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WSU Medical School

Training Level

Medical Student


Wayne State University


Abstract: Low-grade non-intestinal type adenocarcinomas are rare tumors that arise from the surface epithelium of the sinonasal tract. They frequently involve the ethmoid sinus, the nasal cavity, and the maxillary sinus. These tumors present at a mean age range of 37-53 years with various non-specific symptoms including nasal obstruction and epistaxis. We report the first case of a low-grade non-intestinal type sinonasal-adenocarcinoma of the ethmoid sinus presenting with persistent unilateral epiphora.

Case Presentation: A 67-year-old man presented with complaints of bloody tearing and right medial canthus swelling for several months. Examination of the area revealed a small bump beneath the skin which burst with a green mucopurulent discharge on gentle palpation. Computed tomography (CT) scans revealed a large growth in the ethmoid sinus invading into the right medial orbit and extending into the maxilla. Histopathology (H&E) demonstrated a cribriform pattern, moderately graded nuclei, and eosinophilia consistent with non-intestinal type sinonasal adenocarcinoma. The patient underwent orbital exenteration and large sinus resection.

Discussion: Cancers of the paranasal sinuses are extremely uncommon and account for just 1% of all human cancers. Low-grade non-intestinal type adenocarcinoma is an extremely rare subtype that has only been reported a handful of times. Synonyms in the literature include terminal tubulus adenocarcinoma, sinonasal tubulopapillary low-grade adenocarcinoma, and sinonasal seromucinous adenocarcinoma. Microscopic analysis is key for differentiation of this tumor type from other similar sinonasal malignancies as well as for prognostication purposes. Histologically, non-ITAC is recognized by its trabecular, cribaform, or papillary growth pattern and the single layer of uniform columnar or cuboidal cells that line its glands. Pleomorphic nuclei and mitotic figures are rarely seen in this subtype. Immunohistochemically, non-ITAC is characterized by positive CK7 staining and/or negative CDX-2 and CK-20 staining. Differential diagnoses to consider include intestinal type adenocarcinoma (ITAC), acinic cell carcinoma, and oncocytic Schneiderian papilloma. ITAC is an aggressive malignancy that is differentiated from non-ITAC on the basis of its resemblance to the mucosa found in the small and large intestine, its high-grade histologic appearance, and cellular expression of CDX-2. Distinguishing the two tumors types is of crucial clinical importance given that low-grade non-ITAC has not, to date, displayed metastatic behavior while several instances of low-grade ITAC metastases have been reported. Rarely, non-intestinal type adenocarcinoma may be confused with oncocytic Schneiderian papillomas. However, the epithelium of oncocytic Schneiderian papillomas are multilayered and lack glandular lumina. The presenting clinical symptoms of non-ITAC vary, however the most common reported symptoms are nasal obstruction and epistaxis. In our case, the patient presented with persistent unilateral epiphora which has not, to date, been reported in association with this tumor subtype. The mainstay in treatment of low-grade non-ITAC includes surgery followed by radiation therapy. Overall, the prognosis of patients with non-ITAC is good and rarely does death occur due to the disease.

Presentation Date


Adenocarcinoma of the Ethmoid Sinus Presenting with Epiphora