceous, sweat gland or apocrine) and evaluates histological features differentiating between benign and malignant entities. Consideration of clinical history is a necessary adjunct in evaluation of the adnexal neoplasm, as characteristic anatomical sites are described for many adnexal lesions. In some instances, immunohistochemical studies may also be employed to aid the diagnosis. The differential diagnosis between primary cutaneous adnexal neoplasms and cutaneous metastases from visceral tumours may also be difficult. Clinical, radiological, histological and immunohistochemical characteristics will be further discussed, considering that the correct diagnosis has a significant impact on the patient's management and prognosis.

Current management approach to hidradenocarcinoma: a comprehensive review of the literature

Hidradenocarcinoma is a rare malignant adnexal tumour which arises from the intradermal duct of eccrine sweat glands. The head and neck are the most common sites of hidradenocarcinoma, but rarely it can occur on the extremities. As it is an aggressive tumour, regional lymph nodes and distant viscera are the most common sites of metastasis. Diagnosis is confirmed by histopathology and immunohistochemistry. Hidradenocarcinoma should be differentiated from benign and malignant adnexal tumours. Being an aggressive and rare tumour, no uniform treatment guidelines have been documented so far for metastatic hidradenocarcinoma. Wide local excision is the mainstay of the treatment, but because of high local recurrence, radiotherapy in a dose of 50Gy–70Gy and/or 5-fluorouracil and capecitabine-based combination chemotherapy may be given to further improve local control. Other treatment strategies are targeted therapies like trastuzumab, EGFR inhibitors, PI3K/Akt/mTOR pathway inhibitors, hormonal agents like antiandrogens, electrochemotherapy, or clinical trials.

Atypical fibroxanthoma: new insights

Atypical fibroxanthoma (AFX) is an ultraviolet radiation-associated dermal neoplasm. To address the clinicopathologic and molecular features of this particular neoplasm. The author conducted a literature review using PubMed searching for articles relating to AFX. AFX usually appears as a rapidly growing nodular or nodulo-ulcerative lesion. It occurs on sun-exposed skin of elderly peoples. AFX may be composed predominantly of pleomorphic, spindle, epithelioid cells, or admixture of these cells. The differential diagnosis of AFX includes pleomorphic dermal sarcoma, squamous cell carcinoma, malignant melanoma and leiomyosarcoma. Several observations favor a mesenchymal origin for AFX. These reviews address the clinicopathologic features, molecular pathology, prognosis and treatment of this neoplasm.

Radiotherapy on hidradenocarcinoma

Context:

Clear cell Hidradenocarcinoma is a rare carcinoma arising from sweat glands. It is an aggressive tumor that most metastasizes to regional lymph nodes and distant viscera; surgery with safe margins is the mainstay of treatment.

Case Report:

We report a case of 68-year-old woman who presented with an invasive clear cell hidradenocarcinoma situated in the left parotid area which recurred 5 months after surgery, this recurrence was managed successfully by high-dose irradiation of the tumor bed (66 Gy) and regional lymphatic chains (50 Gy), after a follow-up of more than 15 months, the patient is in good local control without significant toxicity.

Conclusion:

Post operative radiotherapy allows better local control and should be mandatory when histological features predictive of recurrence are present: positive margins, histology poorly differentiated, perineural invasion, vascular and lymphatic invasion, lymph node involvement, and extracapsular spread.