A Case of a Coexisting Carcinosarcoma Ex Pleomorphic Adenoma With Langerhans Cell Histiocytosis in the Parotid Gland.

Carcinosarcoma ex pleomorphic adenoma is a rare malignant neoplasm, with most cases reported in the parotid gland. We herein report a case of a 75-year-old male referred to our hospital with a long-standing right parotid lesion that was treated in an outside hospital by a superficial parotidectomy. The patient reported a painful, rapidly enlarging mass following the excision. Histopathological examination showed the proliferation of malignant epithelial and mesenchymal elements with a solid sheet of Langerhans cells admixed with eosinophils. The Langerhans cells were reactive to CD1a and BRAF; hence, a diagnosis of carcinosarcoma ex pleomorphic adenoma with Langerhans cell histiocytosis was given. Complete clinical and radiographic workup showed no other organ involvement. The patient underwent total parotidectomy with adjuvant chemoradiation; however, the tumor progressed and showed lung metastasis. We herein report the first case of a concurrent Langerhans cell histiocytosis with associated carcinosarcoma ex pleomorphic adenoma.

Sinonasal Renal Cell-Like Adenocarcinoma: A Report of a Rare Entity With Emphasis on Its Association With Von Hippel Lindau Syndrome.

Sinonasal renal cell-like adenocarcinoma (SNRCLA) is a rare malignant sinonasal tumor with relatively indolent clinical course. Clinically, it could be asymptomatic or show non-specific symptoms such as epistaxis, nasal obstruction, or hyposmia. Diagnosis of the lesion is challenging, especially in small biopsies, and requires clinical, radiological, histopathological, and ancillary tests to characterize the lesion accurately. We herein report a case of a 41-year-old female with a nasal mass noted two years ago, which presented initially as frequent epistaxis from the right side. Histopathological examination revealed proliferation of clear cells associated with hemorrhagic background forming follicular and glandular structure and dense eosinophilic secretion. Tumor cells were diffusely positive for CK7, EMA, and inhibin, while they were negative for CK20, P63, CK 5/6, CD10, renal cell carcinoma (RCC), TTF1, PAX8, CEA, and GATA3. The proliferation index (KI67) was less than 5%. The diagnosis was consistent with SNRCLA. The patient has no recurrence and no symptoms after one year. Thus, our study reports a rare case of SNRCLA with a discussion of the histological features and its association with von Hippel Lindau syndrome.

SMARCB1-Deficient Sinonasal Carcinoma: Case Report and Review of the Literature.

BACKGROUND SMARCB1-deficient sinonasal carcinoma is a rare neoplasm with inactivation of the SWI/SNF complex, with an aggressive clinical course as most of the lesions present as advanced in pT3/T4 stages with frequent recurrence, and many patients succumb to the disease. Reported initially in 2014, the lesion has male predominance, with an age range of 19 to 89 years and predilection for the ethmoid sinus and nasal cavity. Histopathological findings show a proliferation of small- to medium-sized monomorphic basaloid cells with indistinctive cytoplasmic borders and round variably prominent nuclei with scattered cells that show rhabdoid morphology. Cytoplasmic vacuoles are common. It has similar morphological findings to a wide array of neoplasms in the sinonasal area. CASE REPORT We report a case of SMARCB1-deficient sinonasal carcinoma in a 30-year-old man referred to our hospital with a preliminary diagnosis of sinonasal adenocarcinoma, intestinal type. Computed tomography showed a huge destructive soft tissue mass in the left maxillary sinus, extended to involve the left nasal cavity with extension to the skull base and perineural spread along the foramen rotundum. Histological examination revealed a malignant basaloid neoplasm embedded in a myxoid stroma that showed loss of SMARCB1 stain. The patient was treated with induction chemotherapy using etoposide and cisplatin for disease control. CONCLUSIONS SMARCB1-deficient sinonasal carcinoma is a rare neoplasm with an aggressive clinical course and high-grade behavior despite having uniform cytological features. This poses complex diagnoses, especially in small biopsies. Incorporating morphological findings with ancillary tests is required to identify this high-grade malignancy.

Rosai-Dorfman Disease With Features of IgG4-Related Sclerosing Disease: A Case Report.

Rosai-Dorfman disease (RDD) is a rare condition characterized by the proliferation of non-Langerhans cell histiocytes that are associated with phagocytosed lymphocytes (emperipolesis). Clinically, it is classified into nodal, extra-nodal, neoplasia-associated RDD, and immune-related. Here, we present a case of a 65-year-old female who presented with facial pain following a dental procedure with no focal neurologic deficit. The MRI of the head and neck showed a well-defined lobulated soft tissue lesion with homogenous enhancement over the left cheek. Excision of the lesion was done, and the histopathological study reported extra-nodal RDD with features of IgG4-related sclerosing disease. The patient had no recurrence over the two years from the date of diagnosis.