Abstract

Post-operative inguinal neuralgia is an exceptional pathology despite the high frequency of surgery in this anatomical region. We report the case of a 62-year-old patient, initially managed for a painful right inguinal tumefaction mistakenly taken for a strangulated inguinal hernia. After hernia repair, the swelling recurred 2 months later, accompanied by intense neuralgic pain. The diagnosis of ilioinguinal nerve ligation was evoked or fibrosis of the surgical scar as a differential diagnosis, followed by corticosteroid infiltration with no pain improvement. The persistence of symptoms required an abdominal and pelvic CT scan, and the patient underwent further surgery, which revealed a tumour. Histology of the resected mass revealed a microcystic adnexal carcinoma. This case illustrates the diagnostic challenges of atypical inguinal swellings.

Keywords

Microcystic Adnexial Carcinoma, Inguinal Swelling, Inguinal Hernia

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1. Introduction

Painful inguinal swellings are a frequent clinical presentation in general surgery, often associated with conditions such as inguinal hernias [1]. Analysis of the pulsatile characteristics of the pre-existing swelling prior to the onset of atypical pain, or the recurrence of such swellings after surgery, should alert patients to the possibility of rare diagnoses, such as adnexal tumors derived from the sweat glands in the form of adnexal microcystic carcinoma [2] [3]. These are rare cutaneous malignant tumours, representing approximately 1% of cutaneous tumours, with metastatic potential, which are managed medico-surgically with a poor prognosis [3]-[5].

2. Observation

A 62-year-old man consulted for a painful right inguinal swelling. The history revealed an identical swelling that had appeared a few months previously and had been followed up in another hospital where he had undergone a hernia repair 2 months previously for a so-called strangulated right inguinal hernia. Immediately postoperatively, he reported a progressive increase in the intensity of inguinal pain, first paresthesia-like, then burning or electric discharge-like, becoming very intense and assessed at 8/10 on the visual numerical scale. Clinical examination on admission revealed a painful right inguinal mass, oval with a long axis of 5 cm and a short axis of 3 cm, hard and non-mobile in relation to the deep plane. The skin was thickened and wrinkled, with keloids from the old surgical scar (Figure 1).

Figure 1. (A) Right inguinal swelling with a retractile operative scar; (B) Intraoperative image after placement of the auto-static retractor, showing cartilaginous fibrous tissue in the background.

The diagnosis of fibrosis of the surgical scar or ligation of the right ilioinguinal nerve was suggested as a differential diagnosis for iatrogenic injury of nerve.

Corticosteroid infiltration was performed as a first-line treatment, resulting in temporary pain relief. One week after the infiltration, the pain returned and the swelling persisted, requiring further investigation.

Ultrasound revealed a tissue formation opposite the scar from the right hernia repair, infiltrating the muscle plane, with an ill-defined relationship with the right femoral vessels. Abdominal and pelvic CT scan followed by angioscan revealed a right inguinal tissue mass infiltrating the rectus abdominis and internal transverse muscles, enveloping the homolateral spermatic cord, without vascular invasion of the right femoral vessels (Figure 2).

Figure 2. Right inguinal tissue mass infiltrating the rectus abdominis and internal transverse muscles and enveloping the homolateral spermatic cord without vascular invasion.

The patient underwent reoperation with wide excision of the inguinal mass (Figure 1(B)). The surgical specimen was sent for anatomopathology examination. Histological analysis showed a histological appearance of a microcystic adnexal carcinoma (Figure 3).

Figure 3. Iconography (D) showing syringomatous aspects at low magnification, in the form of a tadpole-shaped ductal structure with numerous glandular structures infiltrating the dermis and hypodermis compatible with a microcystic adnexal carcinoma. The patient was referred for chemotherapy but was unable to attend the sessions. The course was marked by the occurrence of a serious cranioencephalic trauma which led to the patient’s death.

3. Discussion

Microcystic adnexal carcinoma is a rare malignant cutaneous adnexal tumour characterised by glandular and follicular differentiation. It is also known as sclerosing sweat duct carcinoma [1]. It is a slow-growing, locally aggressive, invasive and destructive tumour that is often diagnosed late because of its insidious course and the similarity of its symptoms to common pathologies [2] [3].

The clinical appearance of adnexal carcinomas is often nonspecific and only histopathological examination enables them to be accurately identified. Microcystic adnexal carcinoma occurs in younger subjects as a hard, scleroderma-like tumour, clinically similar to scleroderma-like basal cell carcinoma, which is its main differential diagnosis [4]-[10]. However, some authors in literature often report a mean age of diagnosis in the 5th or 6th decade. This is the case of our patient who is 62 years old.

Initial confusion with a strangulated hernia illustrates the importance of rigorous clinical assessment and multidisciplinary management. Imaging studies, such as ultrasound and CT scans, play a crucial role in orienting the diagnosis in the event of an atypical mass [6] [9] [11] [12].

In terms of treatment, there are no codified rules and no official recommendations for management. In all cases, excision with a healthy margin is recommended; the size of this margin being discussed, which may be 1 to 2 cm for forms with a propensity for local or general dissemination [5] [7] [13] [14]. Micrographic surgery may be considered in certain types. Microcystic adnexal carcinoma has metastatic potential. While it can invade surrounding tissues and has a high rate of recurrence, distant metastasis is uncommon [13]-[15]. Only a few cases of metastasis have been reported in literature to date [16]-[20]. Additional treatment with radiotherapy or chemotherapy should be discussed on a case-by-case basis [5] [6] [9]. Local recurrence and the possibility of metastases are rare, but require long-term follow-up [16] [17] [20]. The natural progression of this patient’s cancer is unknown. The patient’s death from an unrelated trauma is a critical piece of the case history.

4. Conclusion

This case highlights the diagnostic difficulties of recurrent inguinal swellings and underlines the importance of considering rare aetiologies such as adnexal tumours. Careful clinical assessment, combined with targeted additional investigations, is essential to avoid misdiagnosis and ensure appropriate management.

Acknowledgements

The authors would like to thank Dr. AHOMADEGBE M. for assistance with the histological diagnosis.

Ethical Aspect

Parental consent has been obtained for the use of patient data, and no image allows identification.

Conflicts of Interest

The authors declare no conflicts of interest regarding the publication of this paper.

References