Malignant acanthosis nigricans as a paraneoplastic manifestation of metastatic breast cancer

F-18-FDG PET/CT findings of paraneoplastic dermatoses

Paraneoplastic dermatoses (PD) are defined as nonspecific skin disorders which are associated with internal neoplasms, but without direct association to primary tumors or metastases. Recognition of PD and the following surveillance may lead to the diagnosis of internal malignant neoplasms including early stage ones. Accurate imaging examinations in the following searching is essential in identifying the underlying neoplasms. Since whole-body 18-fluoro-2-deoxyglucose (F-18-FDG)-positron emission (PET)/computed tomography (CT) has been widely used in early diagnosis, staging of various malignant tumors, it may play a role for detection of underlying or occult malignant neoplasms in patients with PD. However, to date, only a few reports of FDG PET/CT findings of the associated neoplasms in PD patients have been cited in the literature. The present paper shows the cases of FDG-avid associated neoplasms in patients with PD in our 10-year experience in our institute, and reviews the well-known and/or relatively common PD and their associated neoplasms, and the previously reported cases of FDG-avid associated neoplasms in these patients.

Acanthosis Nigricans: An Updated Review

BACKGROUND

Early recognition of acanthosis nigricans is important because acanthosis nigricans can be a cutaneous manifestation of a variety of systemic disorders and, rarely, as a sign of internal malignancy.

OBJECTIVE

The purpose of this article is to familiarize pediatricians with the clinical manifestations, evaluation, diagnosis, and management of acanthosis nigricans.

METHODS

A search was conducted in November 2021in PubMed Clinical Queries using the key term "acanthosis nigricans". The search strategy included all clinical trials, observational studies, and reviews published within the past 10 years. Only papers published in the English literature were included in this review. The information retrieved from the above search was used in the compilation of the present article.

RESULTS

Acanthosis nigricans is characterized by symmetric, hyperpigmented, and velvety plaques with ill-defined borders, typically involving intertriginous areas. Obesity is the most common cause of acanthosis nigricans which is increasingly observed in obese children and adolescents and can serve as a cutaneous marker of insulin resistance. Early recognition of acanthosis nigricans is important because acanthosis nigricans can also be a cutaneous manifestation of a variety of systemic disorders and, rarely, as a sign of internal malignancy. This may consist of weight reduction, discontinuation of causative drugs, treatment of underlying endocrinopathy, or treatment of an underlying malignancy. For patients with isolated acanthosis nigricans and for those whose underlying cause is not amenable to treatment, treatment of the lesion may be considered for cosmetic reasons. Topical retinoids, vitamin D analogs, chemical peels, and other keratolytics are often used for the treatment of localized lesions. Seldom, systemic therapy such as oral retinoids may be considered for extensive or generalized acanthosis nigricans and acanthosis nigricans unresponsive to topical therapy. Other uncommon treatment modalities include dermabrasion, laser therapy, and surgical removal.

CONCLUSION

Although acanthosis nigricans is treatable, a complete cure is difficult to achieve. The underlying cause should be treated, if possible, to resolve and prevent the recurrence of acanthosis nigricans. The diagnosis is mainly clinical, based on the characteristic appearance (symmetrically distributed, hyperpigmented, velvety, papillomatous, hyperkeratotic plaques with ill-defined borders) and the typical sites (intertriginous areas, flexural area, and skin folds) of the lesions. The diagnosis might be difficult for lesions that have atypical morphology or are in an unusual location. Clinicians should be familiar with the clinical signs, evaluation, diagnosis, and therapy of acanthosis nigricans because of the link between it and underlying diseases.

Malignant acanthosis nigricans and diseases with extensive oral papillary hyperplasia

Oral papillary lesions represent a variety of developmental and neoplastic conditions. Early diagnoses of different papillary lesions are challenging for oral medicine specialists. Malignant acanthosis nigricans (MAN) is a rare cutaneous disorder and a potential marker of underlying hidden tumours. It is characterized by papillary lesions that always involve the oral mucosa. In oral medicine specialities, MAN is not well understood. When the early signs of MAN are extensive oral lesions and slight cutaneous pigmentation without obvious florid cutaneous papillomatosis, the diagnosis can be incorrect or delayed. Oral medicine specialists should ask affected patients to provide details of their medical history and conduct a timely systemic examination.

Paraneoplastic Conjunctival Acanthosis Nigricans: A Case Report

PURPOSE

To report a patient who presented with red eye and diffuse palpebral conjunctival thickening and papillary growth bilaterally.

METHODS

A 63-year-old woman with a medical history of stage IV adenocarcinoma of the lung with metastasis to the bone, the lung, and the lymph nodes presented with redness and irritation of both eyes for 3 months. The patient has been treated with topical corticosteroids for 3 weeks with no relief of symptoms.

RESULTS

Clinical examination and pathology report of conjunctival biopsy confirmed the diagnosis of conjunctival acanthosis nigricans.

CONCLUSIONS

Conjunctival acanthosis nigricans is a rare paraneoplastic condition that resembles papilloma and can present a challenge in diagnosis. When acanthosis nigricans occurs after the diagnosis of malignancy, it can be an indicator of progression of the underlying condition. The diagnosis of conjunctival acanthosis nigricans in a patient with no history of cancer should prompt clinicians for further malignancy workup.