CARTA AL DIRECTOR

Benign lingual fibrous histiocytoma. An uncommon finding

Histiocitoma fibroso Benigno lingual. Un hallazgo infrecuente

Dear Editor,

On occasions, we encounter unexpected findings in clinical practice. The tongue is an organ accessible to direct clinical examination, which is why lingual pathology usually is diagnosed early (except for symptoms of the lingual base). This makes it possible to perform exeresis and a histologic study of the lesions, which in most cases end up being classified into a relatively small group of pathologies, mainly epithelial. The finding of soft tissue lesions in this location can be considered infrequent. If fibrohistiocytic lesions of the benign fibrous histiocytoma type are involved, few cases have been reported in the literature (1,2).

We wish to present in this letter the case of a 50-yearold man who was seen in the clinic for an excrescent lesion on the tip of the tongue. The clinical opinion was lingual papilloma. Surgical exeresis was performed and the piece was sent for histopathologic study.

The lesion was semi-spherical and of firm consistency with a brownish tone. It measured 0.4 cm in its maximum diameter. Histologic study of the specimen allowed the identification of spindle-cell lesions with a focal storiform pattern in which ramified fibrous tracts were observed in relation to groups of spindle cells without nuclear atypia that acquired an epithelioid surface morphology, where they took on histiocytic characteristics that were confirmed by the immunohistochemical marker CD68. The CD34 marker showed the vascular pattern of the lesion, being negative in the proliferating cell population. It reached the interface with striate muscle with infiltrative margins without penetrating it. The ulcerated epithelium exhibited intense acanthocytosis, exocytosis, and parakeratosis. With this information the diagnosis of benign fibrous histiocytoma was made (Figs. 1 and 2).

As previously commented, it is a frequent skin lesion but it is extremely uncommon in the tongue and there is little or no experience with its management in this location. In view of its cutaneous behavior, recurrence can be expected, although it can be minimized with proper surgical exeresis. In our case, the muscular plane was reached, but the margins of the lesion were intact. The lesion has not recurred, although the follow-up period is short (a few months). The cases cited in the literature to which we have had access have been judged clinically as pyogenous granulomas of slow and progressive growth. Surgical exeresis was the treatment used in every case. As far as the histology, two cases were identified as epithelioid histiocytoma (3,4) and one as atypical fibrous histiocytoma (5). Cases of malignant fibrous histiocytoma of lingual location are more common in the literature, whether or not associated with regional radiotherapy (6). However, it should be noted that it is an undifferentiated malignant neoplasm in a group in which heterogeneous neoplasms have been included traditionally without clear signs of differentiation.

Analyzing our case, we observed bidirectional growth of the lesion in depth, without reaching the striate muscle, and toward the epithelial plane. The epitheliumlamina propria interface is not involved, a characteristic that can be considered typical of the mucosal lesions as opposed to more common skin locations. The origin of the proliferating population is not absolutely clear, although we cannot rule out the possibility of lesions reactive to previous trauma. Our case is the only one of the tip of the tongue.

Francisco Javier Torres Gómez¹, Eusebio Torres Carranza², Sandra Moreno Corral (TEAP)³

¹Unidad de Anatomía Patológica. Hospital de Alta Resolución de Utrera
²Servicio de Cirugía Oral y Maxilofacial. Hospital Universitario Virgen del Rocío
³Unidad de Anatomía Patológica. Hospital de Alta Resolución de Utrera

References

1. Thompson S, Shear M. Fibrous histiocytomas of the oral and maxillofacial regions. J Oral Pathol 1984;13:282.        [ Links ]

2. Regezi J, Zarbo R, Tomich C. Immunoprofile of benign and malignant fibrohistiocytic tumors. J Oral Pathol 1987;16:260.        [ Links ]

3. Rawal YB, Kalmar JR, Shumway B, Mallory SR. Presentation of an epithelioid cell histiocytoma on the ventral tongue. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2005;100:75-83.        [ Links ]

4. Takimoto T, Ishikawa S, Umeda R. Fibrous histiocytoma of the tongue base. Auris Nasus Larynx 1990;16:233-36.        [ Links ]

5. Velez Torres R, Owen LG, Hodge SJ, McMurray GT, Roe E. Atypical fibrous histiocytoma of the tongue. A case report. Int J Dermatol 1986;25 :656-57.        [ Links ]

6. Lin SK, How SW, Wang JT, Liu BY, Chang CP. Oral post-radiation malignant fibrous histiocytoma. A clinicopathological study. Oral Pathol Med 1994;23: 324-29.        [ Links ]