Brain Pathology Case of the Month - October 2012

Contributed by Markus J. Hofer MD1, Jochen Rohlfs MD2, Afshin Teymoortash MD3, Axel Pagenstecher MD1
Departments of 1Neuropathology, 2Neurosurgery and 3Otolaryngology, Head and Neck Surgery, Philipps University Marburg, Germany


CLINICAL HISTORY

A 62-year old female patient presented with constricted nasal breathing on the right side, disorder of smell and anosmia for the past six months. She had no epistaxis, rhinorrhea or loss of sensitivity in the face. Three months before presentation she suffered from a cold with swelling of the right eyelid that improved under conservative therapy. Physical examination revealed a glazed, bleeding tumor occupying the complete right nasal cavity and right nasopharynx and extending to the opposite site (Figure 1).

CT showed a tumor of the right sinuses with destruction of the right Lamina papyracea and the posterior wall of the right frontal sinus. MRT revealed a not clearly demarcated process of 5 x 5 x 4 cm of the right main nasal cavity that was of intermediate density on T1 weighted (Figure 2) and inhomogeneous hyperintensity on T2 weighted images (Figure 3). The process infiltrated the lamina cribrosa, right sphenoidal sinus, both frontal and ethmoidal sinuses causing dislocation of the right medial orbital wall but without infiltration of structures of the orbit. The process showed a close relationship to frontal central nervous system structures with potential infiltration of the meninges (Figure 2).

To obtain a diagnosis a rhinoscopy was performed and a reddish, partly soft, partly firm piece of tissue measuring 1.3 x 0.8 x 0.3 cm was sent to the Department of Neuropathology. Two weeks later tumor resection via a combined bifrontal transcranial skull base and endonasal approach was performed and multiple small tissue fragments measuring in total more than 8 x 6 x 2 cm were sent for pathological evaluation.

MICROSCOPIC PATHOLOGY - RHINOSCOPY

Paraffin sections showed a cellular tumor forming compact nests surrounded by fibrous tissue containing leukocytes (Figure 4). The tumor cells were moderately polymorphic and had a scant eosinophilic cytoplasm. Many nuclei contained prominent nucleoli (Figure 5) and occasional mitotic figures and numerous apoptotic cells were seen. Immunohistochemistry was positive for NCAM (CD56, Figure 6) and synaptophysin but negative for chromogranin. Some tumor cells expressed cytokeratin and weakly S100 protein (Figure 7). No expression of these markers was observed in most tumor cells and surrounding S100-positive sustentacular cells could not be identified (Figure 7). The Ki-67 labeling index was focally more than 30% (Figure 8). The specimen also included some local connective tissue and glands that appeared inconspicuous.

MICROSCOPIC PATHOLOGY - OPERATION

Light microscopy showed a cellular, lobulated tumor with intervening connective tissue identical to that observed in the initial sample. In addition the specimens contained local mucosa and glands. Comparable to the material from the first procedure, most glands had a regular architecture (Figure 9, right half). However, some glands had an atypical configuration but still discernible glandular structures and an intact appearing basal lamina (Figure 9, left half, and Figures 10, arrows). Here, the epithelium was multi-layered and cells had enlarged nuclei and prominent nucleoli resembling the tumor cells (Figures 10 and 11, arrows). In contrast to the normal appearing glandular cells (Figure 12, asterisks), the atypical cells expressed NCAM (Figure 12, arrows) but not cytokeratin.

FINAL DIAGNOSIS


International Society of Neuropathology