BASOSQUAMOUS CARCINOMA: A RARE CASE OF EAR METASTATSIS IN A 13 YEARS-OLD

Abstract

BASOSQUAMOUS CARCINOMA REMAINS A RARE FINDING IN CHILDREN AND, IS OFTEN, MISINTERPRETED AS A SUQAMOUS CARCINOMA. [...]THIS WORK IS INTENDED TO FOCUS THE IMPORTANCE OF THIS DISEASE FOR PATHOLOGISTS WHO INVESTIGATE CHILD DERMATOPATHOLOGY, REGARDING THIS MATTER. Clinically, BSQC metastasis has no specific features, while the biopsy is the only way to figure out the final diagnosis. [...]the histopathological diagnosis might be very problematic, because the growth is very slow. A single institution retrospective analysis of basosquamous carcinoma of the head and neck, J Clin Oncol., 2006; 24:15530; Zamfir-Radu IONESCU1 1 PhD, MD of Pathology, Head of the Pathology Department of Pediatric Hospital, Pitesti, Arges, , Romania, dr.raduionescu@yahoo.

Headnote

ABSTRACT:

WE PRESENT THE CASE OF A 13-YEARS OLD FEMALE CHILD, WITH A NODULAR TUMOR ON THE EAR LOBE, RESECTED AND INVESTIGATED IN THE PEDIATRIC HOSPITAL OF PITESTI, ROMANIA. THE INITIAL CLINICAL DIAGNOSIS WAS OF A SEBACOUS CYST, BUT, AFTER CLOSER INSPECTION AT THE MICROSCOPE, WE DETECTED THE PRESENCE OF SQUAMOID PROLIFERATIONS, WITH KERATINISATION AND BASALOID FEATURES, CONCLUDING THE DIAGNOSIS AS A METASTASIS WITH BASOSQUAMOUS CARCINOMA ORIGIN. BASOSQUAMOUS CARCINOMA REMAINS A RARE FINDING IN CHILDREN AND, IS OFTEN, MISINTERPRETED AS A SUQAMOUS CARCINOMA. THEREFORE, THIS WORK IS INTENDED TO FOCUS THE IMPORTANCE OF THIS DISEASE FOR PATHOLOGISTS WHO INVESTIGATE CHILD DERMATOPATHOLOGY, REGARDING THIS MATTER.

KEY WORDS: BAZOCELLULAR CARCINOMA, BASOSQUAMOUS CARCINOMA, METATYPICAL CARCINOMA, COLLISION TUMOR

INTRODUCTION

Basal cell carcinoma, clinically, may present on sun-exposed skin areas, particularly on face, being more frequent in white adults. Occurrence in young adults, other than in the context of nevus sebaceous, nevoid basal cell carcinoma syndrome, or Rombo syndrome remains exceptional. However, in children, Gorlin syndrome is characterized by basal cell carcinomas, with odontogenic jaw cysts, pitted depression of the hands and feet, osseous anomalies, a broad nasal root and hypertelorism. The indicence of all basosquamous carcinoma (BSQC) remains at 1-2% of all dermatological malignancy cases, having different synonyms: metatypical carcinoma, basaloid squamous carcinoma, or collision tumor, if both components (squamous and basal cell) are even. Futhermore, a BSQC metastasis presents itself as well delimited formation, although its incidence is lower than 5% in children younger than 20 years old2. Clinically, BSQC metastasis has no specific features, while the biopsy is the only way to figure out the final diagnosis. Thus, the histopathological diagnosis might be very problematic, because the growth is very slow. There might be encountered areas of basocellular and squamous carcinoma. The cells of basal component are larger, with pale cytoplasm, with areas of squamoid features that have abundant eosinophilic cytoplasm. Frequently, it might be visible another area of cells having transitional features intermingled in between both components. Not rarely, characteristic peripheral pallisading and stromal retraction remain inconspicuous. The diagnosis must well document the superposition of basal cell carcinoma with the squamous one3.

CASE REPORT

The differential diagnosis encompassed lymphoepithelioma-like carcinoma, metastatic ameloblastic carcinoma and Ewing sarcoma. These possible situations were taken into account as the localization of metastasis was more frequent in head and neck regions. However, pathological and imagery criteria were not met for any of these tumors. The final diagnosis was that of a metastatic bazosquamous carcinoma with local invasion of the left ear lobe.

We present the case of a 13 years old female child, having a good health status, with no other complaints or symptoms, except for a mass on the left ear lobe, that enlarged within a 6 weeks duration to 1,5/0,7 cm. The rest of clinical examination and imagistics proved no obvious or worrisome lesions. Laboratory routine blood tests proved negative for all counts. The ear-nose-throat department in our hospital referred the case for resection within 2-4 mm margins for esthetical reasons. We received the tissue sample in our Pathology Department, fixed in 10% buffered formalin. It presented as a well delineated, nodular mass, with a gritty aspect, having intermingled white to brown areas and a general non-homogenous aspect (fig nr. 1).

