Orthopedics & Rheumatology

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Received: January 01, 1970 | Published: ,

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Abstract

The aim of this article is to highlight the importance of Eccrine Spiradenoma (ES) in the differential diagnosis of chronic soft tissue lesions of the foot. These include a broad spectrum of non-neoplasm lesions, as well as benign and malignant neoplasms. We report a case of a 61 years old man, presenting a slow growing mass on the dorsum of his left hallux, appearing 10 years earlier. On examination it was a 4 cm tumefaction, not painful neither tender, with rubber consistence and no adherence to deep structures. X-ray images showed no bone alterations and ultrasound examination showed a cystic structure rendering synovial cyst a probable diagnosis. He was proposed for surgical excision in order to be able to use shoes without discomfort. The patient was operated under general anaesthesia and the excisional sample was sent to anatomopathological examination, revealing an Eccrine Spiradenoma with an unusual cystic pattern. ES was initially defined as a clinical pathology entity by Kersting and Helwig (1956). It is recognized as a rare skin adnexal neoplasm, exceptionally rare on foot, justifying the importance of this clinical case report. The rate of ES malignant transformation is low, but quite aggressive when it occurs (developing metastasis in about 50%), which makes early definitive diagnosis of major concern. Treatment of ES has not yet been well established; however surgical excision remains the gold standard option, with low rates of recurrence documented. ES is a rare soft tissue benign neoplasm that should be considered in the differential diagnosis of chronic soft tissue lesions of the foot and has a generally good prognosis after surgical excision.

Introduction

Case report

We report a case of a 61 years old man, presenting a slow growing mass on the dorsum of his left hallux, appearing 10 years earlier. He had previous history of an attempted drainage with no liquid content outflow. On examination it was a 4-cm tumefaction (Figures 1)(Figure 2), not painful neither tender, with rubber consistence and no adherence to deep structures. X-ray images showed no bone alterations and ultrasound examination showed a cystic structure rendering synovial cyst a probable diagnosis. He was proposed for surgical excision in order to be able to use shoes without discomfort.

Figure 1 Foot lesion at presentation.

Figure 2 Foot lesion at presentation.

Procedure

The patient was operated under general anaesthesia and the excisional sample (Figures 3)(Figure 4) was sent to anatomopathological examination. Macroscopy: it was 21g weight and measuring 5x4.2x2.5-cm; multi-cystic appearance, with the biggest cyst having 3.4-cm of diameter, with 1mm wall thickness.

Figure 3 Dissecting the lesion.

Figure 4 Excisional sample.

Diagnosis & histopathology

Diagnosis was a complete margin excision Eccrine Spiradenoma with an unusual cystic pattern (Figures 5)(Figure 6) having a luminal cell population, CK8/18 positive (Figure 7), and a basal and myoepithelial cells population, p63 positive (Figure 8).

Figure 5 Eccrine Spiradenoma with an unusual cystic pattern. (H&E stain, ob. x2.5).

Figure 6 Eccrine spiradenoma is a nodular tumor, constituted by small cells, with lymphoid infiltrate (H&Estain, ob. x20).

Figure 7 CK8/18 positive (ob. x20).

Figure 8 p63 positive (ob. x20).

Discussion

ES was initially defined as a clinical pathology entity by Kersting and Helwig in 1956 as a tumour of the sweat gland from eccrine differentiation. The classification of spiradenoma as eccrine in origin is so entrenched in the literature that most textbooks list spiradenoma as “eccrine spiradenoma” in their index.³ Nowadays we know that spiradenoma is not an eccrine tumor; rather it is a follicular tumour, asserting that this adnexal neoplasm derives from the hair follicle bulge and represent the least differentiated follicular tumours.⁴ It is recognized as a rare skin adnexal neoplasm, exceptionally rare on foot, justifying the importance of this clinical case report. ES is able to be present on any part of the body,⁵ with approximately 20% of the cases occurring in the extremities. ⁶Lesions usually manifest as solitary, 1-cm-diameter nodules on the upper half of the ventral side of the body; but may also present as multiple tumours. ES can appear at any age, commonly arises in persons aged 15-35 years, and no gender predominance has been reported. While textbooks say spiradenomas are painful, this was not reported in most patients of one study.⁷ The rate of ES malignant transformation is low, but quite aggressive when it occurs (developing metastasis in about 50%), and can occur within a long-standing lesion⁸which makes early definitive diagnosis of major concern. Treatment of ES has not yet been well established; however surgical excision remains the gold standard option, with low rates of recurrence documented.⁹

Conclusion

ES is a rare soft tissue benign neoplasm that should be considered in the differential diagnosis of chronic soft tissue lesions of the foot and has a generally good prognosis after surgical excision.