Indian Journal of Dermatology
: 2021  |  Volume : 66  |  Issue : 3  |  Page : 330-

Skin biopsy in the diagnosis of a rare case of sinonasal undifferentiated carcinoma

Rita Bouceiro-Mendes1, Maria Mendonça-Sanches1, Luís Soares-de-Almeida2,  
1 From the Department of Dermatology, Hospital de Santa Maria, Lisbon, Portugal
2 From the Department of Dermatology, Hospital de Santa Maria, Lisbon; Department of Clinical Immunology, Pathology and Dermatology, Molecular Medicine Institute, Lisbon Medical School, Portugal

Correspondence Address:
Rita Bouceiro-Mendes
From the Department of Dermatology, Hospital de Santa Maria, Lisbon

How to cite this article:
Bouceiro-Mendes R, Mendonça-Sanches M, Soares-de-Almeida L. Skin biopsy in the diagnosis of a rare case of sinonasal undifferentiated carcinoma.Indian J Dermatol 2021;66:330-330

How to cite this URL:
Bouceiro-Mendes R, Mendonça-Sanches M, Soares-de-Almeida L. Skin biopsy in the diagnosis of a rare case of sinonasal undifferentiated carcinoma. Indian J Dermatol [serial online] 2021 [cited 2022 May 25 ];66:330-330
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Full Text


An 82-year-old man was seen in our outpatient clinic with a two-week history of skin nodules along with weight loss (10 kg in three months), anorexia, and fatigue. Apart from being a heavy smoker (120 pack-year), his past medical history was unremarkable. On clinical examination, the patient was clearly weak and had multiple subcutaneous nodules on the thorax and dorsum [Figure 1] as well as generalized adenopathies.{Figure 1}

Routine blood tests identified a normocytic and normochromic anemia and elevation of lactate dehydrogenase (973U/L, N < 250U/L). Epstein–Barr virus serologies were negative. Histologic examination of the skin biopsy [Figure 2] showed dermis infiltration by blue epithelioid and pleomorphic cells grouped in strands and dissecting the collagen fibers. Increased mitotic activity and cells within the lymphatic vessels were observed. Immunohistochemistry studies stained positive for cytokeratin 7, cytokeratin AE1/AE3, and epithelial membrane antigen (EMA). Staining for S-100 protein, vimentin, cytokeratin 20, TIF-1, GATA-3, and neuroendocrine markers was negative [Figure 3]. All these features were consistent with the diagnosis of sinonasal undifferentiated carcinoma (SNUC). Further work-up showed multiple hepatic, splenic, adrenal, and retroperitoneal secondary lesions as well as disseminated nodal involvement. Head computerized tomography revealed secondary lesions in the cerebellum and a bilateral nasopharyngeal mass. The patient rapidly deteriorated his condition dying one month after admission. Only palliative measures were applied.{Figure 2}{Figure 3}

SNUC is a rare and highly aggressive form of head and neck cancer that mainly affects older men.[1],[2] Its etiology is unknown and, in contrast to nasopharyngeal carcinoma, it is not associated with Epstein–Barr virus infection. An association with cigarette smoking has, however, been described.[1]

Skin metastases are an unusual manifestation.[1],[3] The histological features observed in our biopsy match those described for SNUC consisting of polygonal, round-to-oval cells with a variable size, and hyperchromatic nuclei with varied growth patterns and no evidence of squamous or glandular differentiation.[1],[2] Lymphovascular invasion and neurotropism are often present.[1],[4] Immunohistochemical markers are crucial because this undifferentiated neoplasm[1–3] is immunohistochemically distinct from other sinonasal malignancies, such as melanoma (S100+, CK−), nasopharyngeal carcinoma (CK7−), olfactory neuroblastoma (S100+, synaptophysin+, chromogranin+), and neuroendocrine carcinoma (synaptophysin+, chromogranin+/−). Other types of cancer with possible metastases to the skin, including Merkel cell carcinoma (CK20+, synaptophysin+, chromogranin+) and metastatic tumors from lung (TIF-1+) and breast (GATA-3+) were excluded.[1],[2],[5] Given the metastatic involvement and the refusal in directed treatment modalities, a biopsy of the primary lesion was not made.

Although aggressive multimodal therapy is considered the best therapeutic option, there is no standard of care[2],[4] and long-term outcomes are poor.[4] Surgical resection combined with local radiotherapy and chemotherapy is the recommended strategy.[1],[2] However, one-third of the patients presents with extensive disease and surgical resection is not feasible. In these cases, radiotherapy with or without chemotherapy should be considered.[1],[2]

From the best of our knowledge, this is the first described case of an SNUC with cutaneous metastases at the time of diagnosis showing that this rare and aggressive tumor may solely manifest with cutaneous lesions, rendering the skin as a fundamental piece to its diagnosis.

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.

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Conflicts of interest

There are no conflicts of interest.


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