After tissue processing in successive alcohol concentrations (70, 80 and 96 degrees), paraffin embedding and sectioning with haematoxilin and eosin staining, we found definite squamous areas with ortho- and parakeratin forming pearls with basaloid features, without peripheral pallisading and with pseudo-stromal retraction (fig. nr. 2). These carcinomatous entities were detected inside dilated, ectatic blood vessels encircled by a desmoplastic, lymphoplasmocytic infiltrated fibrous strands, as the metastatic cells already invaded within the local perivascular connective tissues (fig. nr. 3). In transitional areas, more visible towards the basaloid areas, squamous morules were detected, thus proving the tendency for squamous differentiation. Atypical mitoses were found exclusively in basaloid areas of the BSQC, approximately 5 to 6 mitoses per field.

The case was reviewed interdisciplinary - pediatric surgeon, ear-nose-throat senior specialist, pathologist - for oncological treatment in a regional specialized department for similar pediatric cases.

DISCUSSION

The differential diagnosis encompassed lymphoepithelioma-like carcinoma, metastatic ameloblastic carcinoma and Ewing sarcoma. These possible situations were taken into account as the localization of metastasis was more frequent in head and neck regions. However, pathological and imagery criteria were not met for any of these tumors. The final diagnosis was that of a metastatic bazosquamous carcinoma with local invasion of the left ear lobe. For definitive diagnosis, immunohistochemistry is necessary, although it has limited value. Representative paraffin embedded tissue samples should reserved for immunostaining with AE1/AE3, bcl-2, TGF-A, Ver-EP4, p53 molecular antibodies. With this kind of approach, it might be best visible the transitional area between the two components of the BSQC4 The optimal way to observe this kind of transitional cellular effect is with Ber-EP4, who is detected in all basocellular tumors. This might indicate the presence of a pluipotential cell capable of differentiation trough a genetical mutation, causing frequent appearance of metastasis in such a young age5.

Main therapy is represented by resectional surgery with security margins and chemotherapy, although this kind of tumor remains unresponsive, especially with oncological radiotherapy and pharmacological approach, in metastastic disease. In chemotherapy, we might use doxorubicin, cisplatin, fluorouracil in varying cycles, depending of CT volumetric response of the main tumor6.

CONCLUSIONS

This collision tumor or BSQC remains with an overall low frequency among all cutaneous malignancies, in children; it has origins in basal cells of the epidermis, and a high potential for metastasing or invasion, especially because of the squamous features.

Footnote

2 O. Karatas Silistreli, M. Ayhan, Z. Aytug. Periocular metatypical cell carcinoma: Clinicopathologic correlation, management, and follow-up in 35 patients, J Plast Reconstr Aesthet Surg, 2006; 59:1280-1287;

3 R.C. Martin, M.J. Edwards, T.G. Cawte. Basosquamous carcinoma: Analysis of prognostic factors influencing recurrence, Cancer.,2000; 88:1365-1369;

4 B. Lennox, A. Wells. Differentiation in the rodent ulcer group of tumors, Br J Cancer, 1951, 5:195 -212;

5 M.S. Jones, K.F. Helm, M.E. Maloney; The immunohistochemical characteristic of the basosquamous cell carcinoma, Dermatol Surg., 1997; 23:181-184;

6 P. Clement, J. Verheezen, S. Nuyts. A single institution retrospective analysis of basosquamous carcinoma of the head and neck, J Clin Oncol., 2006; 24:15530;

References

REFERENCES

1. O. Karatas Silistreli, M. Ayhan, Z. Aytug. Periocular metatypical cell carcinoma: Clinicopathologic correlation, management, and follow-up in 35 patients, J Plast Reconstr Aesthet Surg, 2006; 59:1280-1287;

2. R.C. Martin, M.J. Edwards, T.G. Cawte. Basosquamous carcinoma: Analysis of prognostic factors influencing recurrence, Cancer.,2000; 88:1365-1369;

3. B. Lennox, A. Wells. Differentiation in the rodent ulcer group of tumors, Br J Cancer, 1951, 5:195-212;

4. M.S. Jones, K.F. Helm, M.E. Maloney; The immunohistochemical characteristic of the basosquamous cell carcinoma, Dermatol Surg., 1997; 23:181-184;

5. P. Clement, J. Verheezen, S. Nuyts. A single institution retrospective analysis of basosquamous carcinoma of the head and neck, J Clin Oncol., 2006; 24:15530;