Paraneoplastic Eosinophilia in Malignant Melanoma
Authors: S A J Rule, P Waterhouse, C Costello, S Retsas
Journal: Journal of the Royal Society of Medicine (1993)

A 64-year-old woman had a cutaneous primary malignant melanoma excised from the right knee in May 1990. The lesion measured 4.5 mm in thickness according to Breslow and infiltrated into Clark's level W. In September 1990 she developed a regional lymph node metastasis for which she had an inguinal block dissection. One lymph node was totally replaced by tumour. She received no adjuvant treatment. On 11 January 1991 a subcutaneous metastasis developed in the right upper thigh which was resected and histologically confirmed. On 31 January 1991 a computerized tomography (CT) scan of the chest, abdomen and pelvis revealed no metastases in the lung and mediastinum but disease in the right axilla as well as extensive abdominal lymphadenopathy with infiltration of the left lobe of the liver by tumour. A full blood count taken at this time demonstrated a white cell count of 32xlO9/l with a marked neutrophilia and left shift, the rest of the count was normal. At this point the patient was referred to the Medical Oncology Unit at the Westminster Hospital for further management. The lymphadenopathy progressed clinically and by 21 February 1991 a chest X-ray demonstrated widespread pulmonary metastases and a left pleural effusion which had not been present on a CT scan ofthe thorax 3 weeks earlier. A full blood count showed a dramatic change with the white cell count having risen to 134xlO9/l with an eosinophilia of 40.2x 109/l. A bone scan at this time revealed a single area of activity in the skull and a bone marrow aspirate and trephine biopsy demonstrated a very active marrow with 35% of all nucleated cells being eosinophils or their precursors. There was no evidence of malignant infiltration in the biopsy specimen. During this 3 week period the patient had received no new drugs, developed no specific symptoms and had no demonstrable parasitic infection. Chemotherapy was commenced on 22 February 1991 with the DJV3F regime, as previously described'. This combination incorporates vinblastine, carboplatin, vindesine, DTIC, vincristine and fotemustine administered on alternating cycles every 2-3 weeks. Following the vinblastine, carboplatin and vindesine components there was a dramatic fall in the eosinophil count which on 18 March had fallen to 6.7x 1091/1. However, her malignant melanoma progressed against treatment and the patient died on 21 April 1991. A post-mortem examination confirmed widespread metastases from malignant melanoma involving both lungs as well as many other organs as the cause of death. Eosinophilia occurs in association with a number of neoplastic diseases, in particular carcinoma ofthe lung, acute lymphoblastic leukaemia and lympho-reticular malignancies especially Hodgkina disease2. Although up to 15% of patients with Hodgkins disease have a raised eosinophil count it is rarely marked3. To our knowledge marked eosinophilia has only been described in one patient with malignant melanoma4, although slight increases in number have been reported in up to 15% of patients prior to therapy'. We retrospectively looked at 30 hospital notes ofpatients with disseminated malignant melanoma randomly selected from a computerized database of 1300 patients registered with the Medical Oncology Unit at Westminster Hospital, in whom manual differential blood counts had been performed prior to treatment. Five (17%) of these had eosinophil counts outside the normal range ofour laboratory (0.04-0.4x10911; mean 0.6, range 0.5-0.9). The rapid development of eosinophilia in the patient described appeared to coincide with the accelerated progression of the melanoma, particularly in the chest where widespread metastases became apparently established over a 3 week period. It has been shown that serum extracts from a patient with a bronchogenic carcinoma stimulated the production of eosinophil colonies from bone marrow and a peptide acting as an eosinophilopoietin has also been isolated6. Perhaps a similar mechanism is involved in this case. It is of interest that while the eosinophilia largely resolved following the commencement ofchemotherapy there was no apparent clinical response.